Titanic corrosion

EDITOR’S DESK The Editor and his team of Editorial Board is thankful to the Contributors, who have submitted interesting articles to this issue. Teaching the blind group theory is a novel attempt. One it will be possible to do so. A wide variety of papers have been submitted. They will be useful to the Readers. Some people say 30+30+30 = 90 kg, the weight of Einstein. But this cannot be correct when academicians think of KNOLEDGE, EXPERIENCE, ACHIEVEMENTS, AWARDS, CONTRIBUTION etc., Many Academicians understand and do admit, except a few! The Editor-in-Chief is thankful to The Editorial Team and Mrs J Revathi, HOD, Science Departments, and Mrs M Praveena and Mrs D Preetha of Chemistry Department and Sr Renita, SHIATS, Deemed University) Allahabad for their support and help in bringing out this Edition.

IJNCSE Volume 3: Issue 4: October 2016 Editors : Dr. S. Rajendran, Mrs. A. Christy Catherine Mary and Ms. P. Nithya Devi S.NO

TITLE, AUTHORS

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“SEM AS SURFACE ANALYSIS TOOL”

1

S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama

1-8

Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold

2

Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg

9-27

A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj

3

4 5

6

Cyclic Voltammetric Study Of Protective Film Formed By Tri Sodiumcitrate In Simulated Concrete Pore Solution On Mild Steel A.Suriyaprabha, J. Sathiyabama and S. Rajendran Application Of Electrochemical Studies In Corrosion Inhibition Of Stainless Steel 18/8 In Oil Well Water Using

Trisodium Citrate As Inhibitor

28-43

44-56

K.Nithya And, S.Devi Meenakshi Application of AC impedence spectra in corrosion inhibition studies P.Nithya Devi , J.Sathiyabama , S.Rajendran R, Joseph Rathis and S .Santhana Prabha Can people implanted with orthodontic wires made of thermoactive superelastic shape memory alloy and 22 k gold take syzygium cumini fruit juice oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha ,

57-79

80-87

Dr. S. Rajendran

7

8

Comparitive Analysis Of Corrosion Inhibition Studies On Various Metals In Oil Well Water Using Trisodium Citrate As Inhibitor M.Lavanyaa and M.suganya. Teaching Of Group Theory To The Blind Student Through Violin A.John Amalraj, J.Wilson Sahayaraj, S.Arulanda Jothi, V. Dharmalingam and Susai Rajendran

88-103

104-115

Corrosion Inhibition By Natural Dyes

9

V.Johnsirani, J.Sathiyabama and SusaiRajendran

116-130

10

Decolourisation Of Dyes Of Textile Industries By Biochemical Methods T. Marimuthu, S.Rajendran

131-141

S.NO

TITLE, AUTHORS

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Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract Of

11

Neem

142-155

S.Shanmugapriya, S.Rajendran , P.Prabakar, N.karthika Green Synthesis Of Copper Nanoparticles Using Delonix Elata Flower Extract

12 13 14 15

16

M.Suganya and G.Valli Applications of Cyclic voltammetry in Corrosion inhibition studies M.Pandiarajan, S.Rajendran and J. Sathiya bama Application Of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran , and J.Sathiyabama Comparitive analysis of corrosion inhibition studies on various metals in oil well water using trisodium phosphate as inhibitor S.Anusuya and S.Devi Meenakshi Application of electrochemical studies in corrosion inhibition of stainless steel 18/8 in oil well water using trisodium phosphate as inhibitor

156-165 166-180 181-203 204-215

216-222

M.Abinaya and S.Devi meenakshi

17

18

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Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn 2+ and N-cetyl-N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha, A. Sahaya Raja , Susai Rajendran Synthesis and studies on anionic transition metal complexes with tetraaza protonated 2,3,8,9-tetrahydroxy-1,4,7,10-teraazacyclododecane-1,3,7,9-tetraene as cation Angusamy selvan Corrosion Resistance Of Super Elastic Nickel - Titanium Alloy In Artificial Saliva In Presence Of Almox 250mg Tablet S.Rajendran, A.Krishnaveni, and G.Muthukumar

223-245

246-253

254-266

Cyclic Volammetry Study Of Carbon Steel In Sea Water In The Presence Of Tyrosine-

20

Zn2+ System

267-279

S. Gowri1, J. Sathiyabama, S. Rajendran

21

Correlation between Quantum Chemical Parameters of Aminoacid inhibitors and their corrosion inhibition efficiencies J. AngelinThangakani, S. Rajendran and J. Sathiabama

280-301

Synthesis and Characterisation of SiO2/Ni-Cu Nanocomposite for the Dye Degradation

22

J.Maria Praveena, A.Sahaya Raja, J. Sathiyabama, V.Prathipa

302-311

23

Hydrophobicity And Corrosion Inhibition V.R.Nazeera Banu and S.Rajendran

312-326

24

Electrochemical Decolourisation Process of Methylene Blue Dye in the Presence of NaCl at Platinised Titanium Electrode M.Vijayalakshmi, B.Vanmathi A.Sahaya Raja, J. Sathiyabama, V.Prathipa

327-336

25

Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama, S.Rajendran and S.Senthil Kumaran

337-350

26

Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama ,S.Rajendran

351-358

S.NO

TITLE, AUTHORS

27

Corrosion Inhibition of Aluminium in an aqueous solution at pH 10 by adipic acid - Zn2+ system P.Satyabama ,S.Rajendran

28

29

30

31

32

33

34

35

36

37

38

39

40

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3thiazol-2yl)-hydrazones S. R. jayapradha & S. Muthusubramanian The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha, A. John Amalraj, V. Dharmalingam, J. Wilson Sahayaraj and P. Johnraj Can people implanted with orthodontic wires made of thermoactive superelastic shape memory alloy and 22 k gold take syzygium cumini fruit juice oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya, Dr. M. Sangeetha , Dr. S. Rajendran Corrosion behaviour of carbon steel in isoelectric point and nearly neutral aqueous medium by L – arginine and zinc ion as a synergist S.Sulochana, P.Revathi, A.Sahaya Raja, J. Sathiyabama, V.Prathipa Cobalt Complex Of 8-Hydroxyquinoline Derivative As Potential Corrosion Inhibitor For Mild Steel In Aqueous Sodium Chloride Solution S. S. Syed Abuthahir, A. Jamal Abdul Nasser, M.Muhammed Azar, K.Muhammed Rashid , S. Rajendran Decolourisation Of Dyes Of Textile Industries By Biochemical Methods T. Marimuthu, S.Rajendran Influence of “SUGAR CANE JUICE” on the corrosion resistance of orthodontic wires in artificial saliva A.Christy Catherine Mary, V.Jeslina, A.. Subhashini mary, P.Geethanjali, G.Bowriya, J.ClaraAngelin S.Rajendran, J.Jeyasundari Influence of “SUGAR CANE JUICE” on the corrosion resistance of Ni-Ti alloy in presence of artificial saliva A.Christy Catherine Mary , A.S.Arshiya Fathima, X. Susmitha, D.Keerthana, A.Infant Deepa S.Rajendran, J.Jeyasundari Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari,

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari

Can people implanted with Thermoactive alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary,P.Nandhini, U.Veeranagammal, S.Selvarathinam, Kohila S.Rajendran, J.Jeyasundari Inhibition of acidic corrosion of mild steel by some organic compounds. Geetha M.B, Susai Rajendran Applications Of Uv-Visible Absorption Spectroscopy In Corrosion Inhibition Study N.Karthiga, S.Rajendran and P.Prabhakar

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Sythesis And

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Characterisation Of Doped Zn

521-537

R. Elcy Mettilda

42 Corrosion Inhibition By An Aqueous Extract Of Ervatamia Divaricata Karthika And Dr.P.Shanthy

43

538-545

Removal Of Phosphate From Aqueous Solution By Adsorption Using Abutilon Indicum Seed And Its Peel - A Comparitive Study

546-557

D.Preetha, Dr.G.N.Kousalya

44

Corrosion resistance of mild steel in simulated concrete pore solution in presence of Green inhibitor-Azadirachta indica stick

45

46

A.Christy Catherine Mary ,K.Janaki, R.Kasthuri Devi, A.Arockia Jenifer, V.Kalai Selvi, P.Backiya Lakshmi S.Rajendran Corrosion Inhibition of SS18/8 in simulated concrete pore solution in presence of Green inhibitor-Azadirachta indica stick A.Christy Catherine Mary,V.Bharathi, A.Arockia Jesi ,M.Thangaleswari , F.Flori Jenifer, N.Rathi Devi, S.Rajendran

573-583

Phytochemical Analysis, Anticorrosion and Pharmacological Studies on Kurunthumul Thazhai Oil and Kurunthumul Thazhai Extract

48

565-572

Synthesis of an effective solar cells thin film by SILAR method.

S.Shanmugapriya, S.Princy Beatrose, P.Pradeepa, R.Priya, A.Christy Catherine Mary, Susai Rajendran , P.Nithya Devi. 47

558-564

584-594

N. Muniyappan, M. Pandeeswaran, J. Antony Lisa, J. Infanta Tresa, S. Divya Barathi and K. Gowsalya Water extract of Vitex negundo as a green corrosion inhibitor for the corrosion of carbon steel: An electrochemical and surface morphological approach

595-603

P.Angel, P. Arul moli, A.Sahaya Raja, J.Sathiyabama, V.Prathipa

49

50

Corrosion Inhibition By Malonic Acid K.Rajesh ,P.Satyabama, S.Rajendran

604-616

Applications of EDS in corrosion inhibition study D’Souza, R Chattree A,Rajendran S

617-627

Invited Talk - Titanic corrosion

Prof Dr Susai Rajendran

Invited Talk - Titanic corrosion Prof Dr Susai Rajendran Research Director, Department of Chemistry, St Antony’s College of Arts and Sciences, Amala Annai Nagar, Thamaraipadi, Dindigul- 624 005, India. Email: [email protected], 944361628 Abstract In the process of corrosion, electrons are released. Proper steps should be taken to control the process of corrosion. Otherwise many accidents may take place in industry and walks of life. Many catastrophes in history are due to corrosion. To cite examples, the following incidents may be mentioned: The Aloha Incident: Bhopal Accident, Swimming pool roof collapse (1985, Switzerland), Trans Alaska pipeline, Stewarton freight train crash, Accident14, Silver bridge collapse and Titanic corrosion. The main reason for Titanic corrosion is considered as galvanic corrosion. The dissimilar metals of the hull and rivets, bathed in electrically conductive seawater, might have created a circuit that slowly flecked away and weakened the rivets. Keywords: Titanic corrosion, two metal corrosion, galvanic corrosion, corrosion sank Titanic

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran



1. Introduction Corrosion is a natural, spontaneous and thermodynamically favourable process. It is the expression of the desire of the metal to go back to its original state of ore. Even though the rate corrosion can be controlled corrosion cannot be completely prevented. We cannot prevent death; but we can only postpone death. We are born out of ashes and we will go back to ashes. The philosophy of corrosion reminds us that every day we are marching towards our graveyard whereon the elegy will be “Here lies a soul that dedicated his life time for the cause of control of corrosion”. 2. Consequences of Corrosion Corrosion leads to many inconveniences which include over design of machines, decrease in their efficiency, shut down of industries, accidents in industries, collapse of bridges and loss of human lives. 3. Catastrophes due to Corrosion Moreover the reason assigned to many accidents in the history is mainly corrosion. To list a few are: 1. The Aloha Incident 2.

Bhopal Accident

3.

Swimming pool roof collapse (1985, Switzerland)

4.

Trans Alaska pipeline

5.

Stewarton freight train crash

6.

Accident-14

7.

Silver bridge collapse

8.

Titanic corrosion




4. Titanic Corrosion 4.1 Corrosion Sank the Unsinkable Titanic The Titanic ship (Fig 1) was a victim of rust. The Titanic was held together by 3 million rivets made with a different type of iron than the hull plates. And once the hull was finished, the ship sat in seawater for a year while the inside was furnished. The dissimilar metals of the hull and rivets, bathed in electrically conductive seawater, might have created a circuit that slowly flecked away and weakened the rivets(GALVANIC CORROSON.Fig.1.1).[If two dissimilar metals are in contact through an electrolyte, the more anodic one undergoes corrosion. For example if aluminium and copper are in contact, aluminium undergoes corrosion] One of the last photos taken before the ship's maiden voyage shows a pattern that suggests the rivets were rusting faster than the hull plates.

Fig.1.1 Galvanic Corrosion Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran



The Titanic collision with the iceberg could have popped the weakened rivets, which would explain a clinking sound reported by survivors. The hull did not rip open, but a long opening just an inch wide between the hull plates could have sunk the ship. Video of the wreckage shows a narrow opening in the unburied part of the bow. It is about at the level where the iceberg would have struck, and it is right where rivet popping could occur. That caused the Titanic to sink. The following information supports the fact that corrosion contributed to the sinking of the Titanic: 1. She was launched to be fitted out at dockside almost a year before her maiden voyage, 2. During the year in seawater, there is a strong possibility that stray currents from DC equipment caused accelerated corrosion, 3. The rivet iron was different from the hull plate iron by design. The rivet iron needed to be maleable and therefore consisted of a higher level of slag inclusions, 4. During the year at dockside, corrosivity of the rivet iron could therefore have been higher than the hull plate iron. Galvanic corrosion of the rivet iron is likely during that period of time, 5. Photos and video taken by Robert Ballard during his 1985 and 1986 expeditions to the Titanic show preferential corrosion of the rivets in some areas, 6. Inspection of the "big piece" which was retrieved from the ocean bottom also shows this same preferential corrosion in some areas. All of this evidence points towards weakening of the hull/rivet structure, enhancing the rivet popping mechanism which caused the Titanic to sink. 4.2 The RMS Titanic The RMS Titanic (Fig 2) was an Olympic-class passenger liner owned by British shipping company White Star Line and built at the Harland and Wolff shipyard in Belfast, Ireland. At the time of her construction, she was the largest passenger steamship in the world. Shortly before midnight on 14 April 1912, four days into the ship's maiden voyage, Titanic hit an iceberg and sank two hours and forty minutes later, early on 15 April 1912. The sinking resulted Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran



in the deaths of 1,517 of the 2,223 people on board, making it one of the deadliest peacetime maritime disasters in history. The high casualty rate was due in part to the fact that, although complying with the regulations of the time, the ship did not carry enough lifeboats for everyone aboard. The ship had a total lifeboat capacity of 1,178 people, although her maximum capacity was 3,547. A disproportionate number of men died due to the women-and-children-first protocol that was followed.The Titanic used some of the most advanced technology available at the time and was popularly believed to have been described as "unsinkable." It was a great shock to many that, despite the extensive safety features, the Titanic sank. The frenzy on the part of the media about Titanic's famous victims, the legends about the sinking, the resulting changes to maritime law, and the discovery of the wreck have contributed to the continuing interest in, and notoriety of, the Titanic.




4.3 The Titanic iceberg The iceberg (Fig.3) suspected of having sunk the RMS Titanic. Contains the infamous "red smear" and was found in the same vicinity as many bodies and debris from the ship. They do not know how big it was.




Photograph of an iceberg in the vicinity of the RMS Titanic's sinking taken on 15 April 1912 by the chief steward of the liner Prinz Adelbert who stated the berg had red anti-fouling paint of the kind found on the hull from below Titanic's waterline. 4.4 List of passengers and crew members on board RMS Titanic The list of passengers and crew members on board RMS Titanic is given in Table1.

Category

Number aboard

Number of survivors

Percentage survived

Number lost

Percentage lost

First class

329

199

60.5 %

130

39.5 %

Second class

285

119

41.7 %

166

58.3 %

Third class

710

174

24.5 %

536

75.5 %

Crew

899

214

23.8 %

685

76.2 %

Total

2,223

706

31.8 %

1,517

68.2 %

Table 1: Survivors, victims and statistics




5. Possible factors in the sinking

It is well established that the sinking of the Titanic was the result of an iceberg(Fig.4 ) collision which fatally punctured the ship's front five watertight compartments. Less obvious however are the reasons for the collision itself (which occurred on a clear night, and after the ship had received numerous ice warnings), the factors underlying the sheer extent of the damage sustained by the ship, and the reasons for the extreme loss of life. 5.1 Construction and metallurgy Originally, historians thought the iceberg had cut a gash into Titanic's hull. Since the part of the ship that the iceberg damaged is now buried, scientists used sonar to examine the area and discovered the iceberg had caused the hull to buckle, allowing water to enter Titanic between her steel plates.The steel plate used for Titanic hull was of 1 to 1½ inch (2.5 to 3.8 cm) thickness. A detailed analysis of small pieces of the steel plating from the Titanic's wreck hull found that it was of a metallurgy that loses its elasticity and becomes brittle in cold or icy water, leaving it vulnerable to dent-induced ruptures. 5.2 High content of phosphorus and sulphur The pieces of steel were found to have very high content of phosphorus and sulphur (4× and 2× respectively, compared with modern steel), with manganese-sulphur ratio of 6.8:1 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran



(compared with over 200:1 ratio for modern steels). High content of phosphorus initiates fractures, sulphur forms grains of iron sulphide that facilitates propagation of cracks, and lack of manganese makes the steel less ductile. 5.3 Unsuitable Titanic steel The recovered samples were found to be undergoing ductile-brittle transition in temperatures of 90 °F (32 °C) for longitudinal samples and 133 °F (56 °C) for transversal samples, compared with transition temperature of −17 °F (−27 °C) common for modern steels: modern steel would only become so brittle in between −76 °F and −94 °F (−60 °C and −70 °C). The Titanic's steel, although "probably the best plain carbon ship plate available at the time", was thus unsuitable for use at low temperatures .The anisotropy was probably caused by hot rolling influencing the orientation of the sulphide stringer inclusions. The steel was probably produced in the acid-lined, open-hearth furnaces in Glasgow, which would explain the high content of phosphorus and sulphur, even for the time. 5.4 More fragile rivets Another factor was the rivets holding the hull together, which were much more fragile than once thought. From 48 rivets recovered from the hull of the Titanic, scientists found many to be riddled with high concentrations of slag. A glassy residue of smelting, slag can make rivets brittle and prone to fracture. Records from the archive of the builder show that the ship’s builder ordered No. 3 iron bar, known as “best”—not No. 4, known as “best-best”, for its rivets, although shipbuilders at that time typically used No. 4 iron for rivets. The company also had shortages of skilled riveters, particularly important for hand riveting, which took great skill: the iron had to be heated to a precise colour and shaped by the right combination of hammer blows. The company used steel rivets, which were stronger and could be installed by machine, on the central hull, where stresses were expected to be greatest, using iron rivets for the stern and bow. Rivets of “best best” iron had a tensile strength approximately 80% of that of steel, “best” iron some 73%.Despite this, the most extensive and finally fatal damage Titanic sustained at boiler rooms No. 5 and 6 was done in an area where steel rivets were used. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran



6. Conclusion Corrosion sank The Titanic ship, which could not complete even the Maiden Voyage. Galvanic corrosion is attributed to collapse of Titanic ship. The dissimilar metals of the hull and rivets, bathed in electrically conductive seawater, might have created a circuit that slowly flecked away and weakened the rivets.

Received: 15-09-2016 Accepted: 22-09-2016


“Plant extract mediated Synthesis of Nano

particles and its antibacterial activity”

Dr . J. JEYA SUNDARI



Dr . J. JEYA SUNDARI Assistant professor & Research Supervisor/Guide, PG & Research Department of Chemistry, NMSSVN College,Madurai-625019 Introduction 1.1 INTRODUCTION TO NANOTECHNOLOGY The prefix nano is derived from Greek word nanos meaning “dwarf” in Greek that refers to things of one billionth (10-9 m) in size.The primary concept of nanotechnology was presented by Richard Feynman in a lecture entitled “There's plenty of room at the bottom” at the American Institute of Technology in 1959. Nanotechnology is the application of science to control matter at the molecular level. Tremendous growth in nanotechnology has opened up novel fundamental and applied frontiers in materials science and engineering, such as nano-biotechnology, quantum dots, surface-enhanced Raman scattering (SERS), and applied microbiology.It is gaining importance in areas such as mechanics, optics, biomedical sciences, chemical industry, electronics, space industries, drug-gene delivery, energy science, catalysis, optoelectronic devices, photo-electrochemical applications, and nonlinear optical devices.Nano-particles are usually 0.1 to 1000 nm in each spatial dimension and are commonly synthesized using two strategies: top-down and bottom-up.Nano-particles have characteristic physical, chemical, electronic, electrical, mechanical, magnetic, thermal, dielectric, optical and biological properties.Nano-particles has pronounced effect on the physical properties that significantly differ from the bulk material. These physical properties are caused by their large surface atom, large surface energy, Spatial confinement and reduced imperfections.It is gaining importance in areas such as mechanics, Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.

Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary



Dr . J. JEYA SUNDARI optics, biomedical sciences, chemical industry, electronics, space industries, drug-gene delivery, energy science, catalysis, optoelectronic devices, photo-electrochemical applications, and nonlinear optical devices.Nano-particles are usually 0.1 to 1000 nm in each spatial dimension and are commonly synthesized using two strategies: top-down and bottom-up.Nano-particles have characteristic physical, chemical, electronic, electrical, mechanical, magnetic, thermal, dielectric, optical and biological properties.Nano-particles has pronounced effect on the physical properties that significantly differ from the bulk material. These physical properties are caused by their large surface atom, large surface energy, Spatial confinement and reduced imperfections 1.2INTRODUCTION TO METALLIC NANOPARTICLES

Metalloid and Metals utilized in Nanoscale form In recent years nano-materials,

specifically metal nano-particles, have received particular

interest in diverse field ranging from material science to biotechnology.Nano-materials have potential applications in electronics , photonics, catalysis, information storage, chemical sensing

, imaging, environmental remediation, drug delivery and biological labelling.The

optical, electronic, and catalytic properties of metal nano-particles are greatly influenced by their size, shape, and crystal structure. For example, silver (Ag) and gold (Au) nano-crystals of different shapes possess unique optical scattering responses.Gold and silver nanoparticles are the most common ones used for biomedical applications and in emerging interdisciplinary field of nano-biotechnology. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.




Dr . J. JEYA SUNDARI Various methods of Metallic Nanoparticles synthesis Laser ablation Inert Gas Condensation Sol-Gel Process Hydrothermal & solvothermal synthesis Colloidal method Pyrolysis Chemical reduction procedure Green synthesis GREEN SYNTHESIS OF METALLIC NANOPARTICLES Using naturally occurring reagents such as vitamins, sugars, plant extracts, biodegradable polymers, and microorganisms as reductants and capping agents could be considered attractive for nanotechnology.Greener synthesis of nanoparticles provides advancement over other methods as it is simple, cost-effective, and relatively reproducible and often results in more stable materials.The green synthesis of MNPs should involve three main steps based on green chemistry perspectives: 1. The selection of a biocompatible and nontoxic solvent medium, 2.The selection of environmentally benign reducing agents, 3. The selection of non-toxic substances for stabilization of the nanoparticles.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.




Dr . J. JEYA SUNDARI Classification of Various Modes of Green Synthesis:

Classification of nanoparticles Liposomes Superparamagnetic nanoparticles Fullerenes: buckyballs and carbon nanotubes Dendrimer Quantum dots Liquid crystals

Fig – Different classes of nanoparticles. (A) Nanoparticle in liposomes; (B) superparamagnetic nanoparticle; (C) nanotube;(D) dendrimer; (E) quantum dots with changing optical properties Nanoparticle classification Dimensionality 1D nanomaterials 2D nanomaterials Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.




Dr . J. JEYA SUNDARI 3D nanomaterials

Morphology Helices, zigzags,belts,nanowires spherical, oval, cubic, prism, helical, or pillar Nanoparticle uniformity and agglomeration Dispersed aerosols, as suspensions/colloids, or in an agglomerate state ANTIMICROBIAL PROPERTIES OF METAL NANOPARTICLES Nanoparticles show good antibacterial properties arising from their large surface area to volume ratio providing desirable contact with bacterial cell One of the cytotoxicity mechanisms is the result of nanoparticles uptake by the bacterial cells as they are able to penetrate the bacterial cell wall The degree of dispersion of NPs in water solution seems to play an important role in antibacterial mechanism

Fig: Suggested mechanism of antibacterial nanoparticles activity Applications of metal nanoparticles Catalysis Labelling Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.




Dr . J. JEYA SUNDARI Sensors Drug delivery Cancer therapy Bacteriocidal Agent Anti Inflammatory Effect Electronics Transportation and telecommunication Biomedical applications Nanoscaffolds Antimicrobial nanopowders and coatings Gene transfection Pollution remediation Cosmetics Textiles Paints



“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama

“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi[a], SusaiRajendran[b] and J.Sathiyabama[c] Department of Chemistry& Physics, Nadar Saraswathi College of Arts & Science, Theni. Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul women 624 005,Tamil Nadu, India. Email: [email protected] P.G and Research Department of Chemistry, G.T.N. Arts College, Dindigul. Abstract Scanning Electron Microscopy (SEM) has been used to reveal information about the sample including external morphology (texture), chemical composition, and crystalline structure and orientation of materials making up the sample.In the present study, SEM were used to study the corrosion inhibition performance among the system, simulated concrete pore solution (SCPS) (SCP with inhibitors such as sodium molybdate, trisodium citrate, trisodium phosphate, sodium potassium tartrate and potassium dichromate. The SEM Micrographs of the presence of inhibitors complex formed on the steel rebar surface shows the smooth surface, but in the absence of inhibitors like in presence of SCPS solution shows the roughness of the rebar surface. Thus, hus, SEM studies inferred the presence of inhibitors such as Sodium molybdate, trisodium citrate, trisodium phosphate, sodium potassium tartrate and potassium dichromate creates a thin protective film, which inhibits rebar steel dissolution. National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India 1 Int J Nano CorrSci and Engg 3(4)(2016) 1-8 Editors: Dr S Rajendran,

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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama Keywords:SCPS Solution, SEM, Principle of SEM,

1. Introduction Corrosion is ubiquitous and it is a significant unhealthy process in the construction of many infrastructure systems.Several research papers have investigated the corrosion behavior of metals in presence of simulated concrete pore solution (SCPS) [1-12].Many different methods have been proposed to address rebarcorrosion in reinforced concrete structures, such as barrier layers,cathodic protection and corrosion inhibitors. Corrosion inhibitorsmay be a good way to prevent and/or control reinforcing steel corrosion because they are easy to apply and less costly than other preventionmethods [13,14]. In general, the inhibitors react with the corrosion product, initially formed, resulting in a cohesive and insoluble film on the metal surface [15, 16].Some examples of anodic inorganic inhibitors are nitrates, molybdates, sodium chromates, phosphates, hydroxides and silicates act by a reducing the anodic reaction, that is, blocks the anode reaction and supports the natural reaction of passivation metal surface, also, due to the forming film adsorbed on the metal. Inorganic cathodic inhibitors are the ions of the magnesium, zinc, and nickel that react with the hydroxyl (OH-) of the water forming the insoluble hydroxides as Mg (OH)2, Zn(OH)2, Ni(OH)2 which are deposited on the cathodic site of the metal surface,protecting it. The power of inhibitors such as Sodium molybdate, trisodium citrate, trisodium phosphate, sodium potassium tartrate and potassium dichromate, for rebar steel in simulated concrete pore solution (SCPS) has been investigated utilizing the Scanning electron microscopy.SEM is frequently employed in corrosion studies due to its powerful magnification property; where it is used to evaluate the surface examination on rebar steel specimens. SEMs are also easy to operate and work fast. Despite the successful applications of SEM in corrosion science, many researchers havestatedthat, SEM has been used to evaluate the protective film formed on the carbon steel metal surface. In the present study, SEM is being used to evaluate the external morphology (texture) ie., surface film formed on the surface. 2. Experimental Section 2.1 Metal Specimens National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India

Int J Nano CorrSci and Engg 3(4)(2016) 1-8 Editors: Dr S Rajendran,

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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama Rebar steel specimens were used in the present study with Composition (wt %): 0.05 S, 0.05 P, 0.5 Mn, 0.2 C, and the rest iron of size 1 × 1 cm2were used for the study. 2.2 Simulated concrete pore Solution (SCPS) A saturated solution of calcium hydroxide is used in the present study. 2.3 Surface Analytical Techniques Rebar Steel specimens were immersed in the SCPS solution in absence and presence of inhibitor for 3 days. Then the specimens were removed and rinsed with running water quickly. After fter washing, specimens were dried and finally analyzed using SEM. SEM

3. Instrumentation The instrument has the following components like electron source, condensing lens, scan coil, objective lens, detector ector amplifier and a monitor. The samples are usually mounted on a double adhesive tape coated with gold in vacuum using a HITACHI HUS-5 vacuum evaporator. If the samples are conducting, they are directly mounted onto the sample holder with silver paste. The less-conducting samples are re to be gold gold-sputtered sputtered before talking it onto the specimen stage of the SEM. There are many advantages of using the SEM instead of a light microscope. It has a large depth of field, which allows a large amount of the sample to in the focus at one time. It also produces images of high resolution, which means that closely spaced features can be examined at a high magnification (Fig. 1) Instead of light, the SEM uses electrons to see 3-D 3 images and the SEM operation proceeds as,Air pumped out (vacuum) →

e- gun emits beam of high energy electrons → e- beam focused

via lenses → Scanning coils move beam across sample → Secondary electrons are “knocked off” surface → Detector counts electrons → Image given by e- Resolution ~5 nm

National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India 1 Int J Nano CorrSci and Engg 3(4)(2016) 1-8 Editors: Dr S Rajendran,

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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama

Fig. 1 Schematic diagram of the electron emission in SEM

Fig. 2 Schematic diagram of the setups of SEM

4. Principle of SEM National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India 1 Int J Nano CorrSci and Engg 3(4)(2016) 1-8 Editors: Dr S Rajendran,

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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama A typical SEM instrument, showing the electron column, sample chamber, EDS detector, electronics console, and visual display monitors. The scanning electron microscope (SEM) uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens. The signals that derive from electron-sample interactions reveal information about the sample including external morphology (texture), chemical composition, and crystalline structure and orientation of materials making up the sample. Areas ranging from approximately 1 cm to 5 microns in width can be imaged in a scanning mode using conventional SEM techniques (magnification ranging from 20X to approximately 30,000X, spatial resolution of 50 to 100 nm). The SEM displays finer morphological details of a specimen surface. The resolution of SEM is determined by the size of electron beam arriving at the specimen with sufficient current intensity for generating a secondary electron signal of good signal to noise ratio for image formation. 5. Applications of SEM An extensive series of SEM measurements on surface morphological studies on metal surface have been made by researchers. Selected examples of the types of results will be presented as follows:

Konstantinos et al.(2006)studied the deposition of anticorrosive Zn-AMP thin film

formation through SEM analysis in comparison with “bare” iron metal surface. He also discussed similar morphological structure was observed with Zn-AMP thin films[17].S.Rajendran et al.(2011) discussed the SEM micrographs of carbon steel in well water showed the roughness but the SEM micrographs of the same metal immersed in well water containing 50ppm of Trisodium citrate(TSC), 25 ppm of Zn2+ and 1ml of garlic extract creates a thin protective film, which inhibits carbon steel dissolution[18]. S. Fajardo et al.(2011) observed the smooth surface for low-nickel SS after 15 days of immersion in Ca(OH)2 saturated solution and clearly detected the micropitsafter exposure to 3% NaCl solution[19].S.B.Farina et al observed the continuous and uniform layer of corrosion products without chloride content of about 80µm in depth. On the otherhand a non-uniform layer of corrosion products observed , which grooves between the substrate (Zn) and the corrosion products[20]. 6. Results and Discussion SEM provides a pictorial representation of the surface, the nature of the surface film of corrosion of rebar steel specimen immersed in the SCPS for 3 days in the absence and presence of National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India


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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama inhibitor systems such asSodiummolybdates(SM), trisodiumcitrate(TSC), trisodiumphosphate(TSP), sodium potassium tartrate(SPT) and potassium dichromate(PD)are shown in Fig.2.a, 2.b,2.c,2.d,2.e and 2.f.

Fig.2.a. SEM Micrograph of Rebar Steel

Fig.2.b. SEM Micrograph of Rebar Steel in SCPS containing SM (250ppm)+Zn2+(50ppm)

in SCPS

Fig.2.c. SEM Micrograph of Rebar Steel 2+

Fig.2.d. SEM Micrograph of Rebar Steel

in SCPS containing TSC(250ppm)+Zn (50ppm)

in SCPS containing TSP (250ppm)+Zn2+(50ppm)

Fig.2.e. SEM Micrograph of Rebar Steel

Fig.2.f. SEM Micrograph of Rebar Steel

2+

in SCPS containing SPT(250ppm)+Zn (50ppm)

in SCPS containing PD(250ppm)+Zn2+(50ppm)

National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India


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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama The SEM Micrographs of rebar steel surface immersed in SCPS shown in Fig.2.a, shows the roughness of the metal surface whereas the roughness is reduced in the rebar Steel immersed in SCPS containing the inhibitors (such as SM, TSC, TSP, SPT, PD) 250ppm+Zn2+(50ppm)whichcreates a thin protective film, and it inhibits the rebar steel corrosion which are shown in Fig. 2.b,2.c,2.d,2.e and 2.f. Conclusion The SEM Micrographs of rebar steel surface immersed in SCPS containing the inhibitors (such as SM, TSC, TSP, SPT, PD) 250ppm+Zn2+(50ppm)shows deposition of anticorrosive Zn-inhibitor thin film formationwhich inhibits the rebar steel corrosion.

Thus it is concluded that,SEM analysis is a

powerful characterization technique for studying various metal surfaces for identifying the nature of inhibitor and the protective film formation. References 1. S. Ahmad,Cement Concrete Comp., 2003, 25,459. 2. M.V. Biezma and J.R, San Cristobal,CorrosEngSci Technol., 2005,40,344 3. K.Thangavel,Corros Rev., 2004, 22, 55. 4. M.Moreno, W. Morris, M.G. Alvarez and G.S. Duffo, Corros Sci., 2004, 46(11), 2681-2699. 5. V. Kumar,Corros Rev., 1998, 16, 317. 6. M.Maslehuddin, M.m.Al-ZahraniM.Ibrahim, M.H. Al-Mehthel and S.H. Al-Idi,Constu Build Mater, 2007, 21(8), 1825-1832. 7. R.G.Du, G.G.Hu, R.S.Huang and C.J.Lin,Anal Chem.,2006,78(9), 3179-3185. 8. Huet B,V. L’Hostis, F. Miserque and H. Idrissi,ElectrochemActa, 2005, 51(1), 172-180 9. C.Alonso, M.Castellote and C.Andrade, ElectrochimActa, 2002, 47(21), 3469-3481. 10. O. Poupard, A.Ait-Mokhtar and P.Dumargue, Cement Concrete Res., 2004,34, 991-1000 11. G.S.Duffo, W.Morris, I. Raspini and C.Saragovi,Corros Sci., 2004,46,2143 12. W.C.Yeih and J.Chang, JConstru Build Mater., 2005, 19,516. 13. J. García, F.Almeraya, C. Barrios,C.Gaona, R.Núñez, I. López, et al. Effect ofcathodic protection on steel–concrete bond strength using ion migrationmeasurements. CemConcr Compos 2012;34(2):242–7. National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India


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“SEM AS SURFACE ANALYSIS TOOL” S. Devi Meenakshi, SusaiRajendran and J.Sathiyabama 14. A.D.Portanguen, W. Prince, T. Lutz, G. Arliguie.Detection or quantitative analysisof a corrosion inhibitor, the sodium monofluorophosphate, in concrete. CemConcr Compos 2005;27(6):679–87 15. P. R. Roberge,Handbook of corrosion engineering, New York: McGraw Hill Hand‐book, 1999 16. V. Gentil, Corrosão, 4ª ed., Rio de Janeiro: LTC, 2003. 17. D. DemadisKonstantinos, Chris Mantzaridis and PanagiotisLykoudis,Ind.Eng. Chem. Res. 2006, 45,7795-7800. 18. B.Shyamala Devi, S.Rajendran,International Jour.ofChem.Sci and Tech.,2011,pp.79-87. 19. S.Fajardo, D.M.Bastidas, M.Criado, M. Romero and J.M.Bastidas, Cons.and Build. Mater.,25 (2011), 4190-4196 20. S.B.Farina, G.S. Duffo,ElectrochimActa, 2007, 52(2007),5131-5139.

Received-7-09-2016 Accepted-12-09-2016

National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj

Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan 1, Susai Rajendran 2*, J.Sathiyabama 3, and D.Sathiyaraj 1 1. SKV Higher Secondary School, Kandampalayam-637201, India. Email: [email protected] and [email protected] 2. Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul 624 005,Tamil Nadu, India. Email: [email protected] 3. PG and Research Department of Chemistry, GTN Arts College, Dindigul – 624005, Tamil Nadu, India, Email: [email protected] Abstract The corrosion resistance of Ni-Ti super elastic shape memory alloy and 18 Karat Gold alloy in artificial saliva in presence of Limcee 500mg tablet has been evaluated by polarization study. The corrosion resistance of Ni-Ti super elastic shape memory alloy in artificial saliva in presence of Limcee 500mg tablet increases. Similarly, The corrosion resistance of 18 Karat Gold alloy in artificial saliva in presence of Limcee 500mg tablet increases. The outcome of the study is that people having orthodontic wires made of Ni-Ti Super elastic shape memory alloy and also 18 Karat Gold alloy need not hesitate to take Limcee 500mg tablet. The active ingredients of the tablets have not corroded the orthodontic wires made of Ni-Ti Super elastic shape memory Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.

Int J Nano Corr Sci and Engg 3(4)(2016) 9-27 Editors: Dr S Rajendran, A Christy Catherine Mary

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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj alloy and 18 Karat Gold alloy; rather they have protected the wires by formation of protective film on the surface of the wires.

Keywords: corrosion resistance, Ni-Ti super elastic shape memory alloy, 18 Karat Gold alloy, artificial saliva, Limcee 500mg, polarization study.

1.Introduction Metallic materials are used as implants in dentistry, in reconstructive oral surgery to replace a single tooth or an array of teeth, or in the fabrication of dental prostheses such as metal plates for complete and partial dentures crowns, and bridges. Corrosion of metallic implants is of vital importance, because it can adversely affect the mechanical integrity and bio-compatibility of implants. Many metals and alloys have been used in dentistry as orthodontic wires. Their corrosion behavior in artificial saliva has been investigated by several researchers. The influence of pH and corrosion inhibitors such as citric acid, sodium nitrate, and benzotriazole on the tribo corrosion of titanium in artificial saliva has been investigated [1]. Mareci et al., have investigated the corrosion resistance of five non-precious Ni-Co based alloys in artificial saliva [2]. Kinani and Chtaini have studied the effect of different concentrations of eugenol in artificial saliva on titanium corrosion. [3]. Ziebowicz et.al. Have investigated the corrosion resistance of the commercial metallic orthodontic wires in a simulated intra-oral environment. [4]. The results of corrosion resistance tests of the CrNi, NiTi, and CuNiTi wires showed comparable data of parameters obtained in artificial saliva. The effects of multilayered Ti/TiN or single-layered TiN films deposited by pulse-biased arc ion plating (PBAIP) on the Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj corrosion behavior of NiTi orthodontic brackets in artificial saliva have been investigated by Liu et al. [5].

The corrosion of palladium silver binary alloy [6], dental amalgam [7,8], titanium and titanium alloy [9], and metallic biomaterials (CrNi, NiTi, CuNiTi) [10] in artificial saliva has been investigated. The corrosion behavior of metals in artificial saliva in the presence of compound iodine glycerin [11] and copper ion and aroma compounds [12] has been evaluated.The corrosion resistance of SS316L, mild steel (MS), and mild steel coated with zinc (MS-Zn) has been evaluated in artificial saliva in the absence and presence of spirulina. Potentiodynamic polarization study and AC impedance spectra have been used to investigate the corrosion behavior. The corrosion resistance of these materials in artificial saliva, in the following order: SS 316L > MS-Zn > MS [13]. Rajendran et al., have evaluated the corrosion resistance of three metallic materials, namely, SS 316L, mild steel (MS), and mild steel coated with zinc (MS-Zn) has been evaluated in artificial saliva in the absence and presence of D-Glucose. A potentiodynamic polarization study and AC impedance spectra have been used to investigate the corrosion behavior of these metals. The corrosion resistance of these materials in artificial saliva, in the absence as well as in the presence of D-Glucose, Corrosion resistance increased in the following order: SS 316L > MS-Zn > MS [14]. Corrosion resistance of three metals namely, SS 316L, mild steel (MS) and mild steel coated with zinc (MS-Zn) has been evaluated in artificial saliva in the absence and presence of Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj electrol. The order of corrosion resistance of metals in artificial saliva, in the absence and also in the presence of electrode was SS 316L > MS > MS-Zn [15]. Rajendran et al., have evaluated the corrosion resistance of three metals namely, SS 316L, mild steel (MS) and mild steel coated with zinc (MS-Zn) in artificial saliva in the absence and presence of spirulina. The order of corrosion resistance of metals in artificial saliva, was SS 316L > MS > MS-Zn [16]. The present work is undertaken to investigate the corrosion resistance of orthodontic wire made of Ni-Ti super elastic shape memory alloy and 18 karat gold alloy in artificial saliva in the absence and presence of Limcee500mg tablet orally taken in. Electrochemical studies such as polarization study used. 2.Methods and materials 2.1 Preparation of Artificial saliva solution Artificial saliva is prepared in laboratory and the composition of artificial saliva is as follows: KCl - 0.4 g/lit, NaCl - 0.4 g/lit, CaCl2.2H2O - 0.906 g/lit, NaH2PO4.2H2O -

0.690 g/lit,

Na2S.9H2O -0.005 g/lit, Urea – 1 g/lit. The composition of tablets B, is given in Table :1 Table: 1 Composition of Tablets B

Tablet names

LIMCEE

Composition

1.Ascorbic acid -100mg

Represented by

TABLET-B



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj 500mg(VITAMIN C

2.Sodium Ascorbate-450 mg

CHEWABLE )

2.2 Potentiodynamic Polarization Polarization studies were carried out in a CHI- electrochemical work station with impedance model 660A. It was provided with iR compensation facility. A three electrode cell assembly was used is shown in scheme 1. The working electrode was carbon steel. A SCE was the reference electrode. Platinum was the counter electrode. From polarisation study, corrosion parameters such as corrosion potential (Ecorr),corrosion current (Icorr),Tafel slopes anodic = ba and cathodic = bc were calculated and polarization study was done. The scan rate (V/S) was 0.01. Hold time at (Efcs) was zero and quiet time (s) was two.

Scheme 1: Three electrode cell assembly Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj 3.RESULTS AND DISCUSSION

Influence of Limcee 500mg Tablet on the corrosion resistance of Ni-Ti Super elastic shape memory alloy and also 18 karat gold alloy immersed in Artificial Saliva (AS) has been investigated by Polarization study (i) Ni-Ti Super elastic shape memory alloy- Limcee 500mg Tablet system Influence of Limcee 500mg Tablet on the corrosion resistance of Ni-Ti Super elastic shape memory alloy immersed in Artificial Saliva (AS) has been investigated by Polarization study 3.1 Analysis of potentiodynamic polarization curves Electrochemical studies such as polarization study have been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process [18-25]. If a protective film is formed on the metal surface, the corrosion current value (Icorr) decreases. The potentiodynamic polarization curves of of Ni-Ti Super elastic shape memory alloy

immersed in Artificial Saliva (AS) in the absence and presence of Limcee

500mg tablet, obtained from polarization study are shown in Fig-2.The corrosion parameters , namely, corrosion potential (Ecorr mV vs SCE), Tafel slopes (bc mV/decade; ba mV/decade) , linear polarization resistance( LPR ohm cm2 ), and corrosion current (Icorr A/cm2 ) values are given in Table 2.



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj Table 2: Corrosion parameters of Ni-Ti Super elastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of Limcee 500mg, obtained from polarization study

System

AS AS + Tablet B (300 ppm)

Ecorr

bc

ba

mV vs SCE

mV/

mV/

decade

decade

-521

205

-478

209

LPR

Icorr

ohm cm2

A/cm2

249

419028

11.68 x 10-8

287

548343

9.619 x 10-8



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj Fig 2: Polarization curves of Ni-Ti Super elastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of Limcee 500mg Tablet (a) Artificial Saliva (AS); (b) AS +Limcee 500mg Tablet (300 ppm)

When Ni-Ti Super elastic shape memory alloy immersed in Artificial Saliva (AS),the corrosion potential is -521 mV vs SCE. When Limcee 500mg Tablet (300 ppm) is added to the above system the corrosion potential is shifted to the anodic side (-478 mV vs SCE). This indicates that the anodic reaction is controlled predominantly. That is the anodic reaction of metal dissolution is controlled by formation of a protective film on the anodic sites of the metal surface. The active ingredients of the tablet have been adsorbed on the metal surface forming metal complexes on the anodic sites. Further, the LPR value increases from 419028 ohmcm2 to 548343 ohmcm2; the corrosion current decreases from 11.68 x 10-8 A/cm2 to 9.619 x 10-8 A/cm2.Hence, polarization study confirms the formation of a protective film on the metal surface. All these observations lead to the conclusion that in presence of Limcee 500mg Tablet (300 ppm) the corrosion resistance of Ni-Ti Super elastic shape memory alloy increases. Hence polarization study leads to the conclusion that people having orthodontic wires made of Ni-Ti Super elastic shape memory alloy need not hesitate to take Limcee 500mg Tablet . The active ingredients of the tablets have not corroded the orthodontic wires made of Ni-Ti Super elastic shape memory alloy; rather they have protected the wire by formation of protective film on the surface of the wires.



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj 4.Conclusion Results of the polarization study leads to the conclusion that in presence of Limcee 500mg Tablet (300 ppm) the corrosion resistance of Ni-Ti Super elastic shape memory alloy in contact with artificial saliva increases. Implication The outcome of the study is that people having orthodontic wires made of Ni-Ti Super elastic shape memory alloy need not hesitate to take Limcee 500mg Tablet. The active ingredients of the tablets have not corroded the orthodontic wires made of Ni-Ti Super elastic shape memory alloy; rather they have protected the wire by formation of protective film on the surface of the wires.

(ii). 18 karat gold alloy- Limcee 500mg Tablet system Influence of Limcee 500mg Tablet on the corrosion resistance of 18 karat gold alloy immersed in Artificial Saliva (AS) has been investigated by Polarization study Analysis of potentiodynamic polarization curves Electrochemical studies such as polarization study have been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process [18-25]. If a protective film is formed on the metal surface, the corrosion current value (Icorr) decreases. The potentiodynamic polarization curves of of 18 karat gold alloy immersed in Artificial Saliva (AS) in the absence and presence of Limcee 500mg tablet, obtained from polarization study are shown in Fig-3.The corrosion parameters , namely, corrosion potential (Ecorr mV vs SCE), Tafel slopes (bc

mV/decade;

ba mV/decade) , linear polarization

resistance( LPR ohm cm2 ), and corrosion current (Icorr A/cm2 ) values are given in Table 3. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj Table 3: Corrosion parameters of 18 karat gold alloy immersed in Artificial Saliva (AS) in the absence and presence of Limcee 500mg Tablet , obtained from polarization study Ecorr

bc

ba

mV vs SCE

mV/

mV/

decade

decade

AS

-295

188

AS + Tablet B (300 ppm)

-323

174

System

LPR

Icorr

ohm cm2

A/cm2

250

635102

7.332 x 10-8

245

667347

6.626 x 10-8



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj Fig 3: Polarization curves of 18 karat gold alloy immersed in Artificial Saliva (AS) in the absence and presence of Limcee 500mg Tablet (a) Artificial Saliva (AS) ; (b) AS +Limcee 500mg Tablet (300 ppm)

When 18 karat gold alloy immersed in Artificial Saliva (AS),the corrosion potential is -295 mV vs SCE. When Limcee 500mg Tablet (300 ppm) is added to the above system the corrosion potential is shifted to the cathodic side (-323 mV vs SCE). This indicates that the cathodic reaction is controlled predominantly. That is the cathodic reaction of metal dissolution is controlled by formation of a protective film on the cathodic sites of the metal surface. The active ingredients of the tablet have been adsorbed on the metal surface forming metal complexes on the cathodic sites. Further, the LPR value increases from

635102 ohmcm2 to 667347 ohmcm2; the

corrosion current decreases from 7.332 x 10-8 A/cm2 to 6.626 x 10-8 A/cm2.Hence, polarization study confirms the formation of a protective film on the metal surface. All these observations lead to the conclusion that in presence of Limcee 500mg Tablet (300 ppm) the corrosion resistance of 18 karat gold alloy increases. Hence polarization study leads to the conclusion that people having orthodontic wires made of 18 karat gold alloy need not hesitate to take Limcee 500mg Tablet. The active ingredients of the tablets have not corroded the orthodontic wires made of 18 karat gold alloy; rather they have protected the wire by formation of protective film on the surface of the wires.



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj 4.1Conclusion Results of the polarization study leads to the conclusion that in presence of Limcee 500mg tablet (300 ppm) the corrosion resistance of 18 karat alloy in contact with artificial saliva increases. Implication The outcome of the study is that people having orthodontic wires made of 18 karat gold alloy need not hesitate to take Limcee 500mg tablet. The active ingredients of the tablets have not corroded the orthodontic wires made of 18 karat gold alloy; rather they have protected the wire by formation of protective film on the surface of the wires.



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Hence for Limcee 500mg Tablet , 18 K gold is a better Candidate than Ni-Ti alloy

5 References [1] A. C. Vieira, A. R. Ribeiro, L. A. Rocha, and J. P. Celis, “Influence of pH and Corrosion Inhibitors on the Tribocorrosion of Titanium in Artificial Saliva”, WEAR, 261(2006), pp. 994–1001. [2] D. Mareci, Nemtoi Gh, N. Aelenei, and C. Bocanu, “The Electrochemical Behavior of Various Non-Precious Ni and Co Based Alloys in Artificial Saliva”, European Cells and Materials, 10 (2005), pp.1–7. [3] L. Kinani and A. Chtaini, “Corrosion Inhibition of Titanium in Artificial Saliva Containing Fluoride”, LeonardoJournal of Sciences, 11(2007), pp. 3340. [4] A. Ziebowicz, W. Walke, A. Barucha-Kepka, and M. Kiel, “Corrosion Behavior of Metallic Biomaterials Used as Orthodontic Wires”, Journal of Achievements in Materials and Manufacturing Engineering, 27(2008), pp. 151–154. [5] Chenglong Liu, K. Paul Chu, Guoqiang Lin, and Dazhi Yang, “Effects of Ti/TiN Multilayer on Corrosion Resistance of Nickel-Titanium Orthodontic Brackets in Artificial Saliva”, Corrosion Science, 49(2007), pp. 3783–3796. [6] L. Joska, M. Marek, and J. Leitner, “The Mechanism of Corrosion of Palladium–Silver Binary Alloys in Artificial Saliva”, Biomaterials, 26(2005), pp. 1605–1611.



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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj [7] M. A. Christopher Brett and Florin Trandafir, “The Corrosion of Dental Amalgam in Artificial Salivas: An Electrochemical Impedance Study”, Journal of Electroanalytical Chemistry, 52 (2004), pp. 347–354. [8] M. A. Christoper Brett, Iulia Ioanitescu, and Florin Trandafir, “Influence of the Biological Fluid on the Corrosion of Dental Amalgam”, Corrosion Science, 46(2004), pp. 2803–2816. [9] V. Raman, S. Tamilselvi, S. Nanjundan, and N. Rajendran, “Electrochemical Behavior of Titanium and Titanium Alloy in Artificial Saliva”, Trends Biomater. Artif. Organs, 18(2005), pp. 137–140. [10] A. Ziebowicz, W. Walke, A. Barucha-Kepka, and M. Kiel, “Corrosion Behavior of Metallic Biomaterials Used as Orthodontic Wires”, Journal of Achievements in Materials and Manufacturing Engineering, 27(2008), pp. 151–154. [11] Fumiyo Kusu, Keiji Ohe, and Kiyoko Takamura, “Surface Corrosion of Precious Dental Alloys Caused by Compound Iodine Glycerin in Artificial Saliva”, Electrochimica Acta, 43(1998), pp. 1873–1879. [12] J. H. Hong, S. E. Duncan, A. M. Dietrich, and S. F. O’Keefe, “Effect of Copper on the Volatility of Aroma Compounds in a Model Mouth System”, J. Agricultural and Food Chem., 54(2006), pp. 9168–9175. [13] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari, and M. Manivannan, “Corrosion Behavior of Metals in Artificial Saliva in Presence of Spirulina Powder”, Journal of Dentistry and Oral Hygiene, 1(2009), pp. 1–8. [14] S. Rajendran,V. Uma, A. Krishnaveni, J. Jeyasundari, B.Shyamaladevi and M.Manivannan, “Corrosion behaviour of metals in artifical saliva in presence of D- Glucose”. The Arabian Journal for Science and Engineering, Vol. 34(2c), 2009, pp.47-158. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj [15] S. Rajendran, P. Chitra Devi, S. John Mary, A. Krishnaveni, S. Kanchana, R. Nagalakshmi and B. Narayanasamy, “Corrosion behaviour of SS 316L in artificial saliva in presence of electral”. Zastita Materijala, Vol.51, 2010, pp.149-158. [16] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari and M. Manivannan “Corrosion behaviour of metals in artificial saliva in presence of spirulina powder”. , Journal of Dentistry And Oral Hygiene, Vol.1(1),2009, pp1-8. [17] Kang, T., Huang, S.-Y., Huang, J.-J., (...), Diao, D.-F., Duan, Y.-Z. "The effects of diamond-like carbon films on fretting wear behavior of orthodontic archwire-bracket contacts”, Journal of Nanoscience and Nanotechnology, 15(6), A85 (2015) pp.4641-4647. [18] H.Mohamed Kasim Sheit , Susai Rajendran , M.Seeni Mubarak , A Anandan and D. Renita . “Influence of Ciprofloxacin on Corrosion Resistance of SS 316 L immersed in Artificial Saliva” Int J Nano Corr Sci and Engg 3(2) (2016) 1-18. [19] R.Epshiba, A.Peter Pascal Regis and S.Rajendran, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 1-11. [20] N. Kavitha and P. Manjula , Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 31-38. [21] R. Nagalakshmi , L. Nagarajan , R.Joseph Rathish , S. Santhana Prabha , N. Vijaya , J. Jeyasundari and S. Rajendran , Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 39-49. [22] J. Angelin Thangakani, S. Rajendran ,J. Sathiabama , R M Joany , R Joseph Rathis , S Santhana Prabha , Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 50-62. [23] A. Nithya , P.Shanthy, N.Vijaya, R.Joseph Rathish, S.Santhana Prabha, RM Joany and S. Rajendran, Int. J. Nano Corr. Sci. Engg. 2(1) (2015)1-11. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Of Ni-Ti Super Elastic Shape Memory Alloy And 18 Karat Gold Alloy In Artificial Saliva In Presence Of Tablet Limcee 500mg A.Anandan , Susai Rajendran , J.Sathiyabama , and D.Sathiyaraj [24] T.Gowrani , P.Manjula , Nirmala Baby, K.N.Manonmani, R.Sudha[, T.Vennila, Int. J. Nano. Corr. Sci. Engg. 2(1) (2015)12-21. [25] Namita K. Johar, K. Bhrara, R.Epshiba and G. Singh, Int. J. Nano Corr. Sci. Engg. 2(1) (2015)22-31.




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Cyclic Voltammetric Study of Protective Film Formed By Tri Sodiumcitrate In Simulated Concrete Pore Solution on Mild Steel. A.Suriyaprabha, J. Sathiyabama and S. Rajendran

Cyclic Voltammetric Study Of Protective Film Formed By Tri Sodiumcitrate In Simulated Concrete Pore Solution On Mild Steel A.Suriyaprabha[a], J. Sathiyabama[b] and S. Rajendran[c] [a]* Department of Chemistry, Mount Zion college of Engineering and Technology,Pudukkottai622507, Tamil Nadu, India.Email:[email protected] [b] PG and Research Department of Chemistry, GTN Arts College, Dindigul – 624005, Tamil Nadu,India. [c] Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul 624 005,Tamil Nadu, India. Email: [email protected] Abstract The inhibition efficiency of an aqueous solution of Tri Sodium Citrate (TSC) in controlling corrosion of mild steel immersed in DD water with or without the presence of chloride ion has been evaluated by a weight loss method. 200 ppm of TSC offers 98% corrosion inhibition efficiency in the absence of chloride system. Polarization study reveals that an aqueous solution Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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of Simulated Concrete Pore Solution and TSC system controls the cathodic reaction predominantly. Surface evaluation techniques like FTIR is used to determine the nature of the protective film formed on the metal surface. The protective film consists of Fe2+-TSC complex. The cyclic voltammetry study reveals that the protective film is more compact and stable even in 3.5%NaCl environment. Keywords: Simulated concrete pore solution; mild steel; corrosion inhibition; TSC (Tri Sodium Citrate); FTIR; cyclic voltammetry; 1. Introduction Corrosion is a naturally occurring phenomenon which deteriorates a metallic material or its properties because of a reaction with its environment. Corrosion can cause dangerous and expensive damage to everything from pipelines, bridges, and public buildings to vehicles, water, and wastewater systems, and even home appliances. It is one of the most serious problems in the oil and gas industry. Unfortunately, many common corrosion inhibitors are highly toxic and health-hazardable, such as chromate [1], nitrite [2] and aromatic heterocyclic compounds [3] etc. Therefore, it is better to look for environmentally safe inhibitors [4-6]. The use of organic inhibitors is one of the most widely practical methods for protectionof metals and alloys against corrosion. Corrosion inhibitor is a chemical substance which, when added to the corrosive environment at an optimum concentration, there is a decrease in the corrosion rate of metals (or) alloys significantly. The present study is undertaken to investigate the corrosion of mild steel in SCPS prepared in double distilled water in presence of TSC.A saturated solution of calcium hydroxide is used as an SCP solution [7-13]. Potentiodynamic polarization study has been used to evaluate the corrosion resistance of mild steel.To analyze the protective film by FTIR spectra. Cyclic Voltammetry reveals that the protective film is more compact.



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2. Materials and Methods 2.1 Metal specimens TheMild steel specimen was used in the present study. (Composition (wt. %): 0.026 S, 0.06 P, 0.4 Mn, and 0.1 C and balance iron). 2.2 Preparation of the specimens Carbon steel specimens (0.026%P, 0.4%Mn, 0.1 % C and rest iron) of the dimensions 1.0 x 4.0x 0.2 cmwere polished to a mirror finish, degreased with trichloroethylene, and used for the weight-loss method. The molecular structure of trisodium citrate is shown in Scheme1.

Scheme1. Structure of Trisodium citrate 2.3 Simulated Concrete Pore (SCP) Solution A saturated calcium hydroxide solution is used in the present study, as SCP solution. The electrodes made of mildsteel wire were immersed in the SCPS solution, polarization study, CV and FTIRwerecarried out.



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2.4 Weight -loss method

-

Carbon steel specimens were immersed in 100ml of a solution containing 60 ppm of Cl and various concentrations of the inhibitor in the presence and absence of Zn2+ for a period of 1 day.The weights of the specimens before and after immersion were determined using a balance, Shimadzu AY62 model. The inhibition efficiency (IE) was then calculated using the equation IE=100[1-(w2/w1)] % Where w1=corrosion rate in absence of the inhibitor; w2= corrosion rate in presence of the inhibitor. 2.5 Potentiodynamic polarization study Polarization studies were carried out in a CHI –Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The three electrode assembly is shown inScheme 2. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic = bc) were calculated.



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Scheme2. Circuit diagram of three-electrode cell assembly 2.6 Cyclic Voltammetry Cyclic voltammograms were recorded in the Versa STAT MC electrochemical system. A threeelectrode cell assembly was used. The working electrode was carbon steel. The exposed surface area was 1 cm2. A saturated calomel electrode (SCE) was used as the reference electrode and a rectangular platinum foil was used as the counter electrode. The Cyclic Voltammetry curves were recorded in the scan range of −1.8 to −1.8 V (SCE) with a scan rate of 20 mVs−1. 2.7 FourierTransform Infrared Spectra (FTIR) The FTIR spectra were recorded in a Perkin-Elmer-1600 spectrophotometer. The film formed on the metal surface was carefully removed and mixed thoroughly with KBr making the pellet. 3 RESULTS AND DISCUSSION 3.1 Analysis of results of weight loss method The inhibition efficiency of SCPS in the absence and presence of NaCl is given in Table1 (Fig 1). The influence of trisodium citrate on the inhibition efficiency is also given in the table. Table 1.Corrosion rate (CR) of mild steel immersed in SCPS prepared in DD water, in the absence and presence of inhibitors, and the inhibition efficiency (IE%) obtained by weight loss method

System

CR mdd

IE%

DD Water SCPS SCPS+ 4000 ppm NaCl SCPS+ TSC(200 ppm) SCPS+ TSC(200 ppm)+NaCl (4000 ppm)

20 2 3.8 0.4 2

90 81 98 91%



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Immersion period: one day, CR=CorrosionRate;IE=Inhibition Efficiency, mdd=milligram per square decimeter per day.

Fig 1: Correlation between corrosion rate and inhibition efficiency It is observed from the table that inthe presence of SCPS the corrosion inhibition efficiency is 90%.When 4000 ppm of NaCl is added to the system, the inhibition efficiency decreases to 81%. This is due to the fact that chloride ion penetrates through the pores of the protect film and attack the metal surface. When 200ppm of TSC is added to the SCPS the inhibitor efficiency increases to 98%.However, when 4000ppm of NaCl is added to the system, the inhibition efficiency decreases from 98% to 91%. This is due to the attack of chloride ion penetrates through the pores of the protective film and attack the metal surface. Thus weight loss study leads to the conclusion that in the presence of chloride ion the inhibition efficiency decreases. In the presence of TSC the inhibition efficiency increases.



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3.2 Analysis of polarization curves Electrochemical studies such as polarization study have been used to detect the formation of protective film on the metal surface [14-16].When a protective film is formed on the metal surface, the linear polarization resistance (LPR) increases and the corrosion current (I corr) decreases. The potentiodynamic polarization curves of carbon steel immersed in TSC is shown in Fig2.The corrosion parameters, namely corrosion potential (Ecorr), Tafel slopes (bc=cathodic ;ba=anodic), linear polarization resistance (LPR) and corrosion current (I corr), are given in Table: 2,when carbon steel is immersed in an SCPS; the corrosion potential is -930 mV.vs SCE. The formulation consisting of 200ppm of TSC shifts the corrosion potential to -831 mV vs SCE. This suggests that the anodic reaction is predominantly controlled. The LPR value increases from 6947.0 ohm cm2 to 14218.1 ohm cm2. This suggests that a protective film is formed on the metal surface. Further the corrosion current decreases from 5.366x10-6A/cm2 to 2.924x10-6 A/cm2. Table 2.Corrosion parameters of mild steel immersed in simulated concrete (saturated calcium hydroxide solution) pore solution obtained by potentiodynamic polarization study

System

ECorr mVvsSCE

bc mV/decade

ba mv/decade

LPR, ohmcm2

Icorr A/cm2

SCPS(blank)

-930

122

288

6947.0

5.366x10-6

SCPS+ -831 TSC(200ppm)

127

388

14218.1

2.924x10-6



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Figure 2. Polarization curves of mild steel immersed in various test Solution (a) SCPS (blank),(b)SCPS +TSC 200 ppm

3.3 Cyclic Voltammetry Cyclic voltammograms have been used to investigate the corrosion behaviour of metals [1720].Deyab and Keera [20] have analyzed the influence of sulphide, sulphate, and bicarbonate anions on the pitting corrosion behavior of carbon steel in formation watercontaining chloride ions by means of cyclic voltammetry technique. According to Deyab and keera [20] the metal dissolution does not take place. The peak due to reduction of pitting corrosion product, namely iron oxide to iron is more or less absent, but a very small peak appears at -1.12V.However the peak due to reduction of corrosion product, iron oxide,[21] appears clearly at 1.133V is shown in Fig.3a. This indicates that the mild steel is immersed in 3.5% NaCl solution, pitting corrosion takes place. The mild steel electrode was immersed in the SCP solution for one day and the protective film is formed on the metal surface. The stability of the film after immersing in 3.5%NaCl solution was tested by Cyclic Voltammetry.CV is shown in Fig.3b.During anodic sweep the peak appears at 500 mv. This is due to dissolution of iron oxide into iron. During cathodic sweep very small Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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peaks appear at- 400 mv and -500 mv. This indicates that the reduction of iron oxide product is less. Pitting corrosion does not take place. This is due to the formation of protective film on the metal surface in the presence of SCPS. Mild steel electrode was immersed in the solution containing SCPS and (200) ppm of TSC, protective film was formed on the metal surface. This electrode was dried and immersed in 3.5% NaCl solution. Cyclic voltommogram was done is shown in Fig.3c. It is very interesting to note that anodic peak is not seen. Similarly cathodic peaks are not seen. This clearly indicates that the protective film is very stable even in 3.5% NaCl solution. The cyclic voltommogram was run for 5 cycles is shown in Fig.3d. Even then the anodic peak and cathodic peaks do not appear. This means that the protective film is very stable.

Figure 3. a) Cyclic voltammogram of mild steel immersed in 3.5%NaCl solution.



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Figure3. b) Cyclic voltammogram of mild steel electrode immersed in SCP solution.

Figure3. c) Cyclic voltammogram of carbon steel electrode after its immersion in SCPS containing 200ppm of TSC.



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Figure 3. d) Cyclic voltammogram of carbon steel electrode after its immersion in SCPS containing 200ppm of TSC for five cycles.

3.5 FTIR Spectra FTIR Spectra have been used to confirm the formation of protective film formed on the metal surface [24, 25]. Thecorrosion resistance of mild steel immersed in SCPS prepared in DD water in the presence and absence of TSC (Fig.4a) has been evaluated by a weight loss method. When 200 ppm of TSC is added to SCPS the corrosion efficiency is 98%.To know the nature of protective film FTIR spectral study has been used. The co stretching frequency of carboxyl group appears at 1593.04 cm-1. The OH- stretching frequency of the carboxyl group appears at 3456.45 nm. The aliphatic CH stretching frequencies appears at 2925.54, 2968.57. Thus the structure of TSC is confirmed by FTIR spectrum. The mid steel specimen was immersed in SCPS solution and 200ppm ofa TSC system for one day. After one day the metal was taken out and dried. A protective film was found on the metal surface. It was scratched and mixed with KBR pellet. The FTIR spectrum of this film is shown in Fig.4b.



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Figure 4.a) FTIR spectra a) SCP solution

Figure 4.b) FTIR spectra b) film formed on themetal surface after immersion in SCPS containing 200ppm of TSC. The C=O stretching frequency has shifted from 1593.04 cm-1 to 1635.89 cm-1. The OH stretching frequency has shifted from 3456.45 cm-1 to 3435.45 cm-1. This confirms that the oxygen atom of carboxyl group has coordinated with Fe2+ resulting in Fe2+- TSC complex.



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The peak at 669.72 cm-1 is due to metal-oxygen bond. The peak at3435.45 cm-1 is due to OH bond. It is inferred that metal hydroxides such as Iron- hydroxide and calcium hydroxide are present on the metal surface. Thus FTIR spectra lead to the conclusion that the protective film consists of Fe2+- TSC complex, Iron hydroxide and calcium hydroxide. 4 CONCLUSIONS The conclusions drawn from the results may be given (1) The inhibition of corrosion of mild steel in DD water has been evaluated in the absence and presence of chloride. (2) Weight-loss method and cyclic Voltammetry have been used for this purpose. (3) The formulation consisting of 2 ml TSC has 98%corrosion inhibition efficiency. (4) TheCyclic voltammetry study reveals that the protective film is more compact and stable even in 3.5% NaCl environment. (5) FTIR study reveals the protective film consists of Fe2+ – TSC complex, Iron hydroxide and calcium hydroxide. 5 ACKNOWLEDGEMENT The Authors are very much thankful to their respective managements. 6 REFERENCES [1] Baral, R.D. Engelken, Environ. Sci. Policy 5 (2002)12. [2] J.M. Gaidis,Cement Concrete Comp. 26 (2004) 181. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[3] E. Stupnisek-Lisac, A. LonearicBozic, I. Cafuk, Corrosion 54 (1998) 713. [4] A.Y. El-Etre,Corrosion Science, 45 (2003) 2485. [5] A.Y. El-Etre, Corrosion Science, 45(1998)1842. [6] H. Ashassi-Sorkhabi, M.R. Majidi and K. Seyyedi, Applied Surface Science, 225 (2004) 176. [7] A. Sahayaraja, S. Rajendran, J.Electrochem.Sci.Eng.2 (2012)91. [8] N. Manimaran, , S. Rajendran, M. Manivannan, , S. Johnmary,Res. J. Chem. Sci. 2(3) (2012) 52. [9] V.Sribharathy, S. Rajendran, Int. J. Adv. Eng. Sci. Technol. 1(1) (2011) 77. [10] M. Anbarasi, C. Rajendran, S. Vijaya, N.Manivannan, M.Shanthi, T. The Open Corros. J. 4 (2011) 40. [11] V. Johnsirani, S. Rajendran, J. Sathiyabama, T.S. Muthumegala, A. Krishnaveni, N. Hajarabeevi.Bulg. Chem. Commun.44 (1) 2012) 41. [12] M. Sangeetha, , S. Rajendran, , J. Sathiyabama, ,A. Krishnaveni, P. Shanthy, N. Manimaran, B. Shyamaladevi, PortugaliaeElectrochimActa. 29(6)(2011) 429. [13]M. Manivannan, Int. J. Adv. Eng. Sci. Technol.3 (2011) 8048. [14] A. Noreen, Benita, S. H., Rajendran, PortugaliaeElectrochim. Acta 28(1) (2010) [15]R. Epshiba, A. Peter Pascal Regis and S. Rajendran, Int. J Nano. Corr. Sci. Engg. 1(1) (2014)1-11. [16] N. Kavitha and P. Manjula, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 31-38. [17] C. A. M Dutra, E. N. Codaro, R. Z. Nakazato, Mater. Sci. Appl, 2012, 3, 348. [18]L. Feng, H. Yang., F. Wang, Electrochim. Acta, 2011, 58, 427. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[19] Li, Y., Kumar, P., Shi, X., Nguyen, T. A., Xiao, Z., Wu, J., Int. J. Electrochem. Sci., 2012, 7, 8151. [20] M. A. Deyab, S.T. Keera., Egypt.J. Petrol., 21(2012), 31. [21] V. K .Guda, in: Proc. 12th Int. Corrosion Cong., Houston, TX, USA, 1993, 19. [22] S. A. M. Refaey, S.S Abd El-Rehim, F.Taha. M.B. Saleh., R.A. Ahmed., Appl. Surf. Sci, 2000,158,190. [23] D.C.W. Kannagara, B.E. Conway, J. Electrochem. Soc.1987, 134. 894. [24] S. Rajendran., K. Anuradha., K. Kavipriya., A. Krishnaveni., J. AngelinThangakani., Eur. Chem. Bull., 2012, 1, 503. [25] S. Rajendran., B.V. Apparao., N. Palaniswamy., V. Periasamy., G. Karthikeyan., Corros. Sci., 2001, 43, 1345.



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Application of AC impedence spectra in corrosion inhibition studies P.Nithya Devi , J.Sathiyabama, S.Rajendran ,R Joseph Rathis and S. Santhana Prabha

Application of AC impedence spectra in corrosion inhibition studies P.Nithya Devi 1, J.Sathiyabama1 , S.Rajendran1,2 R, Joseph Rathis 3and S .Santhana Prabha3 1

PG and Research Department of Chemistry, GTN Arts College, Dindigul-624005, India. Email: [email protected].

2

Department of Chemistry, St Antony’s College of Arts and Sciences for Women, Amala Annai Nagar, Thamaraipadi (Post),Dindigul – 624 005, Tamilnadu, India. Email: [email protected]. 3

PSNS College of Engineering and Technology, Dindigul, India.

Abstract AC impedance is the frequency domain in the ratio of current and voltage. It can also be more accurately described as the ratio of voltage to current for one complex exponential at a specific frequency. From AC impedence studies the corrosion parameters such as change Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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transfer resistance value (Rt), double layer capacitance value (cdl) and Impedance value are measured. It is also known as Electrochemical Impedance Spectroscopy (EIS) and its main advantages are: EIS may be able to distinguish between two or more electrochemical reactions taking place.EIS can identify diffusion-limited reactions, e.g., diffusion through a passive film. EIS provides information on the capacitive behaviour of the system. EIS is an electrochemical technique, which have applications in corrosion, biosensors, battery development, fuel cell development, paint characterization, sensor development, and physical electrochemistry. The present study explains the application of AC impedence spectra in corrosion inhibition studies. Keywords: AC impedance, Electrochemical Impedance Spectroscopy (EIS), passive film, corrosion, biosensors. 1. Introduction Electrochemical impedance spectroscopy (EIS) (sometimes also called AC impedance or dielectric spectroscopy) is an electrochemical technique that surfaced in the late 1960's but did not become extensively studied until the late 1970's and early 1980's when computer controlled laboratory equipment became the norm. Electrochemical Impedance Spectroscopy (EIS) is a non-destructive technique used to track the condition of a coated metal sample as it changes. In EIS, an AC voltage of varying frequency is applied to the sample and a plot of frequency vs. impedance change is traced for analysis. EIS generates quantitative data that relates to the quality of a coating on a metal substrate by studying the nature of change of impedance of the surface coating.



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2. Definition AC impedance is the estimate of opposition a circuit presents to current each time a voltage is applied. In a more quantitative sense, it is the ratio of voltage to current within alternating current. Impedance can be extended to the idea of AC circuit resistance and include both phase and magnitude. It is very important to understand the concept of AC impedance to promote the proper load in electrical circuits, preventing and monitoring non-beneficial electrical activity that could lead to damage, interruption and in some cases, corrosion. 3. Advantages of EIS The information content of EIS is much higher than DC techniques or single frequency measurements; EIS may be able to distinguish between two or more electrochemical reactions taking place;EIS can identify diffusion-limited reactions, e.g., diffusion through a passive film; EIS provides information on the capacitive behaviour of the system; EIS can test components within an assembled device using the device’s own electrodes; EIS is a versatile technique; Non-destructive; High information content; Running EIS is easy; EIS modeling analysis is very powerful;Simplest working model is best;Complex system analysis is possible;User expertise can be helpful. 4. EIS Instrumentation During an impedance measurement, a frequency response analyzer (FRA) is used to impose a small amplitude .The AC voltage and current response of the fuel cell is analyzed by the FRA to determine the resistive, capacitive and inductive behaviour - the impedance of the cell at that particular frequency. Physicochemical processes occurring within the cell – electron & ion transport, gas & solid phase reactant transport, heterogeneous reactions, etc. – Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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have different characteristic time-constants and therefore are exhibited at different AC frequencies. When conducted over a broad range of frequencies, impedance spectroscopy can be used to identify and quantify the impedance associated with these various processes.

Fig 1.CHI – Electrochemical workstation with impedance, Model 660A. 5. Equivalent Circuit diagrams Electrochemical cells can be modelled as a network of passive electrical circuit elements. A network is called an “equivalent circuit”. The EIS response of an equivalent circuit can be calculated and compared to the actual EIS response of the electrochemical cell. Frequency response of Electrical Circuit Elements are shown in figs 2 (a,b,c)

(a)Resistor

(b) Capacitor

Z = R (Ohms)

Z = -j/C (Farads)

0° Phase Shift

-90° Phase Shift

(c) Inductor Z = j L (Henrys) 90° Phase Shift

A real response is in-phase (0°) with the excitation. An imaginary response. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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6. Nyquist plot Nyquist can be obtained from the values derived from the equivalent cricute diagram this plot will usually reach with the plot obtained from the experiment. The Randels cell for Nyquist plot is shown in fig(1).

Fig 2. Nyquist plot

7. Applications of EIS  Electrochemical Impedance Spectroscopy (EIS) is an electrochemical technique with applications in corrosion, biosensors, battery development, fuel cell development, paint characterization, sensor development, and physical electrochemistry.  EIS can even be used to test the freshness of fish! [1] The reason for this popularity is the high information content of EIS. EIS provides a more thorough understanding of an electrochemical system than any other electrochemical technique.



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8. Application of AC impendance in corrosion inhibition studies AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface.[2-7] If a protective film is formed on the metal surface, the charge transfer resistance (Rt) increases double layer capacitance (Cdl) decreases and the impedance log (z/ohm) value increases Okeoma Kelechukwu

et al.,

[8] have studied the Effects of heat treatment on the

electrochemical corrosion behaviour of aluminum alloy AA8011 in 0.1m H2So4 aqueous acid media. The results are shown in fig 3.

Fig 3 .Ac impedance spectra aluminum alloy AA8011 in 0.1m H2So4 aqueous acid media. AA8011specimens in 0.1M H2SO4 solution were taken for this study. There was three specimens were used, one was the unheated control specimen. Second one was the air quenched specimen and the third one was the oven quenched specimen. It is observed from the fig (3) that all the specimens display similar impendence features; each Nyquist plot is Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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characterized by a single depressed capacitive semicircles from high to intermediate frequencies followed by a low frequency inductive arc. The capacitive loop can be attributed to charge transfer processes associated with the effects of the double layer capacitance and its diameter is related to the charge transfer resistance (Rct) at the metal/solution interface, while the inductive loop probably results from the intermediate products. The Nyquist plots clearly indicate that heat treatment caused increase in the diameter of the capacitive arc, hence the Rct which corresponds to an increase in the corrosion resistance of AA8011 in 0.1 M H2SO4 solution. This effect is more pronounced for oven quenched sample and points toward the low corrosion susceptibilities of the heat treated samples in the sulphuric acid medium. Rct increase in the order unheated< air quenched < oven quenched. It is concluded that oven quenched sample is more corrosion resistance than air quenched and unheated samples.

Latifa Kinani and Abdelilah ChtainI [9] have studied corrosion inhibition of titanium in artificial saliva containing fluoride. They observed that when the concentration on eugenol was 0.1 M, the Nyquist plots showed of three-circle corresponding the formation the tridimentionel film on the surface which reduces corrosion. It is shown in fig (4).



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Fig 4. Electrochemical impedance spectroscopy for titanium grade 2 fluoride media at pH2+ (10-1M) engenol. M. Pandiarajan et al., [10] has investigated Corrosion Resistance of Mild Steel in Simulated Concrete Pore Solution. Mild steel has been immersed in SCPS prepared in rain water, well water, sea water. The corrosion resistance of mild steel in various test solution has been evaluated by AC impedance spectra. The impedance spectra are shown in fig (5). The corrosion parameters derived from the spectra are shown in table (1). It is observed that the corrosion resistance of mild steel immersed in SCPS prepared in various water samples namely rain water, well water and sea water is in the following order Rain water > Well water > Sea water.



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Table 1. Impedance parameters of mild steel immersed in simulated concrete pore solution (saturated calcium hydroxide solution), obtained by AC impedance spectra study.

System

Rt Ohm cm2

Cdl

Impedance

F/cm2

(log z/ohm)

1.039x10-6

4.7

51228

9.95x10-7

4.8

825

6.18x10-5

3.37

SCPS prepared in well water

38460

1.32x10-5

4.6

Sea water

83.06

6.14x10-4

2.10

SCPS prepared in sea water

80.48

6.33x10-4

2.09

Rain water SCPS prepared in rain water Well water

49068

When corrosion resistance increases, Charge transfer resistance (Rt) increases and double layer capacitance (Cdl) values decreases are derived from Nyquist plots. Impedance values, log (z/ohm) increases and phase angle values also increases are derived from Bode plots. It is observed that mild steel is more corrosion resistance in SCPS prepared in rain water than in rain water. It is observed from fig 5 that when mild steel was immersed in rainwater two semi circles were observed. This is characteristic of a protective film formed and then broken. The breaking of the film is due to the presence of corrosive ions such as chloride, sulphate and fluoride present in rainwater (Table 1). The equivalent circuit diagram for such system is shown in Scheme 1. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Fig 5.AC Impedance spectrum of mild steel immersed in various test solution (Nyquist plot) a) Rain water b) SCPS prepared in rain water

Scheme 1-Equivalent circuit for a failed coating. Cc - The capacitance of the intact coating, Rpo - pore resistance, Rct - charge transfer resistance, Rs - solution resistance, Cdl - double layer capacitance.



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When mild steel was immersed in SCPS prepared in rainwater the two semi circles disappear and one semicircle appears. This is characteristic of diffusion controlled process. When mild steel was immersed in rainwater two semicircles were obtained one was due to polarization resistance and other was due to pores resistance. From this it is clear that when mild steel was immersed in rainwater a porous inhibitive film was formed. When concrete pore solution was added to rainwater, the two semicircles were disappeared. Only one semicircle with polarization resistance was noticed. This indicates that addition of concrete pore solution to rainwater reduces the porosity of the inhibitor film. The curve obtained is of diffusing control type. This indicates that when concrete pore solution was added, the inhibitor (Saturated calcium hydroxide) diffusion continuously in the pores of the film and on the damaged part of the inhibitor film.

The various ions present in simulated concrete pore solution diffuse towards the metal surface and form a stable protective film formed on the metal surface. Equivalent circuit diagram for such a system is shown in Scheme 2. The circuit models a cell where polarization is due to a combination of kinetic and diffusion process.

Scheme 2



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Rs - Solution resistance, Rct - Charge transfer resistance, W - Warburg diffusion resistance, Cdl - Double layer capacitance .

8.1 EIS Spectra of SCPS water prepared in well water It is observed from the table that mild steel is more corrosion resistance in SCPS prepared in well water than in well water. When mild steel was immersed in well water, the Rt value was 825 ohm cm2. When it was immersed in simulated concrete pore solution prepared in well water, the Rt value tremendously increases from 825 to 38460 ohm cm2. This indicates that a stable protective film is formed on the metal surface in presence of SCPS. This is further supported by the decrease in Cdl value from 6.18x10-5 to 1.326x10-5. The impedance value increases from 3.37 to 4.6. When mild steel was immersed in well water two semi circles were observed. This is characteristic of a corroding system. The equivalent circuit is shown Scheme 1. When mild steel was immersed in SCPS prepared in well water, the Nyquist plot observed is characteristic of a diffusion controlled process (Figures 6 and 7). The enlarged figure of 6 is shown in Figure 7. It reveals that the corrosion process is a diffusion controlled process. The ions present in well water and SCPS diffused towards the metal surface and formed a protective film which is stable.



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Fig 6. AC Impedance spectrum of mild steel immersed in well water (Nyquist plot)

Fig 7.AC Impedance spectrum of mild steel immersed in SCPS prepared in well water (Nyquist plot). Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Fig 8..Enlarged Figure of fig 7.

8.2 EIS Spectra of SCPS water prepared in Sea water It is observed from the table that mild steel is more corrosion resistance in SCPS prepared in Sea water than in Sea water. When mild steel was immersed in seawater, the Rt value is 83.06 ohm cm2. When SCPS was added the Rt value decreases from 83.06 to 80.48 ohm cm2. This indicates that the protective film formed is not stable and the metal undergoes corrosion. This supported by the fact that Cdl value increases from 6.14x10-4 to 6.33x10-4 F/cm2, further the impedance value decreases from 2.10 to2.09. In presence of SCPS, the phase angle value decreases from 54 to 50 degree which is characteristic of a corroding system. The equivalent circuit diagram for the corroding system (Figure 9) is shown in Scheme 3. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Scheme 3. Cdl – Double layer capacitance. Rs – Solution resistance Rct – Charge transfer resistance



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Fig 9. AC Impedance spectra of mild steel immersed in various test solutions (Nyquist plot); a) Seawater. b) SCPS prepared in seawater.

It is observed from the study that the corrosion resistance of mild steel immersed in SCPS prepared in various water samples namely rain water, well water and sea water is in the following order: Rain water>well water>sea water.

8.3 EIS Spectrum of orthodontic wires In Saliva S. Rajendran et al., [11] has investigated Corrosion behaviour of SS 316 L in artificial saliva in presence of electoral. They have employed EIS spectra to investigated the corrosion resistance of three materials. They have observed that the decreases order of corrosion resistance of metals in AS. In the absence and also presence of electoral was SS3161 >MS> MS-Zn. The ESI Spectra are shown in figs the corrosion parameters are given in table 2. 8.4 EIS for MS System It is observed from fig 4 that mild steel is more corrosion resistance in the AS+ electoral system than in AS + MS system. The Nyquist plots are more are less semi-circle .They are characterise of corroding system is shown in fig 10.



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Fig10. AC impedance spectra (Nyquist plots) of MS immersed in various test solutions: a) AS, b) AS + electoral

8.5 EIS for MS-Zn System It is observed from fig 4 that mild steel is more corrosion resistance in the AS+ electoral system than in AS+ MS-Zn system. The Nyquist plots are more are less semi-circle. They are characterise of corroding system is shown in fig 11.



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Fig11. AC impedance spectra (Nyquist plots) of MS -Zn immersed in various test solutions: a) AS, b) AS + electoral.

8.6 EIS for SS316L System It is observed from fig 12 that mild steel is more corrosion resistance in the AS+ electoral system than in AS+ SS316L system. It is observed from the Nyquist plot is entirely different from that of MS system and MS+ Zn system. An enlarged image is in the higher frequency range is also shown in fig (12). It is observed that the process consist of kinetic diffusion control process.



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Fig 12. AC impedance spectra (Nyquist plots) of SS316L immersed in various test solutions: a) AS, b) AS + electoral

Table 2 Corrosion parameters of metals immersed in artificial saliva (AS) in the absence and presence of electoral obtained from AC impedance spectra

Metal

MS

MS-Zn

System

Nyquist plot

Bode plot

Rt

Cdl

Impedance value

ohm cm2

F/cm2

log(z/ohm)

AS

779

6.54 x 10-9

2.92

AS + Electral

847

6.023 x 10-9

3.014

AS

650

7.84 x 10-9

2.82

AS + Electral

564

9.045 x 10-9

2.81



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SS 316L

AS

29577

0.17 x 10-9

4.72

AS + Electral

60090

8.48 x 10-11

4.993

AC impedance spectra has led to the following conclusions In the absence of electral, the order of corrosion resistance was: SS 316L > MS > MS-Zn In the presence of electral, the order of corrosion resistance was SS 316 L > MS > MS –Zn

8.9 EIS spectra of extract of natural products offering corrosion resistance M. Sangeetha et al., [12] investigated the Eco friendly extract of banana peel as corrosion inhibitor for carbon steel in sea water. They evaluated the AC impedance spectra of carbon steel immersed in various test solutions is shown in fig (13). The corrosion parameters are given in table 3. It is observed from fig (13) that the Nyquist plots are semicircle in nature which indicates the characteristics of corroding system. It is inferred that it is not a very good protective system. AC impedance spectra reveal that a protective film is formed on the metal surface.



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Fig 13. AC impedance spectra of carbon steel immersed in various test solutions (Nyquist plots). (a) Sea water(blank) ; (b) BPE (4mL) + Zn2+ 15 ppm. Table 3: Corrosion parameters of carbon steel immersed in Banana peel extract, obtained from AC impedance spectral study. System

Sea water (blank

BPE (4ml) +Zn2+

Nyquist plot

Bode plot

Rt

Cdl

Impedance value

ohm cm2

F/cm2

log(z/ohm)

90.32

5.6465 x10-8

2.011

175.2

5 .9101 x10-8

2.304

(15ppm) Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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10. Conclusion It is concluded that, AC impedance spectra strongly be used in the corrosion studies to know the inhibition efficiency of corrosion inhibitors for various metals and alloys. References [1] J. Niu and J.Y. Lee, A new approach for the determination of fish freshness by electrochemical impedance spectroscopy, (2006 ) 780–785 . [2] Gowrani T., Manjula P., Nirmala Baby C. Manonmani, Sudha K.N., Vennila R. Thermodynamical Analysis of MBTA on the Corrosion Inhibition of Brass In 3 % NaCl Medium. Int. J. Nano. Corr. Sci. Engg., 2015, 2(1), P. 12–21. [3] Namita K., Johar K., Bhrara R., Epshiba R., Singh G. Effect Of Polyethoxyethylene N, N, N‘ 1, 3 Diamino Propane on The Corrosion of Mild Steel In Acidic Solutions. Int. J. Nano Corr. Sci. Engg., 2015, 2(1), P. 22–31. [4] Christy Catherine Mary A., Rajendran S., Hameed Al-Hashem, Joseph Rathish R., Umasankareswari T., Jeyasundari J.Corrosion Resistance Of Mild Steel In Simulated Produced Water In Presence Of Sodium Potassium Tartrate. Int. J. Nano Corr. Sci. Engg., 2015, 2(1), P. 42–50. [5] Sangeetha M.,Rajendran S., Sathiyabama J., Umasankareswari T., Krishnaveni A., Joany R.M., Int. J. Nano. Corr. Sci. Engg, 2015, 2(3), P. 14–21. [6] Nithya Devi P., Sathiyabama J., Rajendran S. Joseph Rathish R., Santhana Prabha S. Influence of citric acid-Zn2+ System on Inhibition of Corrosion of Mild Steel in Simulated Concrete Pore Solution. Int. J. Nano Corr. Sci. Engg., 2015, 2(3), P. 1–13. [7] V.R. Nazeera Banu, S. Rajendran, S. Senthil Kumaran, Investigation of the inhibitive effect of Tween 20 self assembling nanofilms on corrosion of carbon steel

Journal of

Alloys and Compounds, 2016, 675,139. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[8] B.Okeoma Kelechukwu , O.Owate Israel , E.Oguzie Emeka , M.Mejeha Ihebrodike, International Journal of Materials and Chemistry , Effects of Heat Treatment on the Electrochemical Corrosion Behaviour of Aluminum Alloy AA8011 in 0.1M H2SO4 Aqueous Acid Media , 2012, 2(4): 178-184. [9] Latifa KINANI and Abdelilah CHTAINI, Leonardo Journal of Sciences, Corrosion Inhibition of Titanium in Artificial Saliva Containing Fluoride,11, 2007p. 33-40. [10]M. Pandiarajan , P. Prabhakar and S. Rajendran ,corrosion behaviour of mild steel in simulatedconcrete pore solution prepared in rain water, well water and sea water, Eur. Chem. Bull. 2012, 1(7), 238-240. [11] S. Rajendran, P. Chitradevi, S. Johnmary, A. Krishnaveni, S.Kanchana, Lydia Christy, R. Nagalakshmi, B. Narayanasamy, Corrosion Behaviour Of Ss 316 L In Artificial Saliva In Presence of Electral, Zaštita Materijala (2010) 51(3) 149-152. [12] M. Sangeetha , S. Rajendran , J. Sathiyabama and P. Prabhakar, Eco friendly extract of Banana peel as corrosion inhibitor for carbon steel in sea water, J. Nat. Prod. Plant Resour., 2012, 2 (5), 601-61.



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Application off electrochemical studies in corrosion iinhibition off stainless ssteel 18/8 In oil well water using u trisodium citrate as inhibitor 1

K.Nithya and 2M.Suganya

APPLICATION OF ELECTROCHEMICAL STUDIES IN CORROSION INHIBITION OF STAINLESS STEEL 18/8 IN OIL WELL WATER WATER USING

TRISODIUM CITRATE

AS INHIBITOR 1

K.Nithya and 2S.Devi Meenakshi

Department of Chemistry and Physics Nadar Saraswathi College of Arts & Science, Theni. E-mail:[[email protected] and [email protected]] [email protected] ABSTRACT Corrosion resistance behavior of stainless steel 18/8 was evaluated in trisodium risodium citrate in petroleum oil well water concentrations the inhibition efficiency of an aqueous solution of Tri Sodium Citrate (TSC) in controlling corrosion of mild steel immersed in oil water TSC offers. Polarization study reveals als that an aqueous solution of simulated concrete concrete Pore Solution and TSC system controls the cathodic reaction. reaction Tafel and polarization resistance techniques were used to Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 3(4 44-55 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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Application of electrochemical studies in corrosion inhibition of stainless steel 18/8 In oil well water using trisodium citrate as inhibitor 1


estimate the corrosion rate, the polarization resistance and inhibition of the alloy samples. Effective corrosion inhibition was also exhibited on the tested sample. Keywords: Stainless steel 18/8corrosion trisodium citrate, oil well water, polarization, inhibition.

1. Introduction Corrosion is a naturally occurring phenomenon which deteriorates a metallic material or its properties because of a reaction with its environment. Corrosion can cause dangerous and expensive damage to everything from pipelines, bridges, and public buildings to vehicles, water, and wastewater systems, and even home appliances. It is one of the most serious problems in the oil and gas industry. Unfortunately, many common corrosion inhibitors are highly toxic and health-hazardable, such as chromate [1], nitrite [2] and aromatic heterocyclic compounds [3] etc. Therefore, it is better to look for environmentally safe inhibitors [4-6]. The use of organic inhibitors is one of the most widely practical methods for protection of metals and alloys against corrosion. Corrosion inhibitor is a chemical substance which, when added to the corrosive environment at an optimum concentration, there is a decrease in the corrosion rate of metals (or) alloys significantly. In oil and gas production industry, internal corrosion of carbon steel pipeline is a well-known phenomenon and a serious problem, and inhibition is the most cost effective and flexible method of corrosion control. Adsorption of an organic inhibitor on a metal surface are physical or electric charge to the Metal surface forming a coordinate bond. In this experiment I use the metal like stainless steel 18/8.Also known as the Therefore, knowledge of the mechanism of a corrosion inhibition process Therefore, knowledge of the mechanism of a corrosion inhibition Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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process is highly desirable in the design and proper selection of inhibitors. Inhibitors can interfere with the anodic or cathodic reaction, and can form a protective barrier on the metal surface against corrosive agents or can work by a combination of these actions. For application in the petroleum industry, organic inhibitors containing nitrogen (amines) are often used because of their effectiveness and availability. When a corrosion inhibitor is added to a system, adsorption of inhibitor molecules at the metal-solution interface occurs and this is accompanied by a change in potential difference between the metal electrode and the solution due to the nonuniform distribution of electric charges at the interface. Many researchers have been working on the performance and mechanisms of the inhibitors based on the test results in small-scale laboratory systems. The studies of Mansfield (1985) point out that interface inhibition presumes a strong interaction between the corroding substrate and the inhibitor. The two main types of the adsorption of an organic inhibitor on a metal 304 austenite steel and its contains 18% of chromium, 8% of a nickel. Surface is physical or electric charge to the metal surface, forming a coordinate-type bond. It is nonmagnetic steel which cannot be hardened by heat treatment, but instead must be cold worked to obtain higher tensile strengths. The 18% minimum chromium content provides corrosion and oxidation resistance. The alloy's metallurgical characteristics are established primarily by the nickel content (8% mm.), which also extends resistance to corrosion caused by reducing chemicals. Organic inhibitor like trisodium citrate take i did my project.its helpful at medicinal field and it’s have a many properties Trisodium citrate (TSC) is the inorganic compound with the chemical formula C6H5Na2O7 It is a white, granular or crystalline solid, highly soluble in water producing an alkaline solution. Trisodium citrate inhibit a corrosion in petroleum water contains a sodium sulphite and concentrated HCl. Inhibits a pipeline corrosion , Effective corrosion inhibition was also exhibited Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application off electrochemical studies in corrosion iinhibition off stainless ssteel 18/8 In oil well water using u trisodium citrate as inhibitor 1


on the tested sample. Stainless steel also known as a inox steel.

Figure1. Structure of Trisodium citrate 2. MATERIALS AND METHODS Stimulated Petrol Oil Solution A saturated solution of sodium chloride (Nacl) (Nacl) 3.5g was weighed and 0.305g of calcium ca chloride solution (CaCl2) and 0.186g of magnesium chloride (Mgcl2) make 500ml in standard measuring flask (SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution was mixed with a fraction n of a seconds. Evolve the hydrogen sulphide smell ((H2S) to form a petrol oil water. Metal specimens SS 18/8:18% of chromium and 8%of nickel was used in the present study. Potentiometric studies Polarization studies were carried out in i a CHI-Electrical workstation with impendence, Model Mod 660A.A three electrode cell assembly was used. The working electrode was one of the three metals. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study corrosion parameters such as corrosion potential (Ecorr),corrosion current(Icorr) and Tafel slopes (anodic=ba and cathodic=bc)were calculated. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 3(4 44-55 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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3. Experimental 3.1. Sample Preparation Stainless steels are made of some basic elements found in earth iron ore, chromium, Silicon, nickel, carbon, nitrogen and manganese. Properties of the final alloy are tailored by varying the amounts of these elements. It also improves corrosion resistance, which makes it valuble for use in duplex stainless steels. The process of melting, casting, forming, heat treatment, descaling, cutting, finishing the final stainless steel 18/8 will be formed. The stainless steel were mechanically polished by emery paper washed in double distilled water and dried in warm. Trisodium citrate was at one time extensively used in formulations for a variety of consumer grade soaps and detergents, agents. The pH of a 1% solution is 12 it is very basic and the solution is sufficiently alkaline.

3.2 Electrochemical Measurements Electrochemical studies were carried out using conventional three electrode with larger area platinum foil as counter electrode and saturated calomel electrode (SCE)as reference electrode. Electrochemical analyzer (1280B) interfaced with an IBM computer was used for measurements. The polarization studies were made after the specimen attained a steady state potential. The polarization was carried out using a corrware software from a cathodic potential of -0.2V to an anodic potential +0.2V with respect to the corrosion potential at sweep rate of0.5 mV/s. E versus log I curves were plotted. The linear TAFEL segments of the anodic and cathodic curves were extra plotted to corrosion potential to obtain the corrosion current densities. The corrosion inhibition efficiency was evaluated from the measured icorr values using the relationship: IE(%)=icorr-icorr”/Icorr0x100

(1)



48



Where icorr and icorr” are the corrosion current densities without and with the addition of various concentrations of the inhibitor, respectively. For linear polarization measurements a sweep from -0.02 to +0.02V versus open circuit potential at a sweep rate

of 0.5mV/s was used .The

polarization resistance ,Rp,is obtained as the slope of the ””h versus I”” curve at the vicinity of corrosion potential Ecorr.The corrosion inhibition efficiency was evaluated from the measured icorr..This DC method of pertubution yields Rp which includes the solution resistance Rs, The inhibition efficiencies were evaluate from the polarization resistance,Rp values are IE%=Rp”- Rp/ Rp”x100

(2)

Where Rpand Rp” are the polarization resistances without and the addition of inhibitors ,respectively plot software was used for data acquisition and analysis of interfacial impedence.AC signals of 10 mV amplitude and a frequency spectrum from 100 KHz to 0.01Hz was impressed and the Nyquist representations of the impedance data were analyzed with View software. The charge transfer resistance Rct is obtained as the diameter of the semi circle of Nyquist curve .By doing so in this AC method of perturbations, the contributions from the solution resistance are eliminated.The inhibition efficiency was evaluated from the measured charge transfer resistance Rct values as IE%=Rct”-Rct/Rct”x100

(3)

Where Rct and Rct” are the charge transfer resistance values in the absence and presence of inhibitors, respectively .The interfacial double layer capacitance Cdl is obtained from the frequency of the point having maximum imaginary component (i.e.the point corresponding to the top of the semi circle)as Cdl=1/2 fmaxRct

(4)



49



Where “”fmax”” corresponds to the frequency having maximum imaginary component.

4. Results and Discussion 4.1 Potentio dynamic polarization study Polarization studies were carried out in a CHI –Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The three electrode assembly is shown in figure 2. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic = bc) were calculated.

4.2. Potentiodynamic Polarization Studies The potentiodynamic polarization curves of stainless steel in oil water contains 3.5g of NaCl and 0.305g of CaCl2 and 0.186 MgCl2With addition of trisodium phosphate(Na3PO4) extracts affects both anodic anodic dissolution of steel cathodic reduction reactions indicating that the extracts could be classified as mixed type inhibitor. The corrosion kinetic parameters such as corrosion potential(Ecorr),corrosion current density (Icorr),anodic Tafel slope (ba) and cathodic Tafel slope (bc)deduced from the house for oil petrol water are in given Table -1.The values of the stainless steel in blank Ecorr(-152),and presence of Trisodium citrate Ecorr(-252), and the value Icorr in blank (9.133x10-9) and in presence of Trisodium citrate the Icorr value is (1.351x10-8). Then the LPR values are in blank is (4375896) in the presence of trisodium citrate is(2449089).in the mixed inhibitor.



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Figure.1.Stainless steel in blank

Figure.2.Stainless steel in TSC

The EIS technique has been one of the most used methods to report the mechanism of corrosion and corrosion protection of metals and alloys in aggressive media [17-21]. The Nyquist plots obtained for the pipeline steel electrodes at an open-circuit potential after their immersion solutions

4.3.AC Impedence The effect of trisodium phosphate on the behavior of stainless steel in petroleum oil water is presented in the form of Nyquist plots on figure.3. The curves show a similar type of Nyquist plots for stainless steel in the presence of trisodium phosphate. Values of impedance parameters of stainless steel in both media are presented in table.1



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Figure. 3. Stainless steel in blank

Figure.4.stainless steel in TSC

Table.1 Electrochemical Potentiodynamic Polarization Studies of Stainless steel in the presence of trisodium citrate SYSTE M SS 18/8

Ecorr

Bc

-152

SS+TSC

-252

b’c

LPR

Icorr

Ref

Cde

Z

Phase angle

1/5.740 1/5.139 4375896

9.133X10-9

-

3.746

78.24

1/7.191 1/5.946 2449089

1.351X10-8

1933 106.9 =1826.1 7915 0 =7915

-

4.226

73.76

5. Conclusion The results obtained from present study showed that trisodium citrate is a good inhibitor and acted as a mixed-type inhibitor in petroleum oil water.Absorption of stainless steel in trisodium citrate obeys in polarization and electrochemical studies.The presence of trisodium Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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citrate inhibits the corrosion process on the stainless steel.Environmentally acceptable organic

corrosion

inhibitor

was

used

in

the

stainless.

6. Reference: [1] A. J. McMahon and S. Groves, “Corrosion Inhibitor Guidelines, A practical guide to the Selection and deployment of corrosion inhibitors in oil and gas production facilities, Report No ESR.95.ER.050,” (1995). [2] J. W. Palmer, W. Hedges and J. L. Dawson, European Federation of Corrosion, The use of Corrosion Inhibitors in Oil and GasProduction (ECF 39Eds., EuropeanFederation of Corrosion, (2004). [3] I. G. Winning, A. Taylor and M. Ronceray, “Corrosion mitigation - the corrosion engineers options,” in SPE International Conference on Oilfield Corrosion, Aberdeen,( 2010). [4] M. R. Gregg and S. Ramachandran, “Review of corrosion inhibitor developments and testing for oil and gas production systems,” in NACE Corrosion (2004). [5] K. Kowate and K. Takahashi, “Interaction of corrosion inhibitors with corroded steel surface,” in Corrosion 96, Denver, Colorado, (1996). [6] J. Dougherthy and D. Stegman, “The effects of flow on corrosion inhibitor performance,” in Corrosion 96, Denver, Colerado, (1996). [7] R. Hausler, D. Stegman, C. Cruz and D. Tjandroso, “Laboratory studies on flow induced localized corrosion in CO2/H2S environments. III. Chemical corrosion inhibition,” in Corrosion 90, (1990). [8] S. Kapusta, P. Rhodes and S. Silverman, “Inhibitor testing for CO2 environments,” in Corrosion 91, (1991).



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[9] E. Gulbrandsen, S. Nesic, A. Strangeland, T. Burchardt, B. Sundfær, H. SM and S. Skjerve, “Effect of precorrosion on the performance of inhibitors for CO2 corrosion of Carbon steel,” in Corrosion 98, (1998). [10] M. Shen, A. Furman, R. Kharshan and T. Whited, “Development of corrosion inhibitors for preventaion of top of line corrosion (TLC),” in NACE Corrosion, (2013). [11] M. Swidzinski, B. Fu, A. Taggart and W. P. Jespon, “Corrosion inhibition of wet gas Pipelines under high gas and liquid velocities,” in Corrosion (2000). [12] T. Zvandasara, “Influence of hydrodynamics on carbon steel erosion-corrosion and Inhibitor efficiency in simulated oilfield brines,” PhD Thesis, University of Glasgow, (2009). [13] B. Singh and K. Krishnathasan, “Pragmatic effects of flow on corrosion prediction,” in NACE Corrosion 2009, Houston, (2009). [14] A. Crossland, R. Woollam, J. Palmer, G. John, S. Turgoose and J. Vera, “Corrosion inhibitor effieciency limits and key factors,” in Corrosion ( 2011). [15] S. Nesic, “Key issues related to modelling of internal corrosion of oil and gas pipelines - A review,” Corrosion Science, vol. 49, pp. 4308-4338, (2007). [16] P. Bommersbach, C. Alemany-Dumont, J.P. Millet, B. Normand,“Formation and behaviour Study of an environment-friendly corrosion inhibitor by electrochemicalmethods,” Electrochimica Acta, vol. 51, Issue 6, pp. 1076- 1084,(2005). [17]S. Agnesia kanimozhi and S.Rajendran, international journal electrochemicalscience,4(2009) 353 . [18]L. Feng, H. Yang., F. Wang, Electrochim. Acta, (2011), 58, 427. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[19] Li, Y., Kumar, P., Shi, X., Nguyen, T. A., Xiao, Z., Wu, J., Int. J, Electrochem. Sci., (2012), 7, 8151. [20] M. A. Deyab, S.T. Keera., Egypt.J,Petrol., 21(2012), 31. [21] V. K .Guda, in: Proc. 12th Int. Corrosion Cong., Houston, TX, USA, (1993), 19. [22] S. A. M. Refaey, S.S Abd El-Rehim, F.Taha. M.B. Saleh., R.A. Ahmed., Appl. Surf. CaS 2011, 58, 427Li, Y., Kumar, P., Shi, X., Nguyen, T. A., Xiao, Z., Wu, J., Int. J. Electrochem. Sci., (2012),7, 8151. [20] M. A. Deyab, S.T. Keera., Egypt.J. Petrol., 21(2012), 31. [21] V. K .Guda, in Proc. 12th Int. Corrosion Cong., Houston, TX, USA, (1993), 19. [22] S. A. M. Refaey, S.S Abd El-Rehim, F.Taha. M.B. Saleh., R.A. Ahmed., Appl. Surf. [23] B. Shyamaladevi, PortugaliaeElectrochimActa. 29(6)(2011) 429. Eng. Sci. Technol.3 (2011) 8048. [24] A. Noreen, Benita, S. H., Rajendran, PortugaliaeElectrochim. Acta 28(1) (2010). [25]R. Epshiba, A. Peter Pascal Regis and S. Rajendran, Int. J Nano. Corr. Sci. Engg. 1(1) (2014)1-11.




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Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran .

CAN PEOPLE IMPLANTED WITH ORTHODONTIC WIRES MADE OF THERMOACTIVE SUPERELASTIC SHAPE MEMORY ALLOY AND 22 K GOLD TAKE SYZYGIUM CUMINI FRUIT JUICE ORALY? S.Madhumitha 1, V.Priyadharshini 1, A.Sheela 1, C.Aadhithya 1, Dr. M. Sangeetha 2, Dr. S. Rajendran 2 1. Department of Biomedical engineering, RVS School of engineering and Technology, Dindigul – 624005, E-mail: [email protected] [email protected] 2. Department of Chemistry, St.Antony’s College of Arts and Sciences For Women, Women Dindigul – 624005, E-mail: [email protected] [email protected] ABSTRACT Corrosion resistance of two orthodontic wires made of thermoactive superelastic shape memory alloy and 22 K gold in artificial saliva in the absence and presence of syzygium cumini extract has been evaluated by AC impedance spectra. It is observed that in the presence of artificial saliva containing 20 mL fruit extract, the corrosion resistance of thermoactive superelastic shape memory alloy decreases. Henc Hencee people implanted with orthodontic wires made of thermoactive superelastic shape memory alloy should avoid taking the fruit juice. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. (4)(2016) 80 - 87 Int J Nano Corr Sci and Engg 3(4 Editors: Dr S Rajendran, A Christy Catherine Mary

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Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . However interesting the corrosion resistance of 22 K gold increases in presence of artificial saliva containing 20 mL of fruit extract. Hence it implies that people implanted with orthodontic wire made of 22 K gold need not to hesitate to take the fruit juice orally. Keywords:Artificial Saliva, Orthodontic Wires, Thermoactive Superelastic Shape Memory Alloy, 22 K Gold, syzygium cumini 1. INTRODUCTION Our human civilization cannot exist without metals and yet corrosion is their Achilles heel. Corrosion process are responsible for numerous losses mainly in the industrial scope. Considerable efforts are made to find suitable compounds to be used as corrosion inhibitors in various corrosive media. Though many synthetic compounds showed good anticorrosive activity, most of them are highly toxic to both human beings and environment. Extracts of plant materials contain a wide variety of organic compounds. Most of them contain heteroatoms such as P, N, S, O. These atoms coordinate with the corroding metal atom (their ions), through their electrons. Hence protective films are formed on the metal surface and hence corrosion is prevented. They are eco friendly, bio degradable and available in plenty. Recently may researchers doing work on natural inhibitors. Several studies have been published on the use of natural products as corrosion inhibitors. Recently several juice extract are used as corrosion inhibitors for mild steel [1-4], garlic extract is used for aluminium metal [5], ginger [6] and extract of jamun seed for acid medium [7] have been used as corrosion inhibitors. The present work is undertaken to evaluate corrosion resistance of two orthodontic wires made of thermoactive superelastic shape memory alloy and 22 K gold in artificial saliva in the absence and presence of syzygium cumini extract by AC impedance spectra.


Int J Nano Corr Sci and Engg 3(4)(2016) 80 - 87 Editors: Dr S Rajendran, A Christy Catherine Mary

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Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . 2.Methods and materials 2.1 Preparation of Artificial saliva solution Artificial saliva is prepared in laboratory and the composition of artificial saliva is as follows: KCl - 0.4 g/lit, NaCl - 0.4 g/lit, CaCl2.2H2O - 0.906 g/lit, NaH2PO4.2H2O -

0.690 g/lit,

Na2S.9H2O -0.005 g/lit, Urea – 1 g/lit. 2.2 Preparation of syzygium cumini extract An aqueous extract of syzygium cumini (naval fruit) was prepared by adding 10g of syzygium cumini , with distilled water and boiled the water for 15 mins filtering the suspending impurities, and making up to 100 ml. The extract was used as corrosion inhibitor in the present study. 2.3 AC impedance measurements A CHI 660A electrochemical impedance analyzer model was used to record AC impedance measurements. The cell set up was the same as that used for polarization measurements. The real part (Z’) and imaginary part (Z”) of the cell impedance were measured in ohms for various frequencies. The Rt (charge transfer resistance) and Cdl (double layer capacitance) values were calculated. 3.RESULTS AND DISCUSSION 3.1 Analysis of AC Impedance spectra AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface. If a protective film is formed on the metal surface, charge transfer resistance (Rt) increases; double layer capacitance value (Cdl) decreases. Impedance value increases [8-15]. The AC impedance spectra of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained from AC impedance spectra are shown in Fig.1.The AC impedance parameters namely charge transfer resistance (Rt) and double layer capacitance (Cdl) derived from Nyquist plots are Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . given in Table 1. It is observed that when fruit extract is added to artificial saliva, the charge transfer resistance (Rt) decreases from 9695 ohm cm2 to 1709 ohm cm2 for (AS + 10 mL fruit extract) and 9627 ohm cm2 for (AS + 20 mL fruit extract) respectively and the (Cdl ) increases from 6.0856 x 10-10 F/ cm2 to 34.51 x 10-10 F/ cm2 and 6.128 x 10-10 F/ cm2 for (AS + 10 mL fruit extract) (AS + 20 mL fruit extract) respectively. All this observations lead to the conclusion that when we are adding fruit extract to artificial saliva, corrosion resistance of the thermoactive superelastic shape memory alloy is decreased and there is no formation of protective film on the metal surface. Hence people implanted with orthodontic wires made of thermoactive superelastic shape memory alloy should avoid taking the fruit juice.

Fig 1: AC impedance spectra of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract (Nyquist Plots) : (a) Artificial Saliva (AS) ; (b) syzygium cumini fruit extract (c) AS + 10 mL fruit extract (d) AS + 20 mL fruit extract



83

Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . Table .1 AC impedance parameters of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained by AC impedance spectra. System AS Fruit extract AS + 10 mL fruit extract AS + 20 mL fruit extract

Rt ohm cm2 9695 3394

6.0856 x 10-10 17.383 x 10-10

Impedance Log(z/ohm) 1.165 0.521

1709

34.51 x 10-10

1.680

9627

6.128 x 10-10

1.265

Cdl F/ cm2

3.2 Analysis of AC Impedance spectra The AC impedance spectra of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained from AC impedance spectra are shown in Fig.2.The AC impedance parameters namely charge transfer resistance (Rt) and double layer capacitance (Cdl) derived from Nyquist plots are given in Table 2. It is observed that when fruit extract is added to artificial saliva, the charge transfer resistance (Rt) increases from 4262 ohm cm2 to 4657 ohm cm2 for (AS + 10 mL fruit extract) and 5587 ohm cm2 for (AS + 20 mL fruit extract) respectively and the (Cdl ) decreases from 1.384 x 10-9 F/ cm2 to 1.266 x 10-9 F/ cm2 and 1.056 x 10-9 F/ cm2 for (AS + 10 mL fruit extract) (AS + 20 mL fruit extract) respectively. These results lead to the conclusion that a protective film is formed on the metal surface. All these observations lead to the conclusion that in presence of fruit extract the corrosion resistance of 22 K in contact with artificial saliva, increases. Hence AC impedance spectra lead to the conclusion that people having orthodontic wires made of 22 K gold need not hesitate to take syzygium cumini fruit juice. The active ingredients of the juice have not corroded the orthodontic wires made of 22 K Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


84

Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . gold ; rather they have protected the wire by formation of protective film on the surface of the wires.

Fig 1: AC impedance spectra of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract (Nyquist Plots) : (a) Artificial Saliva (AS) ; (b) syzygium cumini fruit extract (c) AS + 10 mL fruit extract (d) AS + 20 mL fruit extract Table .2 AC impedance parameters of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained by AC impedance spectra.

System AS Fruit extract AS + 10 mL fruit extract

Rt ohm cm2 4262 6587

Cdl F/ cm2 1.384 x 10-9 0.895 x 10-9


4657

1.266 x 10-9

1.351



85

Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . AS + 20 mL fruit extract

5587

1.056 x 10-9

1.361

4 Conclusion Results of the AC impedence study lead to the conclusion that  In artificial saliva alone, thermoactive superelastic shape memory alloy is more corrosion resistant than 22K gold.  In fruit juice alone 22 K gold is found to be more corrosion resistant than thermoactive superelastic shape memory alloy.  In presence of artificial saliva containing 10 mL of extract, 22 K gold is found to be more corrosion resistant than thermoactive superelastic shape memory alloy.  The increase in corrosion resistance of the orthodontic wire in presence of fruit extract may be due to the formation of protective film formed on the metal surface due to the adsorbtion of active principle of the ingrediants present in the fruit juice.  People implanted with orthodontic wire made of 22 K gold needs not to hesitate to take the fruit juice orally. 5 References 1. C.A.Loto, A.I.Mohammed, Loto, “Inhibition evaluation of mango juice extracts on the corrosion of mild steel in HCl”. Corrosion Prevention and Control 50(3), (2003), pp.107118. 2. C.A.Loto, A.I.Mohammed, “The effect of cashew juice extract on corrosion inhibition of mild steel in HCl”. Corrosion Prevention and Control 47(2), (2000), pp.50-56. 3. J.C.Da Rocha, J.A.da Cunha Ponciano Gomes, E.D Elia, “Corrosion inhibition of carbon steel in hydrochloric acid solution by fruit peel aqueous extracts”. Corrosion Science 52(7), (2010) pp.2341-2348. 4. P.C.Okafor, E.E.Ebenso, “Inhibitive action of Carica papaya extracts on the corrosion of mild steel in acidic media and their adsorption characterristics”. Pigment and Resin Technology 36(3), (2007), pp.134-140.



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Can People Implanted With Orthodontic Wires Made Of Thermoactive Superelastic Shape Memory Alloy And 22 K Gold Take Syzygium Cumini Fruit Juice Oraly? S.Madhumitha , V.Priyadharshini , A.Sheela , C.Aadhithya , Dr. M. Sangeetha 2, Dr. S. Rajendran . 5. S.L.Priya, A.Chitra, S.Rajenderan, K.Anuradha, “Corrosion behaviour of aluminium in rain water containing garlic extract”. Surface Engineering 21(3), (2005), pp.229-231. 6. A.Bouyanzer, B.Hammouti, “Naturally occurring ginger as corrosion inhibitor for steel in molar hydrochloric acid at 353 K”. Bulletin of Electrochemistry 20(2), (2004), pp.63-65. 7. Ambrish Singh, M. A. Quraishi, “The extract of Jamun (Syzygiumcumini) seed as green corrosion inhibitor for acid media”. Research on Chemical Intermediates 41 (3) , (2015), pp 2901–2914 8. R.Epshiba, A.Peter Pascal Regis and S.Rajendran, Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 1-11. 9. N. Kavitha and P. Manjula , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 31-38. 10. R. Nagalakshmi , L. Nagarajan , R.Joseph Rathish , S. Santhana Prabha , N. Vijaya , J. Jeyasundari and S. Rajendran , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 39-49. 11. J. Angelin Thangakani, S. Rajendran ,J. Sathiabama , R M Joany , R Joseph Rathis , S Santhana Prabha , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 50-62. 12. A. Nithya , P.Shanthy, N.Vijaya, R.Joseph Rathish, S.Santhana Prabha, RM Joany and S. Rajendran, Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 1-11. 13. T.Gowrani , P.Manjula , Nirmala Baby, K.N.Manonmani, R.Sudha, T.Vennila, Int. J. Nano. Corr. Sci. Engg. 2(1), (2015), pp 12-21. 14. Namita K. Johar, K. Bhrara, R.Epshiba and G. Singh, Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 22-31. 15. A.Christy Catherine Mary, S.Rajendran, Hameed Al-Hashem, R.Joseph Rathish, T. Umasankareswari and J Jeyasundari Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 42-50.

Received-14-09-2016 Accepted-19-09-2016 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Comparative parative analysis of corrosion inhibition studies on various m metals in oil well water using trisodium citrate c as inhibitor.

1

M. M.Lavanyaa and2 M.suganya.

COMPARITIVE ANALYSIS OF CORROSION INHIBITION STUDIES ON VARIOUS METALS IN OIL WELL WATER WATER USING TRISODIUM CITRATE AS INHIBITOR 1

M.Lavanyaa Lavanyaa and2 M.suganya.

Department of Chemistry C and Physics Nadar Saraswathi College of Arts & Science, Theni. E-mail:[[email protected] kathirmba27 and [email protected] @gmail.com ABSTRACT The inhibition efficiency of an aqueous aqueou solution of Tri Sodium citrate (TSC) (TSC in controlling corrosion of SS 18/8 immersed in petr200 ppm of TSC offers 98% corrosion inhibition efficiency in the absence of chloride system. Polarization study reveals that an aqueous solution sol of simulated oil well Solution and TSC system controls the cathodic reaction predominantly. The

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 3(4 88 - 103 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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Comparative analysis of corrosion inhibition studies on various metals in oil well water using trisodium citrate as inhibitor.

1

M.Lavanyaa and2 M.suganya. results obtained showed some magnitude of corrosion susceptibility for the stainless steel. Effective corrosion inhibition was also exhibited on the tested sample. Keywords: Simulated oil well water; Stainless steel, galvanized steel, mild steel; corrosion inhibition; TSC (Tri Sodium citrate) electrochemical polarization studies

1. Introduction Facilities for the production of oil and gas often have to cope with corrosive environments. The difficulties in protecting plant become more acute when the facilities are in a hostile and remote offshore setting. Assessment of the potential corrosion for a new facility may lead to the choice of either using corrosion resistant alloys or using carbon steels with corrosion inhibitors.[1-8] For existing, ageing installations, treatment of the produced fluids with corrosion inhibiting chemicals is often the only feasible option. The main mechanisms for internal corrosion of pipelines are aqueous corrosion caused by soluble corrosive gas, such as carbon dioxide, hydrogen sulphide, or oxygen, and corrosion influenced by microorganisms. The oil water can arise from being part of the original reservoir products (formation water) or from water injection used to increase pressure. Corrosion inhibitors work by forming a protective film on the metal preventing corrosive elements contacting the metal surfaces. Then we use the metals like stainless steel 18/8. The term "18-8" is used interchangeably to characterize fittings made of 302, 302HQ, 303, 304, 305, 384, XM7, and other variables of these grades with close chemical compositions. There is little overall difference in corrosion resistance among the "18-8" types, But slight differences in chemical composition do make certain grades more resistant than others Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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1

M.Lavanyaa and2 M.suganya. do against particular chemicals or atmospheres. "18-8" has superior corrosion resistance to 400 series stainless, is generally nonmagnetic, and is harden able only by cold working. And I use mild steel.The use of mild steel as construction material in industrial sectors has become a great challenge for corrosion engineers or scientists nowadays. Most of the acidic industrial applications such as refining crude oil, acid packling , industrial cleaning, acid descaling, and oilwell acid in recovery and petrochemical processes use mild steel as their material. Galvanizing steel also used as the welding industries and I used the inhibitor like trisodium citrate (tsc) used as the cleaning agent, insoluble in ethanol and also attain removes. All the three sample steels are in the petrol oil water contains a sodium chloride (NaCl) 3.5g was weighed and 0.305g of calcium chloride solution (Cacl2) and 0.186g of magnesium chloride (Mgcl2) make 500ml in standard measuring flash (SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution was mixed with a fraction of a second. [9-16] All the samples are exampled in the polarization studies and the electro chemical studies. The expected good reaction will be produced.

2. MATERIALS AND METHODS 2.1 Stimulated Petrol Oil Solution A saturated solution of sodium chloride(NaCl) 3.5g was weighed and 0.305g of calcium chloride solution(Cacl2) and 0.186g of magnesium chloride(Mgcl2) make 500ml in standard measuring flask(SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution



90


1

M.Lavanyaa and2 M.suganya. was mixed with a fraction of seconds. Valve the hydrogen sulphide smell (H2S) to form a petroleum oil water. Made three set of the solutions.[17-30]

2.2 Metal specimens SS 18/8:18% of chromium and 8%of nickel was used and the mild steel, galvanized steel was used.

2.3 Potentiometric studies Polarization studies were carried out in a CHI-Electrical workstation with impedance, Model 660A.A three electrode cell assembly was used. The working electrode was one of the three metals. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current(Icorr) and Tafel slopes (anodic=ba and cathodic=bc)were calculated.[31-37]

2.4 Electro chemical studies A three electrodes cell system containing working electrode (mild steel coupon) of a 1 cm2 exposed area, saturated calomel electrode as a reference and the a platinum electrode as auxiliary were used. All electrochemical experiments were performed at room temperature (25 ± 2°C) in 2M HCl electrolyte solution with and without extracted inhibitor using Gill AC potentiostate manufactured by ACM Instruments. Three different electrochemical tests were conducted, linear polarization resistance (LPR) Potentio dynamic scans (cyclic sweep polarizations, CS) and electrochemical AC impedance spectroscopy (EIS). A linear polarization test was carried out by Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


91


1

M.Lavanyaa and2 M.suganya. a scan from approximately -10mV to +10mV with respect to working electrode rest potential. The cyclic sweep polarization also took in consideration open circuit potentials of working electr and started at a relatively cathodic potential and scanned towards the anodic direction, E = ± 300 mV with a scan rate of 1mV/s. EIS measurements were performed using AC signal amplitude of 20 mV peak to peak in the frequency range of 0.1 Hz to 1kHz. The inhibition efficiency (IE) was determined using the equation IE=(I-Ii)/Ix100………….(1) Where I and Ii are the corrosion current densities without and with inhibitor, respectively.

3. Experimental 3.1. Sample Preparation Stainless steel 18/8mild steel, galvanized steel are made by the superior capacity and the manner of the production I collect that types of the steels.



92


1

M.Lavanyaa and2 M.suganya. Ef=Ri-R0/R0x100………………… (2) Wherever is inhibitor efficiency (percentage), Ri is corrosion rate of metal with inhibitor and Ro is corrosion rate of metal without inhibitor.

3.3 Electrochemical Measurements Electrochemical studies were carried out using conventional three electrodes with larger area platinum foil as counter electrode and saturated calomel electrode (SCE) as reference electrode. Electrochemical analyzer (1280B) interfaced with an IBM computer was used for measurements. The polarization studies were made after the specimen attained a steady state potential. The polarization was carried out using a corer ware software from a cathodic potential of -0.2V to an anodic potential +0.2V with respect to the corrosion potential at sweep rate of0.5 mV/s.E versus log I curves were plotted .The linear TAFEL segments of the anodic and cathodic curves were extra plotted to corrosion potential to obtain the corrosion current densities .The corrosion inhibition efficiency was evaluated from the measured icorr values using the relationship: IE (%) =icorr-icorr”/Icorr0x100 ……..

(3)

Where icorr and icorr” are the corrosion current densities without and with the addition of various concentrations of the inhibitor, respectively .For linear polarization measurements a sweep from0.02 to +0.02V versus open circuit potential at a sweep rate of 0.5mV/s was used. Thepolarization resistance, Rp, is obtained as the slope of the ””h versus I”” curve at the vicinity of corrosion potential Ecorr . The corrosion inhibition efficiency was evaluated from the measured icorr..This DC method of pertubution yields Rp which includes the solution resistance Rs, Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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1

M.Lavanyaa and2 M.suganya. The inhibition efficiencies were evaluate from the polarization resistance, Rp values are IE%=Rp”- Rp/ Rp”x100 ……..

(4)

Where Rpand Rp” are the polarization resistances without and the addition of inhibitors ,respectively .Z software was used for data acquisition and analysis of interfacial impedence.AC signals of 10 mV amplitude and frequency spectrum from 100 KHz to 0.01Hz was impressed and the Nyquist representations of the impedence data were analysed with View software .The charge transfer resistance Rct is obtained as the diameter of the semi circle of Nyquist curve .By doing so, in this AC method of perturbations, the contributions from the solution resistance are eliminated .The inhibition efficiency was evaluated from the measured charge transfer resistance Rct values as IE%=Rct”-Rct/Rct”x100 ………

(5)

Where Rct and Rct” are the charge transfer resistance values in the absence and presence of inhibitors, respectively. The interfacial double layer capacitance Cdl is obtained from the frequency of the point having maximum imaginary component (i.e. the point corresponding to the top of the semi circle) as Cdl=1/2 fmaxRct …………..

(6)

Where “”fmax”” corresponds to the frequency having maximum imaginary component

4. Results and Discussion 4.1 Potentiodynamic polarization study Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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M.Lavanyaa and2 M.suganya. Polarization studies were carried out in a CHI –Electrochemical workstation with impedance, Model 660A.[42-45]

Figure.1.Three electrode system A three-electrode cell assembly was used. The three electrode assembly is shown in Scheme 2. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Comparative analysis of corrosion inhibition studies on various metals in oil 1

well water using trisodium citrate as inhibitor. M.Lavanyaa and2 M.suganya.

parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic = bc) were calculated.

Stainless steel The result of the stainless steel in the blank solution the value of Ecorr is the (-152) and presence of Trisodium citrate Ecorr(-109)

Figure2.stainless steel in blank

Figure.3.stainless steel in of trisodium citrate

Mild steel The result of the mild steel in the values of the blank solution Ecorr (-550)and the presence of the trisodium citrate solution Icorr(-554).



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Figure.4. Mild steel in blank trisodium

Figure.5.mild steel in the of the trisodium

citrate

Citrate

Galvanized steel The result of the galvanized steel in the values of the blank solution Ecorr (-610) and the presence of the Trisodium citrate solution Icorr (-620).

Figure.6.galvanized steel in blank

Figure.7.galvanized steel in trisodium citrate



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1

M.Lavanyaa and2 M.suganya. 4.2.ACImpedence The effect of trisodium citrate on the behavior of stainless steel in petroleum oil water is presented in the form of Nyquist plots on figure.3. The curves show a similar type of Nyquist plots for stainless steel in the presence of trisodium citrate values of impedance parameters of stainless steel in both media are presented in The EIS technique has been one of the most used methods to report the mechanism of corrosion and corrosion protection of metals and alloys in aggressive media [17-21]. The Nyquist plots obtained for the pipeline steel electrodes at an opencircuit potential after their immersion solution Table.1.

Stainless steel Electrochemical TAFEL results in the stainless steel are absence and presence of trisodium citrate.


Figure.9.Stainless steel in trisodium citrate

citrate



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1

M.Lavanyaa and2 M.suganya. Mild steel Electrochemical TAFEL results in the mild steel in absence and presence of trisodium citrate

Figure.10. Mild steel in blank

Figure.11.mild steel in trisodium citrate

Galvanized steel The result of the galvanized steel in the values of the blank solution Ecorr (-610) and the presence of the trisodium citrate solution Icorr (-620).


Figure.13.galvanized steel in trisodium citrate



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Table.1.Electrochemical Potentiodynamic Polarization Studies of Stainless steel in the presence of trisodium citrate

SYSTEM Ecorr

Bc

b’c

LPR

Icorr

Ref

Cde

Z

Phase angle

SS 18/8

1/5.740

1/5.139

4375896

9.133X10-9

1933

-

3.746

78.24

-

4.226

73.76

4.605

22.15

7.734

102.1

2.343

35.54

2.413

34.71

-152

106.9 1826.1 SS+TSC

-252

1/7.191

1/5.946

2449089

1.351X10-8

7915 0 =7915

MS

-550

1/4.823

1/4.957

47110

9.437x10-7

40990 15030 =25960

MS+TSC

-612

1/5.005

1/4.943

138336288

3.159x10-10 4.956X107 2.407X105 =49319300

GS

-610

1/7.588

1/11.506 4590

4.961x10-6

215 30.5=184.5

GS+TSC

-659

1/5.230

1/8.478

3864

8.209 x10-6

29.2



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M.Lavanyaa and2 M.suganya. 5. Conclusion. The results obtained from present study showed that trisodiumciitrate is a good inhibitor and acted as a mixed-type inhibitor in petroleum oil water. Absorption of stainless steel, mild steel, and Galvanized steel in blank and in trisodium citrate obey in polarization and electrochemical studies.The presence of trisodium citrate inhibits the corrosion process on the stainless steel. Produce a perfect result. Environmentally acceptable organic corrosion inhibitor was used in the stainless steel perfect.

6. Reference [1]E. Stupnisek -Lisac, A. LonearicBozic I. Cafuk, Corrosion 54 (1998) 713. [2]A.Y. El-Etre, Corrosion Science, 45 (2003) 2485. [3] A.Y. El-Etre, Corrosion Science, 45(1998)1842. [4] Campbell, S., Jovancicevic, V., "Corrosion Inhibitor Film Formation Studied by ATR-FTIR", Corrosion/99, (1999) paper.no.484. [5] Videm, K. and Kvarekvaal, J., Corrosion/96, (1996) Paper NO 1. [6] Crolet, J., Thevenot, N. and Nesic, S., Corrosion/96, (1996). [7] Nesic, S., Thevenot, N., Crolet, J. and Drazic, D., Corrosion/96, (1996) Paper NO 3. [8] Heuer, J.K. and Stubbins, J.F., Corrosion, 54, (1998) P566.



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M.Lavanyaa and2 M.suganya. [9]Schmitt, G., Gudde, T., and Strobel-Effertz, E.,"Fracture Mechanical Properties of CO2 Corrosion. [10] J.Sathyabama, S.Rajendran, J.Arockiaselvi & J.eya sundari, the open corrosion journal 2(2009)76. [11]V.Kumar, corros.rev.16 (1998) 317. [12]P.Gareces, M.C.Andrade, A.Saez&M.C.Alonso, corrosion science.47 (2005) 289. [13]M.Moreno, W.morris, M.G.Alvarez and G.S.Duffo, corrosion science 46 (2004) 268. [14]X.Zhow, H.Y.Yang, F.H.wang, corrosion science&protection technology 22(4)2010(43). [15]P.Ghods, O.B.Isgaor, G.A.Mcrae, G.P.GV, corrosion science 52(5) (2010) 1649. [16]S.Agnesia Kanimozhi& S.Rajendran, International journal of electro chemical science, 4 (2009) 353. [17]Emeka E.Oguzie, corrosion science, 50(11) (2008) 2993. [18] Sastri, V. S., "Corrosion inhibitors", John Wily & Sons. Inc., ( 1998). [19] Mansfeldm, F., Kendig, M. W. and Lorenz, W. J., “Corrosion Inhibition in Neutral, Aerated Media", J. Electronchem Soc., Vol. 132, NO.2, (1985) P290-296. [21] Wang D., Li Shuyuan, Y., Wang, M., Xiao, H., Chen, Z., “Theoretical and Experimental Studies of Structure and Inhibition Efficiency of Imidazoline Derivatives", Corrosion Science, Vol. 41, (1999) P1911-1919. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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M.Lavanyaa and2 M.suganya. [22] Campbell, S., Jovancicevic, V., "Corrosion Inhibitor Film Formation Studied by ATRFTIR", Corrosion/99, (1999) paper no.484. [23] Videm, K. and Kvarekvaal, J., Corrosion/96, (1996) Paper NO 1. [24]Crolet, J., Thevenot, N. and Nesic, S., Corrosion/96, (1996) Paper NO 4. [25] Nesic, S., Thevenot, N., Crolet, J. and Drazic, D., Corrosion/96, (1996) Paper NO 4. [26] Heuer, J.K. and Stubbins, J.F., (Corrosion), 54, (1998) P566. [27] Schmitt, G., Gudde, T., and Strobel-Effertz, E., "Fracture Mechanical Properties of CO2 Corrosion Product Scales and Their Relation to Localized Corrosion", Corrosion/96, (1996) Paper NO 1.




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TEACHING OF GROUP THEORY TO THE BLIND STUDENT THROUGH VIOLIN A.John Amalraj, J.Wilson Sahayaraj, S.Arulanda Jothi, V. Dharmalingam and Susai Rajendran

TEACHING OF GROUP THEORY TO THE BLIND STUDENT THROUGH VIOLIN A.John Amalraj1, J.Wilson Sahayaraj2, S.Arulanda Jothi3, V. Dharmalingam1 and Susai Rajendran4 1

PG and Research Department of Chemistry, Periyar E.V.R College,Tiruchirappalli - 620023, Tamil Nadu, India 2

Department of Chemistry, Jeppiaar Engineering College, Chennai- 600019,Tamil Nadu, India.

3

Computer literacy program, Periyar E.V.R College, Tiruchirappalli - 620023, Tamil Nadu, India.

4

Corrosion Research Centre, Department of Chemistry, RVS Educational Trust’s Group of Institutions, Dindigul–624005, Tamil Nadu, India.

Abstract Group Theory is the mathematical application of symmetry to an object to obtain knowledge of its physical properties. The symmetry of a molecule is related to its physical properties and provides a quick simple method to determine the relevant physical information of the Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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molecule. The symmetry elements of water possess Identity, E; two reflection planes, σxz and σyz; and one 2-fold rotation axis, C2. So The point group of H2O molecule is C2V. The blind peoples are very difficult to understand the structure of the atoms, molecules and their symmetry operations. The present study is symmetry operations of molecule are performed by using musical instrument like violin. The symmetry operations of water molecule are related with musical notes. Each molecule produces a distinct tone. Since the Blind people have a strong sense of rhythm and musical sensation, they identify the point group of water molecule. Keywords: Point group; water molecule; western musical notations; violin; blind student; 1.Introduction Chemists classify molecules according to their symmetry. The collection of symmetry elements present in a molecule forms a “group”, typically called a point group. Group Theory is the mathematical application of symmetry to an object to obtain knowledge of its physical properties. The group theory brings to the table consisting the symmetry of a molecule is related to its physical properties and provides a quick simple method to determine the relevant physical information of the molecule. The symmetry of a molecule provides you with the information of what energy levels the orbitals will be, what the orbitals symmetries are, what transitions can occur between energy levels, even bond order to name a few can be found, all without rigorous calculations. The fact that so many important physical aspects can be derived from symmetry is a very profound statement and this is what makes group theory so powerful.



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A symmetry operation is an operation that is performed to a molecule which leaves it indistinguishable and superimposable on the original configuration. Symmetry operations are performed with respect to points, lines, or planes. Symmetry operation is like rotating a water molecule at an angle of 180 degree around an axis through oxygen and superimposing it on the original molecule, it is going to be the same as the original element. There are five types of operational elements for symmetry such as identity operation, rotation, reflection through a mirror plane, center of inversion and lastly the rotation about axis then reflected through a plane. The symmetry elements of water possess Identity, E; two reflection planes, σxz and σyz; and one 2-fold rotation axis, C2. So The point group of H2O molecule is C2V as shown in figure 1.



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Figure 1 : Point group(C2V) of water molecule. The blind students cannot understand the symmetry operations of water molecule. Students with visual impairments are constantly challenged by classroom instructional strategies. Although they can easily hear lectures and discussions[1], it can be difficult for them to access class syllabi, textbooks, overhead projector transparencies, power point presentations, maps, written exams, demonstrations, DVDs, videos and films. A large part of traditional learning is visual; fortunately, many students with visual disabilities have developed strategies to learn. Students that are Blind or Low Vision vary considerably. For example, Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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some have no vision; others are able to see large forms; and still others can see print if magnified. They use a variety of accommodations, equipment, and compensatory strategies based upon their widely varying needs. Many make use of taped textbooks, e-text, and computer screen reading software such as JAWS, extended time for exams or projects, a to reader/scribe during exams, large print books, and Braille materials[2-7]. The present study is undertaken that The teaching the symmetry operations of water molecule to the blind students by using musical instrument like violin through Western musical notations. The violin is called blind instrument, because there is no fixed notes (notation). The description of violin is shown in figure 2.

Figure 2. Structure of violin. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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2. Methodology The symmetry operations of water molecule are related with western musical notes. Each molecule produces a distinct tone. Since the Blind people have a strong sense of rhythm and musical sensation, they identify the point group of water molecule. The western musical notation of beats and strings are shown in figure 3.



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Figure 3 : western musicals notations 3. Results and discussion The C2V point group of water molecule contains four symmetry operations: E

the identity operation

C2 a twofold symmetry axis σv the first mirror plane (xz) σv' the second mirror plane (yz)



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These symmetry operations are correlates with western musical notes. Music can be composed and played by using violin. The symmetry elements, point group of water by mathematical way and musical way are shown in Table 1. S.No

Symmetry element

.

Point group of water by

Point group of water by musical way

mathematical way Playing Open ‘E’ string. It means that the fingers are does not touch the string. As a result the music notation produced

1

Point group C2V

The point group is C2V

some sound.

Playing Open ‘E’ string. It means that the fingers are does not touch the string. The atoms of the molecules 2

3

E, the identity operation

C2, operation

remain unchanged.

C2=180° That is θ =2Л/n Where n= order of rotation

As a result the music notation produced some sound.

The angle of rotation in violin is constructed from violin Bow. θ = full Bow / n



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θ = 2Л/n

θ = 360°/2

θ = 180°

θ = 180° As a result play in half bow in ‘E’ string. That is Timing is minimum (1 & 2) [ Bowing string only applicable for angle of rotation]

σVxz plane

The vertical plane in violin is the position of playing ‘E’ string only. it has the vertical position. Musical notation

4

The H2O molecules has the

assign through the oxygen atom.#

two (reflection) vertical

represents sharp note (through the

plane. One plane is passing

oxygen atom)

through the oxygen atoms.

H=E. O=F#, H=G (H-Hydrogen; O-Oxygen;) 5

σvyz plane

The H2O molecule has another vertical plane. That

The vertical plane in violin is the position of playing ‘E’ string only it has



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is a vertical plane containing all the atoms (Molecular plane) .

the vertical position. That is similar to the σvyz the plane containing all the atoms

Table 1 : Point group of mathematical way assign with musical way The symmetry elements of water molecule E, identity; C2 rotational axis; σVxz plane; σvyz plane confine with musical notes.

Figure 4: Music of water molecule The musicals notes are composed and played by using violin instrument as shown in figure 4. The similar exercise is applied to formaldehyde and ammonia molecule.



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4.Conclusion The blind students are very difficult to understand the structure of the atoms, molecules and their symmetry operations. Since the Blind students have a strong sense of rhythm and musical sensation, they identify the point group (C2V) of water molecule by hearing the unique music from violin. Although the group theory subject is very tough, the musical method is innovative and easy to understand to blind students. 5 Acknowledgement The Authors are very much thankful to their respective managements 6 Reference 1. F.P. Belcastro, Teaching addition and subtraction of whole numbers to blind students: A comparison of two methods. Focus on Learning Problems in Mathematics, 15(1),1993, 14-22. 2. S. Amato, S. Hong, and P. Rosenblum, The abacus: Instruction by teachers of students with visual impairments. Journal of Visual Impairment and Blindness, 107(4), 2013, 262-272

3. P. Rosenblum, and D. Smith, Instruction in specialized braille codes, abacus, and tactile graphics at universities in the United States and Canada. Journal of Visual Impairment & Blindness, 106(6), 2012, 339.

4. Norman, Katherine; et al. Teaching students with disabilities in inclusive science classrooms: Survey results, Science Education, 82 (2), 1998, 127–146. 5. Boas, E Edward , Modifying Science Instruction To Meet the Needs of the Hearing Impaired. Journal of Research in Science Teaching, 1978, 15, 257–262. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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6. Brindle, Ian D.; et al. Laboratory Instruction for the Motor Impaired. Journal of Chemical Education, 1981, 58 (3), 232–233. 7. Corn, A., Koenig, A. Least restrictive access to the visual environment. Journal of Visual Impairment and Blindness, 1991, 85, 195–197.




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Corrosion Inhibition By Natural Dyes V.Johnsirani, J.Sathiyabama and Susai Rajendran

Corrosion Inhibition By Natural Dyes V.Johnsirani1, J.Sathiyabama2 and SusaiRajendran3 1. Department of Chemistry, Sakthi college of Arts and Sc Science ience for Women, Oddanchatram, Odda Dindigul. India. E-mail: johnsirani15 @gmail.com 2. Department of Chemistry, St.Antony’s college of Arts and Sciences iences for Women, Women Dindigul624005. Abstract The Inhibition efficiency [IE] of an aqueous extract of pipali powder in controlling corrosion of carbon steell in sea water [Thondi, Tamil Nadu, India] has been evaluated by weight loss method. The weight loss study reveals that PD P formulation consisting of 10mL of PD (pipali Dye ) and 25 ppm of Zn2+ has 92% inhibition efficiency in controlling corrosion of carb carbon steel in sea water. A synergistic effect exists between PD P and Zn2+. Polarization study reveals that PD P and Zn2+ system functions as mixed type inhibitor. The nature of the metal surface has been analysed by FTIR spectra. Key words : Carbon steel,Corrosion, sea water, Electrochemmical techniques, FTIR, AFM. AFM Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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1. Introduction Plant extracts are low-cost and biodegradable, and so the study of plant extracts as corrosion inhibitors is an important scientific research field due to both economic and environmental benefits. As early as in 1930, plant extracts (dried stems, leaves and seeds) of Chelidonium majus and other plants were used as corrosion inhibitors for steel in H2SO4 pickling baths. In 1972, El Hosary et al. studied the extract of Hibiscus subdariffa (Karkode) as the corrosion inhibitor for Al and Zn in HCl and NaOH solutions. In 1980s, Saleh et al. and reported the inhibition effect of aqueous extracts of some plant leaves (Opuntia, Aleo eru) and fruit peels (orange, mango) on the corrosion of steel, aluminum, zinc and copper in acids and aluminum in NaOH solution. In 1990s, Azadirachta and Vernonia amygdalina (bitter leaf) leaves extracts were reported as good corrosion inhibitors for steel in HCl and H2SO4 solutions. Most of the inhibitors are synthetic chemicals which may be very expensive and hazardous to living creatures and environment. Natural products are one of the renewable sources, which can be used as inhibitors. Natural products in addition to their environmentally friendly and ecologically acceptable nature are inexpensive, readily available and renewable sources of materials. Among these so-called ‘‘green corrosion inhibitors” are organic compounds that act by adsorption (Ostovari et al., 2009) on the metallic surfaces. Some of these materials are honey (El-Etre et al., 2000), caffeic acid (Souza et al., 2009), caffeine (Trindade et al., 2009), Pennyroyal oil (Bouyanzer et al., 2006), alizarin (Ebenso et al., 2008), Occimumviridis extract (Oguzie, 2006), Rhizome extract (Rajendran et al., 2005), Zenthoxylum alatum extract (Chauhan et al., 2007), Lawsonia (El-Etre et al., 2005; Rajendran et al., 2009), Berberine (Li et al., 2005), garlic extract (Rajendran et al., 2009) and several other extracts of natural substances (Bothi Raja et al, 2008; Sangeetha et al.,2011). The efficiency of these organic corrosion inhibitors is related to the presence of polar functions with S, O or N atoms in their molecular structure, heterocyclic compounds and π electrons (Satapathy et al., 2009). Phenolic compounds that exist in these plant extracts effectively adsorbed on the metal Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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surface and then impede the corrosion process (Ostovari et al., 2009; Anuradha et al. 2008). The phenolic content of Chamomile flowers consist of flavonoids, including flavone glycosides (e.g., apigenin 7-glucoside) and flavonols (e.g., quercetin and luteolin glucosides) and phenolic acids including caffeic, chlorogenic, etc (Harbourne et al., 2009). Some authors (Mladěnka et al., 2011) have demonstrated that these phenolic compounds interact with iron. In this research, the corrosion inhibition of carbon steel, in sea water extract of Pipali (Piper longum L.) have been investigated. 2. EXPERIMENTAL 2.1 Preparation of Pipali Dye 10gm of Pippali (Piper longum L.) powder was weighed and boiled with double distilled water. The greydye Pippali was filtered to remove suspended impurities and made up to 100mL. The pippali dye (PD) was used as corrosion inhibitor in the present study. 2.2. Preparation of carbon steel specimens Carbon steel specimens (0.02 6% S, 0.06% P, 0.4% Mn, 0.1% C and rest iron) of tPE dimensions 1.0 x 4.0 x 0.2 cm were polisPEd to a mirror finish, degreased with trichloroethylene, and used for tPE weight-loss method and surface examination studies. 2.3. Weight- loss method Carbon steel specimens were immersed in 100 ml of the medium containing various concentrations of the inhibitor in the absence and presence of Zn2+ for one day. The weights of the specimens before and after immersion were determined using a Digital Balance (Model AUY 220 SHIMADZU). The corrosion products were cleaned with Clarke’s solution . The corrosion IE was then calculated using the equation. IE = 100 [1-(W2/W1)] % Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Where W1 is the weight loss value in the absence of inhibitor W2 is the weight loss value in the presence of inhibitor. Corrosion rate was calculated using the formula Corrosion rate (mm/year) = 87.6 W/ DAT Where W = weight loss in milligram ,D = density of specimen g/cm3 ,A = area of specimen in square cm, T = exposure time in hours. 2.4 Potentiodynamic Polarization Study: Polarization studies were carried out in a CHI- electrochemical work station with impedance model 660A. It was provided with iR compensation facility. A three electrode cell assembly was used. The working electrode was carbon steel. A SCE was the reference electrode. Platinum was the counter electrode. From polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr), Tafel slopes anodic = ba and cathodic = bc were calculated and linear polarization study (LPR) was done. The scan rate (V/S0.01. Hold time at (Efcs) was zero and quiet time (s) was two. 2.5 Surface examination study: The carbon steel specimens were immersed in various test solutions for a period of one day. After one day, the specimens were taken out and dried. The nature of the film formed on the surface of the metal specimen was analyzed for surface analysis technique by FTIR spectra. 2.6 Fourier transform infrared spectra: Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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These spectra were recorded in a Perkin-Elmer-1600 spectrophotometer using KBr pellet. The FTIR spectrum of the protective film was recorded by carefully removing the film, mixing it with KBr and making the pellet. 3. Results and Discussion 3.1 Analysis of the results of weight loss method The values of IE for different concentrations of PD in the absence and presence of Zn2+ in sea water for a period of one day obtained from the weight loss method are given in Table 3.1. It can be seen that Zn2+ alone has some inhibitive properties. IE increases as the concentration of PD increases. As the concentration of Zn2+ increases, IE also increases. Upon addition of 10 mL of PD, IE dereases. This is due to the fact that the complex (Fe2+ -active principle in PD) formed on the metal surface dissolves and goes into solution. Similar observation has been made in the case of corrosion inhibition by Henna extract . However, it is observed that when the concentration of Zn2+ increases from 25 ppm to 50 ppm, the IE slightly decreases. This may be due to the fact that, when the concentration of Zn2+ increases, the Zn2+ - PD complex formed is precipitated in the bulk of the solution. Hence PD is not transported towards the metal surface. So, the IE decreases. The formulation consisting of 10 mL of PD and 25 ppm of Zn2+ has 92% IE. Therefore, mixture of inhibitors shows better IE than individual inhibitors. This suggests a synergistic effect existing between PD and Zn2+ .

Table.3.1

Inhibition efficiency (IE) of PD-Zn2+ system in the corrosion of

carbon steel immersed in sea water (Immersion period-1 day)



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Zn2+ (ppm) PD (mL)

0

25

50

CR (mm/y)

CR (mm/y)

CR (mm/y)

0

0.1576

0.1323

0.0835

2

0.0788

0.0472

0.0394

4

0.0740

0.0394

0.0362

6

0.0709

0.0236

0.0299

8

0.0630

0.0173

0.0252

10

0.0583

0.0126

0.0236

Table.3.2 corrosion rates (CR) in millimeter per year (mm/y) of carbon steel immersed in sea water in the presence of PD-Zn2+ system (Immersion period-1 day) Zn2+ (ppm) PD (mL)

0

25

50

IE (%)

IE (%)

IE (%)

0

-

16

47

2

50

70

70

4

53

75

72

6

55

85

81

8

60

89

84

10

63

92

85



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100 90 80 70 IE (%)

60 50

0 mL Zn

40

25 mL Zn

30

50 mL Zn

20 10 0 0

2

4

6

8

10

PD (mL)

Fig.3.1 Graph of inhibition efficiency (IE) of PD – Zn2+ system in the corrosion of carbon steel immersed in sea water (Immersion period – 1 day)

3.2 Synergism parameter (SI) Synergism parameter is calculated to evaluate the synergistic effect existing between inhibitors . The synergism parameter (SI) can be calculated using the relationship given by Aramaki and Hackermann . SI =1- =1 1+2/ 1-’1+2 ........ Where 1+2

= (1+2) -(1 x 2)

1

= surface coverage of inhibitor (PD)

2

= surface coverage of inhibitor (Zn2+)

’1+2 = combined surface coverage of inhibitors (PD) and (Zn2+) Surface coverage = IE%/100 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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SI approaches 1 when no interaction exists between the two inhibitors. When SI > 1, synergistic effect exists between the two inhibitors. In the case of SI< 1, negative interaction takes place between the two inhibitors, (i.e, CR increase) The calculated synergism parameter values are given in Table 3.2a and 3.2b. The SI value is found to be greater than one indicating synergistic effect existing between Zn2+ of concentrations 25 ppm and 50 ppm with various concentrations of PD . Thus the enhancement of the IE caused by the addition of Zn2+ ions to PD is due to the synergistic effect. The above result is in accordance with the interpretations made by Sangeetha et al. while discussing the values of SI are slightly smaller in the case of 25 ppm of Zn2+ when compared with 50 ppm of Zn2+. This is in line with the inhibition efficiencies obtained by weight loss method. Thus the values of synergism parameters given have quantitative value of synergism existing between the two inhibitors.

Table 3.2a

Synergism parameters for PD-Zn2+ (25 ppm) system, when carbon steel immersed in sea water (Immersion period-1 day) PD (mL)

1

2

’1+2

SI

2

0.50

0.16

0.70

1.4

4

0.53

0.16

0.75

1.5792

6

0.55

0.16

0.85

2.52

8

0.60

0.16

0.89

3.0545

10

0.63

0.16

0.92

3.885



123


Table 3.2b Synergism parameters for PD-Zn2+ (50 ppm) system, when carbon steel immersed in sea water (Immersion period-1 day)

3.3

PD (mL)

1

2

’1+2

SI

2

0.50

0.47

0.75

1.06

4

0.53

0.47

0.77

1.0830

6

0.55

0.47

0.81

4.0078

8

0.60

0.47

0.84

1.325

10

0.63

0.47

0.85

1.3073

Analysis of results of potentiodynamic polarization study for the PDsystem Polarization study has been used to detect the formation of protective film on the metal

surface during corrosion inhibition process. The potentiodynamic polarization curves obtained for carbon steel in sea water without and with inhibitors (10 mL of PD + 25 ppm Zn2+) are shown in Fig.3.2. The cathodic branch represents the oxygen reduction reaction, while the anodic branch represents the iron dissolution reaction. The electrochemical parmmeters such as corrosion potential (Ecorr), corrosion current (Icorr), Tafel solpes (ba and bc), linear polarization resistance (LPR) are given in Table 3.3. When carbon steel is immersed in sea water, the corrosion potentials is -816 mV vs SCE. The inhibitor system shifts the corrosion potential to -815 mV vs SCE. The corrosion potential shift is very small. This suggests that the PD-Zn2+ formulation functions as a mixed inhibitor controlling the anodic reaction and cathodic reaction, to the same extent



124


The corrosion current value and LPR value for sea water are 6.354×10-6 A/cm2 and 6.500 x 103 ohm cm2. In the presence of the inhibitors, the corrosion current value has decreased to 5.848 x 10-6 A/cm2, and the LPR value is increased to 6.988 x 103 ohm cm2.This indicates that a protective film is formed on the metal surface, LPR value increases and corrosion current value decreases .

Fig..3.2 Polarization curves of carbon steel immersed in various test solutions (a) Sea water (b) Sea water containing 10mL of PD and 25 ppm of Zn2+ Table3.3 Corrosion parameter of carbon steel immersed in sea water in the absence and presence of inhibitor system (PD-Zn2+ ) obtained from polarization method

Inhibitor PD mL

Zn2+ ppm

Ecorr mVvs

Icorr

ba

bc

LPR

A/cm

mV/dec

mV/dec

ohm cm2

2

SCE

0

0

-816

6.354×10-6

239

157

6.500×103

10

25

-815

5.848×10-6

239

154

6.988×103



125


3.4 Analysis of FTIR spectra The main constituent of pippali dye is pipperine. The grey colour of the extract is due to Pipperine. The structure of pipperineis shown in Scheme 3.1 .The pippali dye extract was evaporated to dryness to get a solid mass. Its FTIR spectrum of the solid mass is shown in Fig 5.4.6a.The –OH stretching frequency appears at 3418cm-1. The C=O stretching frequency appears at 1710cm-1. Thus, Pippali dye was characterized by IR spectroscopy.

The FTIR

spectrum of the protective film formed on the surface of the metal after immersed in the solution containing 25 ppm of Zn2+ and 10mL of PD shown in Fig3.3.. It is found that the -OH has shifted from 3418 cm-1 to 3437 cm-1. The C=O stretching frequency has decreased from 1710cm-1 to 1630cm-1. It was inferred that PD has coordinated with Fe2+ through the phenolic oxygen and carbonyl oxygen, resulting in the formation of the Fe2+ - PD complex on the anodic sites of the metal surface. The peak at 1367cm-1 is due to Zn-O band. The peak at 3437cm-1 is due to –OH stretching. Hence it is confirmed that Zn(OH)2 is formed on the cathodic sites of the metal surface.Thus, the FTIR spectral study leads to the conclusion that the protective film consists of the Fe2+- PD complex and Zn(OH)2 [6-25].

Scheme.3.1. Structure of piperine Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


126


Fig.3.3 FTIR spectra a) Pure PD b) Film formed on metal surface after immersion in sea water containing 10mL of PD – 25 ppm Zn2+ 3.5 Mechanism of corrosion inhibition In order to explain the corrosion inhibition of carbon steel immersed in sea water containing PD (10 mL)-Zn2+ (25 ppm) the following mechanism may be proposed. 

When the formulation consists of PD (10 mL)- Zn2+ (25 ppm) in sea water there is formation of Zn2+ -piperine complex in solution.



When carbon steel is immersed in this solution piperine -Zn2+ complex diffuses from the bulk of the solution towards the metal surface.



Piperine -Zn2+ complex is converted into piperine - Fe2+ complex on the anodic sites of the metal surface with the release of Zn2+ ion.



127




Zn2+- piperine + Fe2+ →Fe2+- piperine + Zn2+



The released Zn2+ combines with OH-- to form Zn(OH)2 on the cathodic sites of the metal surface. Zn2+ + 2OH--→ Zn(OH)2↓



Thus the protective film consists of piperine -Fe2+ complex and Zn(OH)2.



AFM images confirm the formation of protective layer on the metal surface.

References [1] Raja P.B., Sethuraman M.G., Natural products as corrosion inhibitor for metal in corrosive Media – a review, Mater. Lett., 62, 113 -116 (2008) [2] El Hosary A.A., Saleh R.M., Shams El Din A.M., Corrosion inhibition by naturally occurring Substances.I. Effect of Hibiscus subdariffa (karkade) extract on the dissolution of aluminum and Zinc, Corros. Sci., 12, 897-904 (1972) [3] Saleh R.M., Ismail A.A., El Hosary A.A., Corrosion inhibition by naturally occurring Substances. V11. The effect of aqueous extracts of some leaves and fruit peels on the Corrosion of steel, aluminium, zinc and copper in acids, Br. Corros. J., 17, 131- 135 (1982) [4].Saleh R.M., Ismail A.A., El Hosary A.A., Corrosion inhibition by naturally occurring Substances. V11. The effect of aqueous extracts of some seeds, leaves, fruits peels on the Corrosion of aluminium in sodium hydroxide, Corrs. Sci., 23, 1239 - 1241 (1983) [5]. Ekpe U.J., Ebenso E.E., Ibok U.J., Inhibitory action of Azadirachta leaves extract on Corrosion of mild steel in tetraoxosulphate (VI) acid, J. West African Assoc., 37, 13-30 (1994) [6]. C.A. Loto The effect of Vernonia amygdalina (bitter leaf) solution extract on the Corrosion inhibition of mild steel, Nig. Cor. J., 19, 20-28 (1998) [7] S. Rajendran, M. Agasta, R. Bama

Devi, B. Shyamala Devi,

K. Rajam

and

J. Jayasundari,

Zastita Materijala, 50 (2009) 77. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


128


[8] T. Umamathi, J. Arockia Selvi, S. Agnesia Kanimozhi, S. Rajendran and A. John Amalraj, Indian J.Chem. Technol.,15 (2008) 560. [9] Y.Y. Thangam, M. Kalanithe, C.M. Anbarasi and S. Rajendran, Arabian J. Sci. Engg., 34 (2009) 49. [10] S.Rajendran, B.R.E.J. Peter, A.P.P. Regis, A.J. Amalraj and M.Sundaravadivelu, Transactions of the SAEST., 38 (2003) 11. [11] S. Rajendran, S.M. Reinkala, N. Anthony and R. Ramaraj, Corros Sci., 44 (2002)449. [12] J. Sathyabama, S. Rajendran, J.A. Selvi and S. Jeyasundari, Bulg. Chem.

Commun., 41

(2009) 374. [13] Xianghong Li, Shuduan Deng, Hui Fu and Guannan Mu, Corros. Sci., 50 (2008) 2635. [14] G.K. Gomma, Mater. Chem. Phys., 55 (1998) 241. [15] K. Aramaki and Hackermann, J. Electrochem. Soc., 116 (1969). [16] D. Gopi, S. Manimozhi, K.M. Govindaraju, P. Manisankar and S. Rajeswari, J. Appl. Electrochem.,37 (2007) 439. [17] C.A. Loto, R.T. Loto and A.P.I. Popoola, Intl. J. Electrochem. Sci., 6 (2011) 3830. [18] X.Li, S. Deng, H. Fu and G. Mu, Corros. Sci., 52 (2010) 1167.1 [19] M.Sangeetha, S. Rajendra4n, J. Sathiyabama, A.Krishnaveni, P. Shanthy, N. Manimaran, B. Shyamaladevi, Portugaliae Electrochim. Acta., 29 (2011) 429. [20] S.Rajendran, A. Raji, J.Arockia Selvi, A.Rosaly and S.Thangasamy, J. Mater.Edun.,29 (2007) 245. [21] S.Rajendran, A. Raji, J. Arockia Selvi, A. Rosaly and S. Thangasamy, Edutracks., 6 (2007) 30.



129


[22] S.Merah, L. Larabi, O. Benali and Y. Harek, Pigment Resin Technol., 37(5) (2008) 291. [23] H.Benita Sherine,

A. Jamal Abdul Nasser

and

S. Rajendran, In. J. Eng. Sci.

Technol.,24 (2010) 341. [24] SS. Agnesia Kanimozhi and S. Rajendran, Arab. J. Sci. Eng., 34 (2009) 37. [25] C.Mary Anbarasi and S. Rajendran. J. Electrochem. Sci. Eng., 1(2011) 15.




130

Decolourisation of Dyes of Textile Industries By Biochemical Methods. Methods

T. Marimuthu, S.Rajendran .

DECOLOURISATION OF DYES OF TEXTILE INDUSTRIES BY BIOCHEMICAL METHODS T. Marimuthu1*, S.Rajendran2,3 1Research and Development Centre, Bharathiar University, Coimbatore,Tamil Nadu, India. CELLNO :9942255402 email:[email protected] 2Corrosion Research Centre, PG and Research department of chemistry, GTN Arts college, Dindigul, Tamil nadu, India. CELLNO: 9443631628 3Department of Chemistry, RVS School of Engineering and Technology, Dindigul,Tamil Nadu, India. email : susairajendran @gmail.com

Abstract A variety of synthetic dyestuffs were released from the textile industry ry and made a threat to environmental safety. fety. Azo dyes account for the majority of all dyestuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Existing effluent treatment procedures are unable to remove various dyes completely c from effluents because of their color fastness, stability and resistance to degradation. Bacterial decolorization orization and degradation of dyes under certain environmental conditions. conditions The method of treatment, as these are inexpensive, eco-friendly eco and can be applied to wide range of such dyes. This study mainly focuses on the different of bacterial decolorization processes and find a solution to decolorization of dyes and dye effluents. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 131 Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

131

Decolourisation of Dyes of Textile Industries By Biochemical Methods.

T. Marimuthu, S.Rajendran . Key words :dye decolorization ,bacterial decolorization, dye effluent. 1.INTRODUCTION BACTERIA BIODEGRADATION Efforts to isolate bacterial cultures [1-9]capable of degrading azo dyes started in the 1970s with reports of a bacillus subtilis (Horitsu et al., 1977), followed by numerous bacteria pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders( Yu et al, 2001); Chang et al(2004) used the extracellular metabolites of a dye-decolorizing strain, Escherichia coli strain NO3, as a biostimulator to entice E. coli strain NO3 into a beneficial mode of metabolism for an conomically feasible colorization.To design technical decolorization processes of textile wastewater treatment with sulfide produced by reducing bacteria (SRB) was designed to decolorize textile wastewater treatment with sulfide(Yoo, 2002) .In general, the wastewater from textile industry contains many various dyes. To gain a widespread reception, the azo-degrading bacteria should exhibit decolorizing ability for a wide range of dyes, aeromonas hydrophila was selecte from six bacterial strains with the capability of degrading textile dyes (Chen et al, 2003). 2.MATERIALS AND METHODS The present study has been carried out to find the suitable bioremediation measures of textile dye effluent by using Biological and chemical agent. SAMPLE COLLECTION The dye effluent was collected from the Balammalpuran in Karur. The samples were collected by using sterile sample bottles and transported to the laboratory within 24 hrs of collection. The collected samples were stored at low temperature for further analysis. 2.1.ENUMERATION OF TOTAL MICROBES IN THE DYE EFFLUENT SAMPLE Total microbial counts in the dye effluent sample serially diluted (10ˉ¹to 10ˉ9). One ml from the dilution 10-3 was plated in Nutrient agar plates, using spread plate method and incubated at 37oC for 24 hrs for bacterial counts and PDA agar for fungal counts incubated at 28⁰C for 48 hrs. Colonies on the plates were counted by using colony counter. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

132


T. Marimuthu, S.Rajendran . The Bacterial cultures were isolated and identified by pure culture and Biochemical methods. Bacterial culture isolated from dye effluent sample, dilution 0.1ml of sample was inoculated on Nutrient Agar plates and kept for incubation at 37oC for 24 hrs. broth and were incubated at 370 C for three days and 3 ml of alpha napthol was added followed by 1 ml of 40% KOH. It was mixed well and allowed to stand for 30 min. The results were interpreted based on the change of colour to pink. 2.2 ASSAY OF DECOLORIZATION ACTIVITY The bacterial strains (Bacillus, Pseudomonas, Acineto bacter, Legionella,Staphylococcus) and were grown on PDA agar plates and were streaked on plates containing dyes in media. The plates contained MM2 – Carbon, MM2 – Nitrogen, MM2 – Nitrogen – Carbon. Decolorization of the dye was visually observed for the extent of zone clearing on the plates.The extent of dye decolorization by the microbial cultures in broth was determined by spectrophotometer at the maximum absorbance of the respective dyes in the cell free extracts. The percentage of dye decolorization by the cells was done using the modified method of Yatome et al., (1991). Cultures were grown in 50 ml of broth for overnight at 37o C and 80 rpm to an OD of 1.00 at 600nm. The cultures were centrifuged at 10,000 rpm for 10 min. and washed twice with sterile saline (0.85%) and resuspended in 10 ml of saline solution. 0.1ml of the inoculum was added to the broth containing dye and incubated at 37°C, 85 – 110 rpm for 24 hr. The supernatant was collected after centrifugation for absorbance measurement at respective wavelengths. The percentage decolorization was calculated as follows: % age Decolorization = Initial O.D - Final O.D X100 Initial O.D 2.3. ANALYSING

OF PHYSICO-CHEMICAL

PARAMETERS

OF

THE

DYE

EFFLUENT SAMPLE The dye effluent sample was used for various Physico-chemical analysis viz., colour of the sample, Odour by direct smelling of the sample, Standard thermometer was used for temperature measurements, The pH of the sample was determined by pH meter. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

133


T. Marimuthu, S.Rajendran . ADMI color was determined with a Spectrophotometer in accordance with the ADMI Tristimulus method 2120 D detailed in Standard Methods (1998). The spectrophotometer was calibrated before each use with standard platinum cobalt color solutions of 100, 200, 300, 400, and 500 ADMI color units. (Edwards, 2000). Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) were analyzed.

2.4 .BIOLOGICAL OXYGEN DEMAND (BOD): Adjust the pH of water sample to neutrality using 1N acid or 1N alkaline solutions. Fill the water sample in 6 BOD bottles without bubbling. Add 1 ml of Allyl thiourea to each bottle. Determine dissolved oxygen content in 3 of the 6 BOD bottles by titration method. Take the mean of the 3 readings (D1). Incubate the rest of 3 BOD bottles at 27ºC in a BOD incubator for 3 days. Estimate the oxygen concentration in all the 3 incubated samples. Take the mean of 3 readings (D2). Calculate the BOD of water in mg/l by using the following formula BOD (mg/l) = D1-D2 ,Where, D1

=

Initial dissolved oxygen in the sample (mg/l)

D2

=

Dissolved oxygen in the water sample (mg/l) after 3 days of incubation.

2.5. CHEMICAL OXYGEN DEMAND (COD) Take three , 100 ml conical flasks and pour 50 ml of water sample in each ( i.e., in triplicate). Simultaneously run distilled water blank standards (also in triplicate). Add 5 ml of potassium dichromate solution in each of the 6 flasks. Keep the flasks in water bath at 100ºC for 1 hour. Allow the samples to cool for 10 minutes. Add 5 ml potassium iodide solution in each flask. Add 10 ml of H2SO4 in each flask. Titrate the contents of each flask with 0.1 M of sodium thiosulphate solution until the appearance of pale yellow colour. Add 1 ml of starch solution to each flask (solution turns blue colour). Titrate the again with 0.1 M sodium thiosulphate until the blue colour disappears completely. Find out the COD (mg/l) of the water sample by using the following formula Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

134


T. Marimuthu, S.Rajendran . 8*C*(Vв-VA)*1000 COD of the sample (mg/l) =

-------------------------S

Where, C

=

Concentration of titrant (0.l M)

Vв

=

Volume of titrant used for sample (ml)

VA

=

Volume of titrant used for blank (ml)

S

=

Volume of sample taken (ml)

2.6 .DEGRADATION ANALYZING FOR BACTERIA The isolated Bacterial samples Bacillus sp, Pseudomonas sp, Acineto bacter, Legionella and Staphylococcus was checked for the extent of dye degradation both in solid media plates as well as in liquid media.

All the isolates gave maximum degradation. Visual degradation

indicated that degradation was higher in case of broth as compared to minimal media. The overnight broth cultures (Bacillus sp, Pseudomonas sp, Acineto bacter, Legionella and Staphylococcus) with crude oil were centrifuged and resuspended in 10 ml of saline solution and 0.1ml of the inoculum was added to the broth containing crude oil and incubated at 37°C, 85 – 110 rpm for 24 hr. The supernatant was collected after centrifugation for absorbance measurement at 650 nm wavelengths. Among the five isolated bacterial strains, Pseudomonas showed higher degradation than Bacillus. The percentage degradation was calculated and given in Table-1 TABLE – 1 BACTERIAL DECOLORIZATION OF DYE EFFLUENT S.

BACTERIAL

NO

CULTURES

1

Bacillus sp

2

Pseudomonas sp

O.D BEFORE

O.D AFTER

DECORIZATION DECORIZATION

PERCENTAGE OF DEGRADATION (%)

0.34

0.12

65

0.34

0.09

73

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

135



3

Acineto bacter

0.34

0.16

52

4

Legionella

0.34

0.19

45

0.34

0.14

58

Staphylococcus

5

% OF DECOLORIZATION

% OF Decolorization 80 70 60 50 40 30 20 10 0

% OF Decolorization

BACERIAL STRAIN

Fig -1 Bacterial Decolorization After inoculation of isolated microorganisms, the physico-chemical physico chemical parameters were analyzed for 2 weeks intervals.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 131 Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

136



Table -2 COD Removal by bacterial strain COD mg per litre S.NO

1 2

Bacterial strain

Bacillus sp Pseudomonas sp

%OF COD

FIRST

3

6

9

12

DAY

DAYS

DAYS

DAYS

DAYS

938

872

801

743

688

26.65

938

863

737

624

502

46.48

REMOVAL AFTER 12 DAYS

3

Acineto bacter

938

789

671

409

374

60.12

4

Legionella

938

857

789

737

645

31.23

5

Staphylococcus

938

865

798

714

632

53.94

5OF COD REMOVAL

70 60 50 40 30 20

% OF COD Removal by bacterial strain

10 0

BACERIAL STRAIN

Fig -2 2 COD Removal by bacterial strain


137



Table -3 BOD Removal by Baterial strain BOD mg perlitre S.NO

Bacterial strain

FIRST DAY

3 DAYS

6 DAYS

9 DAYS

12 DAYS

%OF BOD REMOVAL AFTER 12 DAYS

1

Bacillus sp

45

41

35

29

26

42.22

2

Pseudomonas sp

45

38

34

29

24

46.66

3

Acineto bacter

45

37

32

30

27

40.0

4

Legionella

45

42

38

33

29

35.5

5

Staphylococcus

45

43

37

35

32

28.88


138



50 45

% BOD Removal by bacterial strain

40 35 30 25 20 15 10

5 0

Fig -3 3 BOD Removal by Baterial strain Table -4 pH variations by bacterial strain pH S.NO

Bacterial strain

FIRST

3

6

9

12

DAY

DAYS

DAYS

DAYS

DAYS

1

Bacillus sp

8.1

7.7

7.5

7.3

7.2

2

Pseudomonas sp

8.1

8.0

7.8

7.7

7.6

3

Acineto bacter

8.1

7.9

7.7

7.6

7.3

4

Legionella

8.1

7.8

7.6

7.5

7.4

5

Staphylococcus

8.1

8.0

7.9

7.7

7.5


139



pH

VARIATION

8 7.8 PH

7.6 7.4 7.2 7 6.8 7.7

8.O

7.9

7.8

8.O

8.1

8.1

8.1

8.1

8.1

Legionella

Staphylococcus

Bacillus sp Pseudomonas spAcineto sp bacter SAMPLE NO

FIG :4

pH

VARIATION BY BACERIAL STRAIN

In the present study, decolorization proceeded gradually even up to 12 days in effluent-adapted effluent bacterial treatment. Effluent adapted bacillus sp gave 35.68% reduction in color according acco to olukanni et al .but but present work gave 73% of decolorization of dye effluent only. The microbes utilized carbon, nitrogen and sulphate found in effluent medium for their nutrition. Decolorization % will be further increased and prolonged by supplementing the effluent medium with other cheaper effective carbon or energy source such as sucrose, sucro starch and hydrolysed starch. Acineto bacter had high COD removal % (60.12) and pseudomonas sp had high BOD removal % (46.66)

4.CONCLUSION Bacteria is a cheaper and better environment friendlier alternative for colour removal in textile dye effluents.biological logical treatment has been effective in reducing dye house effluents and when used properly has a lower operating cost than other remediation decolorization process. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 131 Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

140


T. Marimuthu, S.Rajendran . Microbial consortium has become a very good source for the textile industry in getting rid of theireffluent problem by Biodegradation and Decolorization process. Since they are cost effective and efficient it is highly recommended for the industries in making use of

the

consortium for the proper disposal of textile effluents.

5. REFERENCES [1]M. Iqbal, A. Saeed Process Biochem, 2007, 42, 1160-1164. [2] Z. Aksu, A.I. Tatli, O. Tunc, Chem Eng J, 2008 , 1422, 23-39. [3)]M.A. Khalaf, Bioresource Technol,2008, 99, 6631-6634. [4]O. Anjaneya, M. Santhosh kumar, S. Nayak Anand, T.B. Karegoudai, det Biodeg, 2009, 63, 782-787. [5]I. Kiran, S. Iihan, N. Caner, C.F. Iscen, Z. Y ildiz, Desalin,2009, 249, 273-278. [6]X.J. Xiong, X.J. Meng, T.L. Zheng, J Hazard Mater , 2010,175, 241-246. [7] Kapdan, K.I., F. Kargi, G. McMullan and R. Marchant(2000).: Effect of environmental conditions

on biological decolorization of textile dyestuff by C. versicolor. Enzyme and Microbial Technoloy, 26, 381-387. [8] Faryal,R., Hameed,A. 2005. Isolation and characterization of various fungal strains from textile

effluent for their use in bioremediation. Pak.J.Bot.; 1003-1008. [9] Khadijah,O., Lee,K.K., Mohd Faiz F., Abdullah. 2009. Isolation, screening and development of

local bacterial consortia with azo dyes decolourising capability. Malaysian Journal of Microbiology.;25-32.

Received -8-09-2016 Accepted -13-09-2016 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 131-141 Editors: Dr S Rajendran, A Christy Catherine Mary

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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika .

CORROSION RESISTANCE PROPERTY OF MILD STEEL IN SIMULATED CONCRETE PORE SOLUTION PREPARED IN WELL WATER BY USING A AN AQUEOUS EXTRACT OF NEEM S.Shanmugapriya(a) S.Rajendran(b) ,P.Prabakar(c), N.karthika (d) [a]Department of Chemistry , Madha Engineering College, Kundrathur, Chennai, India. Email: [email protected]. [b]Department of Chemistry, St.Antony’s College of arts and sciences for women ,Dindigul – 624 0 05,Tamil Nadu, India, Email:[email protected]. [c] Department of Chemistry, APA College of Arts and Culture, Palani, India. [d]Department of Chemistry,SBM college of Engineering and Technology, Dindigul,India

ABSTRACT Corrosion resistance of mild steel immersed in simulated concrete pore solution (SCPS) prepared in well water has been evaluated by weight loss method, in the absence and presence of an aqueous extract of neem, It is observed that in the presence of an aqueous extract of neem corrosion inhibition efficiency increases. The mechanistic aspects of corrosion inhibition have been studied by weight loss method, polarisation study and AC impedance spectra. In the presence of the neem extract, the inhibition efficiency increases, linear polarisation resistance value increases ;corrosion current decreases ;charge transfer resistance value increases and double layer capacitance decreases. Thus it is observed that in Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . the presence of a green inhibitor the corrosion resistance of mild steel incorporated in concrete structure increases. Thus the corrosion resistance of mild steel incorporated in concrete structure can be improved by addition of an aqueous extract of neem. Key words: corrosion inhibition, mild steel, simulated concrete pore solution, Neem extract, green chemistry 1. INTRODUCTION It is generally accepted that Reinforced concrete is one of the most widely used engineering materials for construction, and its durability is a major problem affecting the service life of the engineering structures due to the reinforcing steel corrosion. Which results in a huge economic loss [1]-[3] Under normal conditions, reinforcing steel in concrete can be protected from corrosion by forming a compact passive film on its surface in concrete pore solution with high alkalinity (pH 12.5-13.5). However, the passive film can be locally damaged and the localized corrosion of reinforcing steel takes place when pH and/or the chloride concentration at the Steel/ concrete interface reach the critical values for corrosion[4]-[9] The pH of concrete pore solution decreased during concrete carbonation due to the neutralization of Ca (OH) 2 in the interstitial solution with the acidic gases (CO2, SO2, etc.) which diffuse into the steel/concrete interface from the air. The pH value of concrete pore solution is one of the most important parameters affecting the corrosion behaviour of reinforcing steel in concrete. In spite of the extensive studies of corrosion behaviours of reinforcing steel[4]-[10], the exact mechanism of its depassivation is still unclear. Even though the effect of pH on the corrosion of reinforcing steel was discovered decades ago, there were only a few studies focusing on the depassivation of the steel caused by decreasing pH of concrete pore solution during the carbonation process[11]-[13]. In the urban and industrial areas, the acidic gases (CO2, SO2, NO2, etc.) can make the local atmosphere acidic and attack the hydrated concrete. The reactions of neutralization in concrete may decrease the pH value of concrete pore solution, induce the steel surface depassivation and consequently cause the steel corrosion. Several research papers have investigated the corrosion behaviour of metals in presence of simulated concrete pore (SCP) solutions [14]-[25]. Usually steel rebar have been Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . used in such studies. The Present Study is undertaken to investigate the corrosion of mild steel in SCPS prepared in well water solution, in the absence and presence of an aqueous extract of neem 2.0 EXPERIMENTAL SECTION 2.1. Preparation of the specimens: Mild steel specimen was used in the present study. (Composition (wt %): 0.026 S, 0.06 P, 0.4Mn, 0.1C and balance iron. The dimension of the specimen was 1 x 4 x 0.2cm were polished to a mirror finish and degreased with trichloroethylene and used for the weight-loss method and surface examination studies. The environment chosen is well water and the physic-chemical parameter of well water is given in table 1. 2.2. Preparation of Simulated Concrete pore solution (SCPS): Simulated concrete pore solution is mainly consisted of saturated calcium hydroxide Ca(OH)2, sodium hydroxide(NaOH) and potassium hydroxide (KOH) with the pH ~13.5. However in numerous studies of rebar corrosion, saturated Ca (OH)2 has been used as a substitute for pore solution. A saturated calcium hydroxide solution is used in present study, as SCP solution with the pH ~ 12.5. Table – 1 Physico- chemical parameters of well water Parameters pH conductivity chloride sulphate TDS Total hardness Total alkalinity Magnesium Potassium Sodium Calcium

Value 8.32 1772Ω-1cm-1 660ppm 212ppm 1200ppm 400ppm 392ppm 80ppm 52ppm 170ppm 84ppm

2.3. Preparation of aqueous extract of neem



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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . 10 gram of dried neem leaves powder is boiled with double distilled water for 10 minutes and the suspended particles are removed by filtration and the solution is made up to 100 ml and can be used as corrosion inhibitor Weight loss method Weighing the specimens before and after Corrosion: All the weighing of the mild steel specimens before and after corrosion was carried out using Shimadzu balance, model AY62. Determination of Corrosion Rate: The weighed specimens in triplicate were suspended by means of glass hooks in100 ml SCPS prepared in well water containing various concentration of aqueous extract of asafoetida the specimen were taken out, washed in running water, dried, and weighed. From the change in weights of the specimens, corrosion rates were calculated using the following relationship: CR = [(Weight loss in mg) / (Area of the specimens in dm2 × Immersion periods in days)] mdd---- (1) Corrosion inhibition efficiency (IE, %) was then calculated using the equation: I.E =100[1-(W2/W1)] % ---(2) Where, W1= corrosion rate in the absence of the inhibitor, and W2 = corrosion rate in the presence of the inhibitor, 2.4 Potentiodynamic Polarization: Polarization studies were carried out in a CHI – Electrochemical workstation with impedance, Model 660A.A three-electrode cell assembly was used. The three electrode assembly is shown in Fig-1. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic =bc) and Linear polarization Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . resistance (LPR) were calculated. The scan rate (V/S) was0.01.Hold time at (Efcs) was zero and quit time(s) was two.

2.5 AC impedance spectra AC impedance spectral studies were carried out in a CHI – Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. The real part (Z’) and imaginary part (Z”) of the cell impedance were measured in ohms at various frequencies. Values of the charge transfer resistance (Rt) and the double layer capacitance (Cdl) were calculated

RESULTS AND DISCUSSION Analysis of results of the weight loss method The calculated inhibition efficiencies(IE) and corrosion rates(CR) of neem extract in controlling corrosion of mild steel immersed in simulated concrete pore solution(SCPS) for a Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . period of one day in aqueous extract of neem is given in Table 2. The inhibition efficiency is also given in this Table 2 Corrosion rate in well water = 49.72mdd

Table 2; Inhibition Efficiency (IE%) and Corrosion rate (CR) obtained from neem system in controlling corrosion of mild steel immersed in Simulated concrete pore solution (SCPS) prepared in well water Various concentrations of the aqueous extract of neem (2ml, 4ml, 6ml, 8ml, and 10ml) were added to the SCPS system. The corrosion inhibition efficiency slowly increased. The maximum inhibition efficiency was found to be 95%. Thus it is observed that when 10 ml of asafoetida extract is added to SCPS, the inhibition efficiency increases from 85%to 95% Analysis of poentiodynamic polarization curves Electro chemical structures such as Polarization study have been used to confirm the formation of protective film formed on the metal surface during the corrosion inhibition process [10]-[20].If a protective film is formed on the metal surface, the corrosion value (Icorr ) decreases. The potentio dynamic polarisation curve of mild steel immersed in well water in the absence and presence of inhibitor are shown in Fig-2. The LPR value is 23537.8 Ohm/cm2. The corrosion current is 1.835x10-6 A/cm2. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . When mild steel is immersed in SCPS solution, the corrosion potential shifts to the anodic side (-525mv Vs SCE). This indicates that there is passivation of metal by formation of protective film on the anodic sides of the metal surface. This is confirmed by the decrease in LPR value from 23537.8 to 26795.8 Ohm cm2. Further the corrosion current decreases from 1.835x10-6A/cm2 to 1.573x10-6A/cm2. When 10 ml of aqueous extract of neem is added, the corrosion potential is shifted to -575 v s SCE. When compared to well water system , there is no shift in corrosion potential, this indicates that neem combines with SCPS system function as mixed type of inhibitor(i.e.) both anodic and cathodic reactions are controlled. The LPR value increases to 38621.2 Ohm/cm2, further the corrosion current decreases to 1.109x 10-6 A/cm2. Thus it is observed that when neem extract is added, the corrosion resistance of mild steel in SCPS increases

Table 3: corrosion parameters of mild steel immersed in well water and SCPS in theabsence and presence of inhibitor neem extract



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Fig 2 :polarisation curves of mild steel in various test solutions Analysis of AC impedance spectra AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface. If a protective film is formed on the metal surface, charge transfer resistance decreases and the impedance log (z/ohm) value increases [25]-[29].When mild steel is immersed in well water charge transfer resistance (Rt) is 4080 Ohm/ cm2 and double layer capacitance (Cdl)value is12.5x 10-10F /cm2 The impedance log (z/ohm) value is equal to3.805 log (z/ohm). When mild steel is immersed in well water and simulated concrete pore solution, charge transfer resistance (Rt) value increases from 4080 Ohm/ cm2 to 4680 Ohm/ cm2 and double layer capacitance (Cdl)value decreases from 12.5x 10-10F /cm2 to10.9 x10-10F /cm2 The impedance log (z/ohm) value increases from 3.805 log (z/ohm) to3.844 log (z/ohm)When mild steel is immersed in well water with simulated concrete pore solution and neem extract charge transfer resistance (Rt) value increases to 6584Ohm/ cm2 and double layer capacitance (Cdl)value decreases to7.746 x 10-10F / cm2 The impedance log (z/ohm)

value increases to3.964 log (z/ohm)

thus the analysis of AC

impedance spectra lead to the conclusion that in the presence ofSCPS+neem system, the Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . corrosion resistance of mild steel increases.This is due to the formation of protective film formed on the metal surface. The protective film probably consist of iron complexof the active principle present in neem

Fig 3;AC Impedance specra of mild steel immersed in various test solutions (nyquist plot)



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Table 4: corrosion parameters of mild steel immersed simulated concrete pore solution in the absence and presence of inhibitor neem extract obtained from AC impedance spectra

CONCLUSION 

Corrosion resistance of mild steel immersed in simulated concrete pore solution (SCPS) prepared in well water has been evaluated by weight loss method, in the absence and presence of an aqueous extract of neem.



It is observed that in the presence of an aqueous extract of neem corrosion inhibition efficiency increases. The mechanistic aspects of corrosion inhibition have been studied by polarisation study and AC impedance spectra.



In the presence of neem extract, linear polarisation resistance value increases; corrosion current decreases; charge transfer resistance value increases and double layer capacitance decreases



Thus it is observed that in the presence of a neem the corrosion resistance of mild steel incorporated in concrete structure increases.



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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . 

Thus the corrosion resistance of mild steel incorporated in concrete structure can be improved by addition of an aqueous extract of neem. This novel green technology will be useful in construction technology.

ACKNOWLEDGMENT The authors are thankful to their respective management for their help and support REFERENCE 1 Ahmad S, Cement Concrete Comp., 2003, 25, 459. 2. Biezma M V and San J R, Cristobal, Corros Eng Sci Technol., 2005, 40, 344. 3. Thangavel K, Corros Rev., 2004, 22, 55. 4. Moreno M, Morris W, Alvarez M.G and Duffo G S, Corros Sci., 2004, 46(11), 2681-2699. 5. Kumar V, Corros Rev., 1998, 16, 317. 6. Maslehuddin M, Al-Zahrani M M, Ibrahim M, Al-Mehthel M H and Al-Idi S H, Constr Build Mater., 2007, 21(8), 1825-1832. 7. Du R.G, Hu R.G, Huang R.S and Lin C J, Anal Chem., 2006, 78(9), 3179-3185. 8. Huet B, L’Hostis V, Miserque F and Idrissi H, Electrochem Acta, 2005, 51(1), 172-180. 9. Alonso C, Castellote M and Andrade C, Electrochim Acta, 2002, 47(21), 3469-3481. 10. Poupard O, Ait-Mokhtar A and Dumargue P, Cement Concrete Res., 2004, 34, 991-1000. 11. Duffo G S, Morris W, Raspini I and Saragovi C, Corros Sci., 2004, 46, 2143. 12. Yeih W C and Chang J, J Constr Build Mater., 2005, 19, 516. 13. Garces P, Andrade M C, Saez A and Alonso M C, Corros Sci., 2005, 47(2), 289-306. 14. Zhou X, Yang H Y and Wang F H, Corros Sci Protect Technol., 2010, 22(4), 343-347. 15. Fajardo S, Bastidas D M, Ryan M P, Criado M, McPhail D S and Bastidas J M, Appl Surface Sci., 2010, 256(21), 6139-6143. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Resistance Property Of Mild Steel In Simulated Concrete Pore Solution Prepared In Well Water By Using A An Aqueous Extract of Neem S.Shanmugapriya, S.Rajendran ,P.Prabakar, N.karthika . 16. Chen W, Du R G, Ye C-Q, Zhu Y-F and Lin C-J, Electrochim Acta, 2010, 55(20), 5677- 5682. 17. Wang L and Zhao Y-L, Tiedao Xuebao/J China Railway Soc., 2010, 32(4), 96-101. 18. Chastre C and Silva M A G, Eng Struct., 2010, 32(8), 2268-2277. 19. Suh K, Mullins G, Sen R and Winters D, J Compos Constr., 2010, 14(4), 388-396. 20. Zhang J X, Sun H H, Sun Y M and Zhang N, J Zhejiang University Sci A, 2010, 11(5), 382-388.

Received-9 -09-2016 Accepted-14-09-2016



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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli

GREEN SYNTHESIS OF COPPER NANOPARTICLES USING DELONIX ELATA FLOWER EXTRACT M.Suganya[a] and G.Valli[b] [a]* Department of Chemistry and Physics Nadar Saraswathi College of Arts and Science Theni. Tamil Nadu, India.Email:[email protected] [b] MTWU, Kodaikanal. Tamil Nadu, India. Email: [email protected] Abstract The importance of Delonix elata flower and Copper nanoparticles as revealed by various literature resources, we planned to carry out biogenic synthesis of Copper nanoparticles using the above extract. Copper nanoparticles were prepared by adopting standard procedure.

The

formations of Copper nanoparticles from the extracts were identified first by observing the colour changes. The extract colour changes during the formation of Copper nanoparticles from dark brown to light green colour for Delonix elata. Copper nanoparticle formations were characterized by UV, FT-IR, XRD and SEM. UV absorbance at 328nm for Copper nanoparticles derived from the above flower extract. The IR spectrum of copper nanoparticles isolated using OH stretching at Delonix elata flower extract copper showed Cu –O stretching at 403cm-1 and proved by the diminished intensity of bonded OH(3000-3500cm-1) of the IR spectra of flower extract copper Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli nanoparticles. XRD & SEM analysis of copper nanoparticles indicated that they exist in amorphous in nature and with size range 20µm. Keywords: Delonix elata flower, Copper nanoparticles, FT-IR, XRD &SEM. 1. Introduction Delonix elata commonly known as white gold mohur and family Leguminosae [1]; subfamily Caesalpiniaceae. Commonly known as ‘‘Sandesaro” in Gujarati [2]. Delonix elata has been reported to have antioxidant, anti-arthritic, anti-ulcer and anti-inflammatory activity. Large red-orange in color having five petals, one petal contains also white color streaks and little bit big as compare to other petals, four spreading scarlet or orange-red petals up to 8 cm long having same size and colour, a fifth upright petal called the standard, which is slightly larger and spotted with yellow and white. Sepals 5, thick, green outside and reddish with yellow border within, reflexed when the flowers are open, pointed, finely hairy, about 2.5 cm long. Stamens 5 with 10 red filaments. Pistil has a hairy 1celled ovary about 1.3cm long. Style about 3 cm long [3-5]. The members of the genus are flowering trees, native to the East Africa, has been used in traditional Indian medicine for the treatment of rheumatism, stomach disorders [6]. The Delonix plant was reported to have anti-arthritic and anti-inflamatory activities [7]. Flavonoids, tannins, alkaloids, saponins, steroids carotenoids (lycopene, phytoene, phtofluene, β-carotene, prolycopene, neolycopene, δ-lycopene and γ-lycopene), phenolic acid (gallic acid, protocatehuic acid, salicylic acid, trans-cinnamic acid andchlorogenic acid), anthocyanins (cyanidin-3-glucoside and cyanidin3-gentiobioside and β-sitosterol[7, 8-10]. 2.Experimental methods 2.1 Materials and Methods Used a)Materials Delonix elata flower collected from Theni district were used to make ethanolic extract. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli i) Preparation of the Delonix elata flower Extract: The Delonix elata flowers were washed several time with water to remove dust particles and then dried to remove the residual moisture. The Delonix elata flower extract used for reduction of copper sulphate to copper nanoparticles, was prepared by placing 5g of washed dried fine separately grinded flowers powder in 250ml round bottom flask along with 200ml of ethanol. The mixture was then boiled for 4 hours until the colour of the ethanolic extract changes to brown. Then the extract was cooled to room temperature and filtered with Whatmann No.1 filter paper to get an extract. The ethanolic extract used as a reducing agent for further nanoparticle synthesis .These extract can be stored at room temperature for one week. ii)Synthesis of copper nanoparticles from Delonix elata flower extract 1mM aqueous solution of copper sulphate was prepared and used for synthesis copper nanoparticles. 10ml of Delonix elata flower extract was added into 90 ml of aqueous solution of 1mM copper sulphate for reduction to copper ions and kept at room temperature for one day. As a result a light green solution was formed indicating the formation of copper nanoparticles and it was further confirmed by UV-Visible and other spectral studies Figure-32.

Figure -32(a)

Figure -32(b)

Figure -32 Photographs showing a) Pure Delonix elata flower Extract Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli b) Colour changes after adding flower Extract to copper sulphate solution. iii)Separation of copper nanoparticles: The synthesized copper nanoparticles was separated by means of centrifugation (Spectrofuge 7M) at 3000 rpm for 15 mins. The pellets was redispersed and again centrifuged for 15 mins. The supernatant solution thus obtained was stored at -4 . 2.2 Characterization of Copper Nanoparticles Characterization of copper nanoparticles was first carried out using UV-Visible absorption spectrometer 2400PC with a resolution of 1nm between 200 and 800nm possessing a scanning speed of 200nm/min. Equivalent amounts of the suspension were diluted with constant volume of deionized water and subsequently analyzed at room temperature. The extracts were monitored by UV-Visible spectra of copper nanoparticles in aqueous solution shown in Figure-33. The reduction of pure copper ions was monitored by measuring the UV-vis spectrum of the reaction medium after diluting a small aliquot of the sample into ethanol. A light brown colouration was noticed at the synthesis phase. The concentration of copper nanoparticles produced was measured using a Systronics UV double-beam spectrophotometer (model 2400PC), at a resolution of 1 nm, between 200 and 800 nm possessing a scanning speed of 200 nm/min. Absorption spectra of copper nanoparticles formed in the reaction media have absorbance peak at 328nm for Delonix elata. 2.3 FTIR The characterization of functional groups on the surface of copper nanoprticles by flower extracts were investigated by FT-IR measurements were carried out on a Instrument IRTRACER100 Model and the spectra was scanned in the range of 370-4000 cm-1. FTIR spectrum of Cu nanoparticles suggested that Cu nanoparticles binds with oxygen present in the phytoconstituent were surrounded by different organic molecules such as alcohols, ketones, aldehydes and carboxylic acid. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli 2.4 X-Ray Diffraction The particle size and nature of the copper nanoparticles were determined using Bruker Eco D8 Advance X-pert PRO operating at a voltage of 40kV, a current of 20mA with copper Kα radiation at 2θ angle ranging from 100 to 800 .The average XRD particle size amorphous nature. The crystalline copper nanoparticle was calculated from the width of the XRD peaks and the average size of the nanoparticles can be estimated using the Debye Scherrer D =kλ/βcosθ Where, D = Thickness of the nanocrystal, K = Constant, Λ = Wavelength of X-rays, Β = Width at half maxima of reflection at Bragg’s angle 2θ, θ = Bragg angle. 2.5 SEM Each sample for SEM examination was initially deposited onto a thin mica strip using a glass pipette, the mica strip was attached to a SEM using carbon tape. The samples were then dried under vacuum overnight. The following day, all samples were sputter coated with a 2nm layer. The pellet was subjected for SEM analysis. Thin films of the sample were prepared on a carbon coated copper grid by just dropping a very small amount of the sample on the grid, extra solution was removed using a blotting paper and then the film on the SEM grid were allowed to dry for analysis. The SEM image of Delonix elata flower stabilized copper nanoparticles prepared from copper sulphate salt is shown in Figure-37. From the image, it was revealed that nanoparticles were of in cluster. The surfaces of the aggregates was rough clearly with an average particle size around 20µm. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli 3. RESULT The formation of copper nanoparticles can be observed by the change in the color of the solution from dark brown to light green for Delonix elata flower after one day. The appearance of brown color was due to the excitation of surface plasmon vibrations of copper nanoparticles. i)UV-VISIBLE SPECTROSCOPY The reduction of pure copper ions was monitored by measuring the UV-vis spectrum of the reaction medium after diluting a small aliquot of the sample into ethanol. A light brown colouration was noticed at the synthesis phase. The concentration of copper nanoparticles produced was measured using a Systronics UV double-beam spectrophotometer (model 2400PC), at a resolution of 1 nm, between 200 and 800 nm possessing a scanning speed of 200 nm/min. Absorption spectra of copper nanoparticles formed in the reaction media have absorbance peak at 328nm for Delonix elata.

Figure -33 UV- Visible Spectra of copper nanoparticles ii) FTIR SPECCTRAL STUDIES The IR spectrum of copper nanoparticles assisted by Delonix elata copper showed Cu –O stretching and at 403cm-1 proved by the diminished intensity of bonded OH(3000-3500cm-1) of the IR spectra of flower extract. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Figure -34 FT-IR Spectrum of Delonix elata flower extract

Figure -35 FT-IR Spectrum of copper nanoparticles iii) X-RAY DIFFRACTION The particle size and nature of the copper nanoparticles were determined using Bruker Eco D8 Advance X-pert PRO operating at a voltage of 40kV, a current of 20mA with copper Kα radiation at 2θ angle ranging from 100 to 800 .The average XRD particle size amorphous nature.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Figure -36 XRD spectrum of copper nanoparticles iv) SEM The SEM image of Delonix elata stabilized copper nanoparticles prepared from copper sulphate salt is shown in Figure37. From the image, we conclude that the nanoparticles are clustered. The surfaces of the aggregates are rough clearly with an average particle size around 20µm.

Figure -37 SEM Spectrum of copper nanoparticles CONCLUSION Green synthesis of copper nanoparticles CuNp’’s using Delonix elata flowers were performed by adopting standard procedure were characterized by UV–vis, FT-IR ,XRD Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli and SEM studies. The formation of copper nanoparticle was identified by the colour changes from dark brown light green colour for Delonix elata flower extract. UV absorption studies of copper nanoparticles showed that the absorbance peak at 328nm for Delonix elata flower extract. The IR spectrum of copper nanoparticles assisted by Delonix elata copper showed Cu –O stretching and at 403cm-1 proved by the diminished intensity of bonded OH(3000-3500cm-1) of the IR spectra of flower extract. The SEM analysis of CuNp’s from that their sizes were in the range of 20µm. REFERENCES [1]Rao R.V. Krishna, Rao Ganapathy P. Mallikarjuna and Rao B.Ganga. Antiinflammatory activity of the leaves and bark of Delonix elata. Ancient Science of Life. 17 (2), (1997)141 – 143. [2]Wijayasiriwardena C., Sharma P. P., Chauhan M. G., Pillai A.P.G. Delonix elata (L.) Gamble from folklore practice; AYU. 30(1), (2009)68-72. [3]On line. http://en.wikipedia.org/wiki/Delonix_regia. Reterived on July 28, (2012). [4]Ponnusami V., Aravindhan R., Karthik N. Raj, Ramadoss G., Srivastava S.N. Adsorption of methylene blue onto gulmohar plant leaf powder: Equilibrium, kinetic, and thermodynamic analysis. Journal of environmental protection science; 3, (2009)1– 10. [5]Jahan Israt, Rahman Mohamaad S., Rahman Mohammad Z., Kaisar Mohammad A., Islam Mohamaad S., Wahab Abdul and Rashid Mohammad A. Chemical and Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Green synthesis of copper nanoparticles using Delonix elata flower extract M.Suganya & G.Valli biological investigation of Delonix regia (Bojer ex. Hook) Raf. Acta Pharmaceutica; 60(2), (2010)207-215. [6]Thirugnanam S, Mooligai M. (Tamil) Trichy: Selvi Publishers. p.33, (2003)117, 131, 139,147. [7]Sivanarayana V., Suryavathana. Preliminary studies, phytochemical and antimicrobial activity on Delonix elata and Prosopis cineraria. International journal of current research.; 8, (2010)66-69. [8]Parekh J, Chanda SV. In vitro activity and phytochemical analysis of some Indian medicinal plants. Turk J Biol; 31,( 2007) 53-58. [9]Shabir Ghulam, Anwa Farooq, Sultana Bushra, Khalid Zafar M., Afzal Muhammad, Khan Qaiser M. and M. Ashrafuzzaman. Antioxidant and antimicrobial attributes and phenolics of different solvent extracts from leaves, flowers and bark of Gold mohar [Delonix regia (Bojer ex Hook.) Molecules ,16, (2011)7302-7319. [10]Adje Felix, Lozano Yves F., Meudec Emmanuelle, Lozano Paul, Adima Augustin, Agbo N’zi Georges and Gaydou Emile M. Anthocyanin Characterization of Pilot Plant Water Extracts of Delonix regia Flowers. Molecules; 13, (2008)1238-1245.

Received-15-09-2016 Accepted-20-09-2016 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Applications of Cyclic voltammetry in Corrosion inhibition studies M.Pandiarajan, S.Rajendran and J.Sathiya bama

Applications of Cyclic voltammetry in Corrosion inhibition studies M.Pandiarajan1, S.Rajendran2 and J. Sathiya bama1,R, Joseph Rathis 3and S .Santhana Prabha3 1

PG and Research Department of Chemistry, GTN Arts College, Dindigul-624005, Dindigul 624005, India. Email: [email protected].

2

Department of Chemistry, St Antony’s College of Arts and Sciences for Women, Amala Annai Nagar, Thamaraipadi (Post),Dindigul – 624 005, Tamilnadu, India. Email: Email [email protected]. 3

PSNS College of Engineering and Technology, Dindigul, India

Abstract Cyclic voltammetry or CV is a type typ of potentiodynamic electrochemical measurement. It is an electrochemical method which measures the current that develops in an electrochemical cell under conditions where voltage ltage is in excess of that predicted by the Nernst equation. CV is performed by cycling the potential of a working electrode, and measuring the resulting current. In a cyclic voltammetry experiment the working electrode potential is ramped linearly versus time. Unlike in linear sweep voltammetry, voltammetry, after the set potential is reached in a CV experiment, the working electrode's potential is ramped in the opposite direction to return to the initial potential. These cycles of ramps in potential may be repeated as many times as desired. The current at the electrode is plotted versus the applied voltage (i.e., the working electrode's Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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potential) to give the cyclic voltammogram trace. Cyclic voltammetry is generally used to study the electrochemical properties of an analyte in solution, and also used examine the reversibility of the adsorption process and its effect on oxygen reduction current. Key words: cyclic voltammetry, linear sweep voltammetry, electrochemical, current, potential. 1. INTRODUCTION Frank R. Foulkes et al., have been investigated A rapid cyclic voltammetric method for studying the influence of cement factors on the corrosion of embedded iron and steel in hardened cement paste is described. The technique employs a “cement electrode” consisting of an iron or steel wire embedded in a miniature cylinder of hardened cement paste. The rapid cyclic voltammetric method is fast, reproducible, and provides information on the corrosiveness of the pore solution environment surrounding the embedded metal. The usefulness of the method is demonstrated by showing how it can be used to evaluate the threshold chloride content of hardened ordinary portland cement paste at which corrosion begins and by using it to evaluate the relative efficacy of several admixed corrosion inhibitors [1]. Deyab and Keera have been analysed the influence of sulphide, sulphate, and bicarbonate anions on the pitting corrosion behaviour of mild steel in formation water containing chloride ions by means of cyclic voltammetry technique. The cyclic voltammograms were recorded in the presence of increasing amounts (0.1 to 0.3M) of NaCl at a scan rate of 10 mV s-1. The anodic response exhibits a well defined anodic peak followed by a passive region. The anodic peak is due to active metal dissolution and formation of ferrous hydroxide . The cathodic sweep shows two cathodic peaks. The appearance of cathodic peak around 1.1 V is due to reduction of corrosion product, namely iron oxide to iron. The appearance of cathodic peak around -0.7 Vis due to the reduction of pitting corrosion products precipitate on the electrode surface [2]. 2. EXPERIMENTAL



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Figure 1. Cyclic voltammetry Measurements using model 2450

Instrumentation: A cyclic voltammetry (CV) system consists of: 1. Electrolysis cell , Potentiostat, Current to voltage, converter, Data acquisition system 2. The electrolysis cell consists of: Working electrode, Counter electrode, Reference electrode, Electrolytic solution, The current to voltage converter measures the resulting current, and the data acquisition system produces the resulting voltammogram. Cyclic sweeps are used to measure corrosion that proceeds at about the same rate over the entire metal's surface (uniform) and corrosion at discrete sites on the surface, such as pitting crevice and stress corrosion cracking (localized). Cyclic voltammetry involves applying voltage to an electrode immersed in an electrolyte solution, and seeing how the system responds. In CV, a linear sweeping voltage is applied to an aqueous solution containing the compound of interest. CV provides the capability for generating a species during the forward scan and then determining its outcome with the reverse scan or subsequent cycles, all within seconds. The potential is measured between the reference and working electrodes, and the current is measured between the working and counter electrodes. To measure uniform corrosion, the method of Tafel extrapolation is used, the Tafel slope being the slope of the straight line portion of the semi logarithmic polarization curve. To determine the degree of localized corrosion, the amount of hysteresis between the positive sweep and the negative sweep is calculated. CV differs from polarography in two important ways: Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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The working electrode rode at which the reactions of interest occur has a constant area, not one which changes with time as in classical polarography. The potential of the working electrode is scanned rapidly over a wide potential range and then returned to its initial value using using an applied potential signal which varies linearly with time between the initial value and the final value at the limit of the forward scan [3].

Figure 2. Typical cyclic voltammogram where

and

show the peak cathodic and anodic

current respectively for a reversible reaction. The potential of the working electrode is measured against a reference electrode which maintains a constant potential, and the resulting applied potential produces an excitation signal such as that of figure 2. In the forward scan an of figure 2,, the potential first scans negatively, starting from a greater potential (a) and ending at a lower potential (d). The potential extrema (d) is call the switching potential, and is the point where the voltage is sufficient enough to have caused caus an oxidation or reduction of an analyte. The reverse scan occurs from (d) to (g), and is where the potential ntial scans positively. Figure 3 shows a typical reduction occurring from (a) to (d) and an oxidation occurring from (d) to (g). It is important to no note te that some analytes undergo oxidation first, in which case the potential would first scan positively. This cycle can be repeated, and the scan rate can be varied. The slope of the excitation signal gives the scan rate used. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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Figure 3: CV Excitation Signal

A cyclic voltammogram is obtained by measuring the current at the working electrode during the potential scans. Figure 4 shows a cyclic voltammogram resulting from a single electron reduction and oxidation. Consider the following reversible reaction:

Figure 4: Voltammogram of a Single electron oxidation –reduction



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In Figure 4, the reduction process occurs from (a) the initial potential to (d) the switching potential. In this region the potential is scanned negatively to cause a reduction. The resulting current is called cathodic current (ipc). The corresponding peak potential occurs at (c), and is called the cathodic peak potential (Epc). The Epc is reached when all of the substrate at the surface of the electrode has been reduced. After the switching potential has been reached (d), the potential scans positively from (d) to (g). This results in anodic current (Ipa) and oxidation to occur. The peak potential at (f) is called the anodic peak potential (Epa), and is reached when all of the substrate at the surface of the electrode has been oxidized.

Figure 5. Cyclic voltammetry waveform. In cyclic voltammetry, the electrode potential ramps linearly versus time in cyclical phases as shown in Figure 5. The rate of voltage change over time during each of these phases is known as the experiment's scan rate (V/s). The potential is applied between the working electrode and the reference electrode while the current is measured between the working electrode and the counter electrode. These data are plotted as current (i) vs. applied potential (E, often referred to as just 'potential'). In Figure 5, during the initial forward scan (from t0 to t1) an increasingly reducing potential is applied; thus the cathodic current will, at least initially, increase over this time period assuming that there are reducible analytes in the system. At some point after the reduction potential of the analyte is reached, the cathodic current will decrease as the concentration of reducible analyte is depleted. If the redox couple is reversible then during the reverse scan (from t1 to t2) the reduced analyte will start to be re-oxidized, giving rise to a current of reverse polarity Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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(anodic current) to before. The more reversible the redox couple is, the more similar the oxidation peak will be in shape to the reduction peak. Hence, CV data can provide information about redox potentials and electrochemical reaction rates. For instance, if the electron transfer at the working electrode surface is fast and the current is limited by the diffusion of analyte species to the electrode surface, then the peak current will be proportional to the square root of the scan rate. This relationship is described by the Cottrell equation. In this situation, the CV experiment only samples a small portion of the solution, i.e., the diffusion layer at the electrode surface. A standard CV experiment uses a reference electrode, working electrode, and counter electrode. This combination is sometimes referred to as a three-electrode setup. An electrolyte is usually added to the sample solution to ensure sufficient conductivity. The solvent, electrolyte, and material composition of the working electrode will determine the potential range that can be accessed during the experiment. The electrodes are immobile and sit in unstirred solutions during cyclic voltammetry. This "still" solution method gives rise to cyclic voltammetry's characteristic diffusion-controlled peaks. This method also allows a portion of the analyte to remain after reduction or oxidation so that it may display further redox activity. Stirring the solution between cyclic voltammetry traces is important in order to supply the electrode surface with fresh analyte for each new experiment. The solubility of an analyte can change drastically with its overall charge; as such it is common for reduced or oxidized analyte species to precipitate out onto the electrode. This layering of analyte can insulate the electrode surface, display its own redox activity in subsequent scans, or otherwise alter the electrode surface in a way that affects the CV measurements. For this reason it is often necessary to clean the electrodes between scans. Common materials for the working electrode include glassy carbon, platinum, and gold. These electrodes are generally encased in a rod of inert insulator with a disk exposed at one end. A regular working electrode has a radius within an order of magnitude of 1 mm. Having a Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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controlled surface area with a well-defined shape is necessary for being able to interpret cyclic voltammetry results. To run cyclic voltammetry experiments at very high scan rates a regular working electrode is insufficient. High scan rates create peaks with large currents and increased resistances, which result in distortions. Ultra microelectrodes can be used to minimize the current and resistance. The counter electrode, also known as the auxiliary or second electrode, can be any material which conducts current easily and will not react with the bulk solution. Reactions occurring at the counter electrode surface are unimportant as long as it continues to conduct current well. To maintain the observed current the counter electrode will often oxidize or reduce the solvent or bulk electrolyte. Reference electrodes are a complex subject and worth investigating elsewhere. 3. Cyclic Voltametry: The Principles We shall see how this measurement can be employed to study the electron transfer kinetics and transport properties of electrolysis reactions. Cyclic voltammetry (CV) is very similar to LSV(Linear Sweep Voltammetry). In this case the voltage is swept between two values (see below) at a fixed rate, however now when the voltage reaches V2 the scan is reversed and the voltage is swept back to V1

A typical cyclic voltammogram recorded for a reversible single electrode transfer reaction is shown in below. Again the solution contains only a single electrochemical reactant Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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The forward sweep produces an identical response to that seen for the LSV experiment. When the scan is reversed we simply move back through the equilibrium positions gradually converting electrolysis product (Fe2+ back to reactant (Fe3+). The current flow is now from the solution species back to the electrode and so occurs in the opposite sense to the forward seep but otherwise the behaviour can be explained in an identical manner. For a reversible electrochemical reaction the CV recorded has certain well defined characteristics. I) The voltage separation between the current peaks is

II) The positions of peak voltage do not alter as a function of voltage scan rate III) The ratio of the peak currents is equal to one

IV) The peak currents are proportional to the square root of the scan rate



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As with LSV the influence of scan rate is explained for a reversible electron transfer reaction in terms of the diffusion layer thickness. The CV for cases where the electron transfer is not reversible show considerably different behaviour from their reversible counterparts. The figure below shows the voltammogram for a quasi-reversible reaction for different values of the reduction and oxidation rate constants.

The first curve shows the case where both the oxidation and reduction rate constants are still fast, however, as the rate constants are lowered the curves shift to more reductive potentials. Again this may be rationalised interms of the equilibrium at the surface is no longer establishing so rapidly. In these cases the peak separation is no longer fixed but varies as a function of the scan rate. Similarly the peak current nolonger varies as a function of the square root of the scan rate. By analysing the variation of peak position as a function of scan rate it is possible to gain an estimate for the electron transfer rate constants [4].

Applications of Cyclic Voltammetry Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Cyclic voltammetry (CV) has become an important and widely used electro analytical technique in many areas of chemistry. It is often used to study a variety of redox processes, to determine the stability of reaction products, the presence of intermediates in redox reactions, reaction [5] and electron transfer kinetics, and the reversibility of a reaction CV can also be used to determine the electron stoichiometry of a system, the diffusion coefficient of an analyte, and the formal reduction potential of an analyte, which can be used as an identification tool. In addition, because concentration is proportional to current in a reversible, Nernstian system, the concentration of an unknown solution can be determined by generating a calibration curve of current vs. concentration. Cyclic Voltammetry can be used to study qualitative information about electrochemical processes under various conditions, such as the presence of intermediates in This latter application is gaining interest in the field of cellular biology where it is used to measure the concentrations of various chemicals in the cells of organisms, including living ones[5-10]. This technique has been used to investigate corrosion behavior of metals and to analyze the influence of sulphide, sulphate and bicarbonate anions on the pitting corrosion behavior of carbon steel in water containing chloride ions. M.Pandiarajan had been used the cyclic voltammetry to investigate the corrosion behaviour of metala using cyclic voltammograms were recorded by measuring the working electrode, mild steel, in 3.5% NaCl solution. The cyclic voltammogram of mild steel immersed in 3.5% NaCl is shown in Fig.6. It is observed that during anodic scan, no peak is observed but a passive state is noticed. This can be explained as follows: When the metal dissolves, ferrous hydroxide is formed. When the concentration of ferrous oxide at the anodic surface exceeds its solubility product, precipitation of solid oxide occurs on the electrode surface. When the surface is entirely covered with oxide passive film, anodic current density does not increase indicating onset of passivation. In the passive state, the Cl- ion can be adsorbed on the bare metal surface in competition with OH- ions. As a result of high polarizability of the Cl- ions, the Cl- ions may adsorb preferentially. The cyclic voltammetry parameters are given in Table 1.The cathodic sweep shows only one peak at 0.652V.This is due to the reduction of corrosion product, iron Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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oxide to iron. The peak due to reduction of pitting corrosion product is absent. (This reveals that pitting corrosion does not take place under the given experimental conditions). The cyclic voltammogram of mild steel, which has been immersed in SCPS for one day and dried is shown in Fig.7. (brown iron oxide was observed on the mild steel electrode). It is observed that during anodic sweep, no peak appears, but a passive region is observed. During the cathodic sweep, the peak due to reduction of pitting corrosion product appears at -955mV indicating that pitting corrosion takes place. However, the peak due to reduction of corrosion product, iron oxide, appears at -2.7 V. The current density increases from -2.5 x10-3 A to -4.6x10-3 A. This indicates that when mild steel electrode is immersed in SCPS for one day, a protective film of iron oxide is formed on the electrode surface. It is stable in 3.5% NaCl solution. The increase in current density is explained as follows: Chloride ion is adsorbed on the passive film. The adsorbed chloride ion penetrates the oxide film especially at the flaws and defects in the oxide film .When the penetrated chloride ion reaches the metal surface, they promote local corrosion. When the mild steel electrode is immersed in SCPS water containing 100 ppm of PC and 50 ppm of Zn2+ for one day, a protective film is formed. It consists of Fe2+– PC complex, Zn2+– PC complex, and Zn (OH)2 as revealed by FTIR spectroscopy. The cyclic voltammogram of mild steel electrode deposited with the above protective film is shown in Fig.8. It is observed that during anodic sweep, dissolution of metal does not take place. This indicates that the protective film is stable and compact. Electrons are not transferred from the metal surface, and a passive region is observed. During cathodic sweep, the peak corresponding to reduction of pitting corrosion product appears at -530 mV. However, the peak due to reduction of iron oxide to iron appears at -1.4V. The current density increases from -2.5 x10-3 A to -4.0 x10-3 A. The increase in current density may be explained as above. It is observed from the Fig. 6,7,8 that the pitting potentials for the three systems are at -656 mV, -970 mV, and -520 mV respectively. That is when mild steel electrode is immersed in the SCPS medium; the pitting potential is shifted to more negative side (active side, i.e., -970mV). It accelerates corrosion because the protective film formed is porous and amorphous. When the electrode is immersed in Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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the inhibitor medium, the pitting potential is shifted shifted to the noble side, i.e., -520mV. This indicates that the passive film found on the metal surface in the presence of inhibitors is compact and stable. It can withstand the attack of chloride ion present in 3.5 NaCl. Table 1. Cyclic voltammetry parameters (PC + Zn2+)

Sample Control ( mild steel)

Ep (V)

Peak ip (A)

Pitting

Pitting

Corrosion

Potential

product(mV)

(mV)

0.652

-2.5

-----

-656

Blank ( SCPS)

-2.7

-4.6

-955

-970

Inhibitor system

-1.4

-4.0

-530

-520

(PC + Zn2+)

Figure 6. Cyclic voltammogram of mild steel electrode immersed in 3.5% NaCl.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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Figure 7. Cyclic voltammogram of mild steel electrode submerged in 3.5% NaCl solution after its immersion in SCPS for one day

Figure 8.Cyclic voltammogram of mild steel electrode submerged in 3.5% NaCl solution after its immersion in SCPS containing 100 ppm of PC and 50 ppm of Zn2+ for one day References 1.Frank R.Foulkes, Patrick McGrath , Cement and Concrete Research, 1999,29, 873-883. 2. Deyab M.A., Keera S.T. Egyption Journal of petroleum, 2012, 21,31-36. 3. https://en.wikipedia.org/wiki/Cyclic_voltammetry 4. http://www.ceb.cam.ac.uk/research/groups/rg-eme/teaching-notes/linear-sweep-and-

cyclic-voltametry-the-principles. 5. Wightman, R. Mark (2006). "Probing Cellular Chemistry in Biological Systems with Microelectrodes". Science 311 (5767): 1570– doi:10.1126/science.1120027. PMID 16543451. 6."The use of cyclic voltammetry in the study of carbonyls". J.Chem.Educ. 65: 1020. doi:10.1021/ed065p1020.

the

chemistry

of

metal



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7. Sanghavi, Bankim; Srivastava, Ashwini (2010). "Simultaneous voltammetric determination of acetaminophen, aspirin and caffeine using an in situ surfactant-modified multiwalled carbonnanotubepasteelectrode". ElectrochimicaActa 55:8638–8648 . 8.Sanghavi, Bankim; Mobin, Shaikh; Mathur, Pradeep; Lahiri, Goutam; Srivastava, Ashwini (2013). "Biomimetic sensor for certain catecholamines employing copper(II) complex and silver nanoparticle modified glassy carbon paste electrode". Biosensors and Bioelectronics 39: 124–132. doi:10.1016/j.bios.2012.07.008 9.Sanghavi, Bankim; Srivastava, Ashwini (2011). "Simultaneous voltammetric determination of acetaminophen and tramadol using Dowex50wx2 and gold nanoparticles modified glassy carbon paste electrode". Analytica Chimica Acta 706: 246–254. doi:10.1016/j.aca.2011.08.040. 10.Sanghavi, Bankim; Srivastava, Ashwini (2011). "Adsorptive stripping differential pulse voltammetric determination of venlafaxine and desvenlafaxine employing Nafion–carbon nanotube composite glassy carbon electrode". Electrochimica Acta 56: 4188– 4196. doi:10.1016/j.electacta.2011.01.097.




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Application of Infra-Red Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama

APPLICATION OF INFRA-RED INFRA RED SPECTROSCOPY IN CORROSION INHIBITION STUDIES ,3 D.Lakshmi 1*,S.Rajendran 2,3 , and J.Sathiyabama 2,R, Joseph Rathis 4and S .Santhana Prabha4

1*Department of Chemistry, Chemistry, ,M.V.Muthiah Government Arts College for Women, Dindigul Dindigul-624001 , Tamilnadu, INDIA3 2

Department of Chemistry, G.T.N.Arts College, Dindigul-Tamilnadu, Dindigul Tamilnadu, INDIA

3

Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul women 624 005,Tamil ,Tamil Nadu, India. Email: [email protected] 4

PSNS College of Engineering and Technology, Dindigul, India

Abstract The corrosion inhibition efficiency of the inhibitor system phenolic compounds-Zn compounds 2+in controlling the corrosion of Al (6061) at pH 11 has been characterized by Fourier Transform Infra-red red Spectrocopy (FTIR)Technique The formulation consisting of 250 ppm of phenolic compounds and 50 ppm of Zn2+ reveals that a protective film consisting of Al3+ phenolic Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 18 Int J Nano Corr Sci and Engg 3(4)(2016) 181-203 Editors: Dr S Rajendran, A Christy Catherine Mary

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Application of Infra-Red Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama complex is formed on the anodic metal surface, and the exact position of an absorption band which also changes with the molecular environment Key words: phenolic compounds, corrosion, inhibition, aluminum, aqueous solution, zinc ion,

I.Introduction Infra red spectrum, the part of the electromagnetic spectrum between 4000 and 400 cm-1 is characteristic of the entire molecule. Many of the group absorptions vary over a wide range because the bands arise from complex interacting vibrations within the molecule. FTIR relies on the fact that the most molecules absorb light in the infra-red infra red region of the electromagnetic spectrum. This absorption corresponds specifically to the bonds present in the molecule. The frequency ranges are measured as wave numbers typically over the range 4000 – 600 cm-1. For a molecule to absorb IR, the vibrations or rotations within a molecule must cause a net change in the dipole moment of the molecule. The alternating electric field of the radiation interacts with fluctuations in the dipole moment of the molecule. If the frequency of the radiation matches with the vibrational frequency of the molecule then radiations will be absorbed causing a change in the amplitude of the molecular vibration,

Fig: 1 The absorption absorpt frequencies of functional groups Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 18 Int J Nano Corr Sci and Engg 3(4)(2016) 181-203 Editors: Dr S Rajendran, A Christy Catherine Mary

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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama

Table 1: Characteristics Functions Functional Class S-H thiols S-OR esters S-S disulfide C=S thiocarbonyl S=O sulfoxide sulfone sulfonic acid sulfonyl chloride sulfate

Characteristic Absorptions Sulfur Functions 2550-2600 cm-1 (wk & shp) 700-900 (str) 500-540 (wk) 1050-1200 (str) 1030-1060 (str) 1325± 25 (as) & 1140± 20 (s) (both str) 1345 (str) 1365± 5 (as) & 1180± 10 (s) (both str)

Phosphorous Functions 2280-2440 cm-1 (med & shp) 950-1250 (wk) P-H bending (O=)PO-H phosphonic acid 2550-2700 (med) P-OR esters 900-1050 (str) P=O phosphine oxide 1100-1200 (str) 1230-1260 (str) 1100phosphonate 1200 (str) 1200-1275 (str) phosphate phosphoramide Silicon Functions Si-H silane 2100-2360 cm-1 (str) Si-OR 1000-11000 (str & brd) Si-CH3 1250± 10 (str & shp) Oxidized Nitrogen Functions =NOH oxime 3550-3600 cm-1 (str) 1665± 15 945± 15 O-H (stretch) C=N N-O N-O amine oxide 960± 20 1250± 50 aliphatic aromatic P-H phosphine



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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama N=O nitroso nitro

1550± 50 (str) 1530± 20 (as) & 1350± 30 (s)

Table :2 Typical vibrational frequencies of functional groups BOND C-O C-O C-O N-H (Stretching) N-H (Bending) O-H C-N S-H

MOLECULE Alcohols, ethers, esters, carboxylic acids etc. Aldehydes, ketones, esters, carboxylic acids Amides Amines and amides Amines and amides Alcohols Amines Mercaptans

Wave number (cm -1) 1300-1000 1750-1680 1680-1630 3500-3100 1640-1550 3650-3200 1350-1000 2350

II.Hydrogen bonding Hydrogen Bonding can occur in any system containing a proton donor group(X-H) and proton acceptor group(Y) possessing lone pair of electrons. The common proton donor groups in organic molecules are carboxyl, hydroxyl, amine or amide groups Common proton acceptor atoms

are oxygen, nitrogen and the halogens. The strength of the Hydrogen Bond is at a

maximum when the proton donor group and the axis of the lone pair orbital are collinear. The strength of the Bond decreases as the distance between X and Y increases. Since the force constants of both the groups are altered by Hydrogen Bond the X-H stretching bands move to lower frequencies (longer wavelengths) and the H-X bending vibrations shift to a shorter wavelength. The change in frequency between “free” OH

absorption and bonded OH

absorption is a measure of the strength of the Hydrogen Bond. The from inter-molecular

broad

bands that result

bonding generally disappear at low concentrations .Intra-molecular



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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama hydrogen bonding is an internal effect and persists at very low concentrations give rise to sharp, well defined bands. The non Hydrogen Bonded or “free” OH of alcohols and phenols absorbs strongly in the 3700-3584 cm-1 region. Intermolecular hydrogen bonding increases as the concentrations of the solution increases, and additional bands start to appear at lower frequencies, 3550-3200 cm-1, at the expense of “free” hydroxyl band. By virtue of the electronegative nitrogen atom and the even more electronegative oxygen atom, the IR spectra indicate that intermolecular H-bonding may be present. The IR frequency bands

of

the

–OH

and

H–N

groups

having stretched

at

3368 cm−1 and

3198–

3071 cm−1 respectively. The FTIR spectrum of adsorbed protective layer formed on mild steel surface after immersion in 1 M HCl containing 300 ppm atenolol(2) The infrared spectrum of HPB indicates the presence of phenolic oxygen band and the characteristic bands due to benzimidazole nucleus: C=C aromatic groups, NH imine group and CN pyridil group. The bands at 3438 cm-1 and 3325 cm-1 are due to ν(O-H) and ν(N-H) stretching vibration frequencies, respectively. These bands appear closer to each other due to intra-molecular hydrogen bonding between the phenoxy hydrogen atom and one of the imine nitrogen atoms.(3) Intra-molecular hydrogen bonding reduces the carbonyl stretching absorption frequency from 1760 cm-1 to 1665 cm-1 (salicylic acid), whereas p- hydroxyl benzoic acid absorbs at 1680 cm-1. A strong intra molecular N—H···O hydrogen bond is a characteristic feature in many anthranilic acid complexes. The main intermolecular interactions are of the N—H----O/Br and O—H---O/Br types(4)



186

Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama 2,6-di-t-butylphenol, in which steric hindrance prevents hydrogen bonding, no bonded hydroxyl band is observed, not even in spectra of a meat sample.(5) Broad band at 3316.6 cm-1 is observed in the spectrum of TALE extract indicates –OH or N-H stretching vibration. a downshift from 3316 to 3406 cm-1, which is attributed to the change in the frequencies of hydroxyl and amino groups. The –C=O stretching frequency has increased from 1602 to 1628cm-1. This indicates that TALE has co-ordinated with Fe2+ through O atoms in -C=O stretching frequency. The result shows that TALE contains oxygen and nitrogen atoms in functional groups (O-H, N-H, C-O-C, C=O, C-H) and aromatic ring, which mainly bond with metal and protect mild steel from corrosion.(6) The shifts in the spectra of FTIR spectra of the RH extract and the corrosion product,indicate that the interaction between the extracts and mild steel occurred through the functional groups presents in them. Moreso, it can be affirmed that the functional group has coordinated with Fe2+ formed on the metal surface resulting in the formation of Fe2+ extract complex on the metal surface, which promotes the inhibition of the metal sample.(7) Thus IR is applied for detection and identification of different elements/ compounds in solving problems in the fields of forensics, medicine, oil industry, atmospheric industry, polymer degradation, pharmacology, etc. Among the more common spectroscopic methods used for the analysis is FTIR spectroscopy, where chemical bonds can be detected through their characteristic infra-red absorptions frequencies. Application of FTIR spectra in analyzing the protective formed on metal surface during the corrosion inhibition process is gaining momentum. The cleaned metal specimen is immersed in the environment which offers the maximum corrosion protection efficiency for a specified Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama period. A protective film is formed during this process. It is washed with distilled water and dried. A portion of the film is carefully scratched from the metal surface mixed with KBr and made into a pellet form. Then FTIR spectrum is recorded. This spectrum is compared with that of the pure inhibitor sample. The shift in the frequencies of the functional groups is noted. From these shifts, the formation of protective films on the metal surface is confirmed. III.Theory of FT-IR Fourier Transform Infrared (FT-IR) spectrometry was developed in order to overcome the limitations encountered with dispersive instruments. The main difficulty was the slow scanning process. A method for measuring all of the infrared frequencies simultaneously, rather than individually, was needed. A solution was developed which employed a very simple optical device called an interferometer. The interferometer produces a unique type of signal which has all of the infrared frequencies “encoded” into it. The signal can be measured very quickly, usually on the order of one second or so. Thus, the time element per sample is reduced to a matter of a few seconds rather than several minutes.



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Application of Infra-Red Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama

Fig : 2 Michelson interferometer Collimated light from a broadband infrared source passes into the optical system and impinges on a Beam Splitter that comprises a very thin film of germanium. Approximately 50% of the light passes through the film and is reflected back along its path by a fixed mirror, where half of the light intensity (25% of the original light intensity) is reflected by the same Beam Splitter, through the sample cell, to the infrared sensor. The other 50% fraction of the incident light is reflected at right angles to its incident path onto a moving mirror. Light from the moving mirror returns along its original path and half of the light intensity is transmitted through the Beam Splitter, through the sample cell, to the infrared sensor. As a result, 25% of the incident collimated light from the source reaches the sensor from the fixed mirror and 25% from the movable mirror. Now the path length of the two light beams beams striking the sensor will be different so there will be destructive and constructive interference. Actually, the system constitutes a form of the Michelson interferometer. As the movable mirror traverses it’s programmed path and constructive and destructive interference takes place, a series of maxima and minima signals will be monitored by the sensor. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 18 Int J Nano Corr Sci and Engg 3(4)(2016) 181-203 Editors: Dr S Rajendran, A Christy Catherine Mary

189

Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama It is also seen that the frequency of this waveform will be determined by the velocity of the moving mirror, which is experimentally controllable. This results in the interferometer actually taking a Fourier transform of the incoming signal. Thus an Interferogram is obtained from FTIR. IV. RESULTS AND DISCUSSION In the present study after the immersion period of 1 day in various environments, the specimens were taken out of the test solutions and dried. The Film formed on the surface was scratched carefully using a pointed glass rod and was thoroughly mixed with KBr so as to make uniform throughout. FTIR spectrum of the powder (KBr) pellet was recorded using Perkin-Elmer 1600 FTIR, spectrophoto meter with a resolving power of 4cm.

1.Analysis of FTIR spectra-PHENOL



190


Fig.4.1(a)FTIR spectrum of pure phenol The Broad Band at 3413 cm-1 observed in the spectrum of phenol indicates the –OH stretching vibration. A peak at 1596 cm-1 is attributed for the aromatic C=C stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1243 cm-1 [1].



191


Fig 4.1(b) FTIR Spectrum of the film formed on the surface of Aluminum immersed in phenol 250 ppm and Zinc 50 ppm at Ph11 The –OH stretching frequency has increased from 3413 cm-1 to 3426 cm-1. This shows that Al3+ has coordinated through oxygen atom of the –OH group in phenol. The C=O stretching frequency has increased from 1243 cm-1 to 1256 cm-1. So phenol has coordinated with Al3+ through the phenolic oxygen resulting in the formation of Al3+ phenol complex. The band at 612 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1404cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9].This indicates the presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. When Aluminum is immersed in this solution the Zn2+ phenol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ phenol complex is converted into Al3+ phenol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ phenol complex is formed on the anodic metal surface. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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2.Analysis of FTIR spectra - RESORCINOL

Fig4.2(a) FTIR spectrum of pure resorcinol The Broad Band at 3261 cm-1 observed in the spectrum of resorcinol indicates the –OH stretching vibration. A peak at 1609 cm-1 is attributed for the aromatic C=C stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1149 cm-1 [1].



193


Fig.4.2(b)FTIR Spectrum of the film formed on the surface of Aluminium immersed in resorcinol 250 ppm and Zinc 50 ppm at pH11 The –OH stretching frequency has increased from 3261 cm-1 to 3431 cm-1.This shows that Al3+ has coordinated through oxygen atom of the –OH group in resorcinol. The aromatic C=C stretching frequency has shifted from 1609 cm-1 to 1594 cm-1 which indicates that resorcinol has coordinated with Al3+ through π electrons. The C=O stretching frequency has decreased from 1149 cm-1 to 1112 cm-1. So resorcinol has coordinated with Al3+ through the phenolic oxygen resulting in the formation of Al3+ resorcinol complex. The band at 614 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1405 cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9]. This indicates the presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. When Aluminium is immersed in this solution the Zn2+ resorcinol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ resorcinol complex is converted into Al3+ Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama resorcinol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ resorcinol complex is formed on the anodic metal surface. 3.Analysis of FTIR spectra – ALPHA NAPHTHOL

Fig.4.3(a)FTIR spectrum of pure alpha naphthol The Broad Band at 3259 cm-1 observed in the spectrum of alpha naphthol indicates the –OH stretching vibration. A peak at 1585 cm-1 is attributed for the aromatic C=C stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1268 cm-1 [1].



195


Fig.4.3(b) FTIR Spectrum of the film formed on the surface of Aluminum immersed in alpha naphthol 250 ppm and Zinc 50 ppm at pH11 The –OH stretching frequency has increased from 3259 cm-1 to 3427 cm-1.This shows that Al3+ has coordinated through oxygen atom of the –OH group in alpha naphthol. The aromatic C=C stretching frequency has shifted from 1585 cm-1 to 1594 cm-1 which indicates that resorcinol has coordinated with Al3+ through π electrons. The C=O stretching frequency has decreased from 1268 cm-1 to 1261 cm-1. So alpha naphthol has coordinated with Al3+ through the phenolic oxygen resulting in the formation of Al3+ alpha naphthol complex. The band at 615 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1405 cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9]. This indicates the presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. When Aluminum is immersed in this solution the Zn2+ alpha naphthol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ alpha naphthol complex is converted into Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama Al3+ alpha naphthol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ alpha naphthol complex is formed on the anodic metal surface. 4.Analysis of FTIR spectra – BETA NAPHTHOL

Fig4.4(a)FTIR spectrum of pure beta naphthol The Broad Band at 3243 cm-1 observed in the spectrum of beta naphthol indicates the –OH stretching vibration. A peak at 1628 cm-1 is attributed for the aromatic C=C stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1277 cm-1 [1].



197


Fig.4.2(b) FTIR Spectrum of the film formed on the surface of Aluminium immersed in beta naphthol 250 ppm and Zinc 50 ppm at pH11 The –OH stretching frequency has increased from 3243 cm-1 to 3427 cm-1.This shows that Al3+ has coordinated through oxygen atom of the –OH group in beta naphthol. The aromatic C=C stretching frequency has shifted from 1628 cm-1 to 1595 cm-1 which indicates that beta naphthol has coordinated with Al3+ through π electrons. The C=O stretching frequency has decreased from 1277 cm-1 to 1256 cm-1. So beta naphthol has coordinated with Al3+ through the phenolic oxygen resulting in the formation of Al3+ beta naphthol complex. The band at 614 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1404 cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9]. This indicates the presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama When Aluminium is immersed in this solution the Zn2+ beta naphthol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ beta naphthol complex is converted into Al3+ beta naphthol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ beta naphthol complex is formed on the anodic metal surface. 5.Analysis of FTIR spectra – o.nitro phenol

Fig.5.1(a)FTIR spectrum of pure o-nitro phenol The Broad Band at 3430 cm-1 observed in the spectrum of o-nitro phenol indicates the –OH stretching vibration. A peak at 1613 cm-1 is attributed for the –N=O stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1140 cm-1 [1]. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


199


Fig.5.2(b) FTIR Spectrum of the film formed on the surface of Aluminium immersed in onitro phenol 250 ppm and Zinc 50 ppm at pH11 The –OH stretching frequency has decreased from 3430 cm-1

to 3429 cm-1. The -N=O

stretching frequency has shifted from 1613 cm-1 to 1594 cm-1 which indicates that o-nitro phenol has coordinated with Al3+ through the oxygen atom of the –N=O group in o-nitro phenol . . The C=O stretching frequency has decreased from 1140 cm-1 to 1120 cm-1. So o-nitro phenol has coordinated with Al3+ through the nitro oxygen resulting in the formation of Al3+ o-nitro phenol complex which may be due to the intra molecular hydrogen bonding of o-nitro phenol. The band at 615 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1405 cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9]. This indicates the



200

Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. When Aluminium is immersed in this solution the Zn2+ o-nitro phenol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ o-nitro phenol complex is converted into Al3+ o-nitro phenol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ o-nitro phenol complex is formed on the anodic metal surface. 6.Analysis of FTIR spectra – p – nitro phenol

Fig.6.1(a)FTIR spectrum of pure p-nitro phenol The Broad Band at 3325 cm-1 observed in the spectrum of p-nitro phenol indicates the –OH stretching vibration. A peak at 1590 cm-1 is attributed for the –N=O stretching vibration. The C=O stretching frequency of phenolic compound occurs at 1105 cm-1 [1].



201


Fig.6.2(b) FTIR Spectrum of the film formed on the surface of Aluminium immersed in pnitro phenol 250 ppm and Zinc 50 ppm at pH11 The –OH stretching frequency has increased from 3325 cm-1

to 3427 cm-1. This shows that

Al3+ has coordinated through oxygen atom of the –OH group in p-nitro phenol . The -N=O stretching frequency has shifted from 1590 cm-1 to 1593 cm-1.. The C=O stretching frequency has increased from 1105 cm-1 to 1121 cm-1. So p-nitro phenol has coordinated with Al3+ through the phenolic oxygen resulting in the formation of Al3+ p-nitro phenol complex. The band at 616 cm-1 may be due to the metal-oxygen stretching vibration and the band at 1404 cm-1 may be due to inplane vibrations of –OH group in Zn(OH)2 [8,9]. This indicates the presence of Zn(OH)2 on the metal surface. There is also possibility of formation of Al(OH)3 precipitate on the metal surface. When Aluminum is immersed in this solution the Zn2+ p-nitro phenol complex diffuses from the bulk of the solution towards the metal surface. Zn2+ p-nitro phenol complex is converted into Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama Al3+ p-nitro phenol complex on the metal surface. Zn2+ is released and Zn(OH)2 is formed. Thus a protective film consisting of Al3+ p-nitro phenol complex is formed on the anodic metal surface. CONCLUSION: A protective film consisting of Al3+ phenolic complex is formed on the anodic metal surface. Due to intra-molecular hydrogen bonding o-nitro phenol has coordinated with Al3+ through the nitro oxygen whereas the p-nitro phenol has coordinated with Al3+ through the phenolic oxygen due to the absence of hydrogen bonding ACKNOWLEDGEMENT The authors are thankful to their management for their help and managements.

REFERENCES [1]. Study of corrosion inhibition properties of novel semicarbazones on mild steel in acidic solutions Dr. Rathika Govindasamy, Swetha Ayappan j . chil. chem.soc. 60 (1) (2015) [2]. Studies on the inhibition of mild steel corrosion in hydrochloric acid solution by atenolol drug G.Karthik.M.sundaravadivelu Egyptian Journal of Petroleum25, (2), (2016), 183–191 [3]. org 2-(o-Hydroxyphenyl)Benzimidazole as a New Corrosion Inhibitor for mild Steel in Hydrochloric Acid Solution Abboud1, B. Hammouti A. Abourriche1, B. Ihssane1, A. Bennamara1, M. Charrouf1 Int. J. Electrochem. Sci., 7 (2012) 2543 - 2551 International Journal of Electrochemical Science



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Application of Infra-Red Spectroscopy In Corrosion Inhibition Studies D.Lakshmi ,S.Rajendran and J.Sathiyabama [4]. Spectroscopic and Thermal studies of Anthralinic acid (Vitamin l)-with Br and Cl V. Susindrana,c, S. Athimoolamb and S. Asath Bahadura Journal of Chemical and Pharmaceutical Research, 4(10) 2012:4628-4636. [5]. Spectrometric Identification of Organic Compounds , R.M.Silverstein , F.X.Webster John Wiley and sons sixth edition 136 (2011). [6] Anti-Corrosion Inhibition of Mild Steel in 1M Hydrochloric Acid solution by using Tiliacora accuminata leaves Extract R. Karthik1, P. Muthukrishnan, Shen-Ming Chen B. Jeyaprabha, P. Prakash Int. J. Electrochem. Sci., 10 (2015) 3707 – 3725.

[7] Corrosion Inhibition and Adsorption Characteristics of Rice Husk Extracts on Mild Steel Immersed in 1M H2SO4 and HCl Solutions mK. K. Alaneme1,Y. S. Daramola, S. J. Olusegun, A. S. Afolabi Int. J. Electrochem. Sci., 10 (2015) 3553 - 3567 [8]. I.Sekine and Y.Hirakawa Corr 42-276 (1986). [9]. S.Rajendran , B.V.Apparao and N.Palaniswamy , Bull. Electrochem 12 – 15 (1996).




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Comparative Analysis of Corrosion rosion Inhibition Studies on o Various Metals in Oil Well Water using Trisodiums Phosphate as a Inhibitor S.Anusuya and S.Devi Meenakshi.

COMPARITIVE ANALYSIS OF CORROSION CORROSION INHIBITION STUDIES ON VARIOUS METALS IN OIL WELL WATER USING TRISODIUM PHOSPHATE AS INHIBITOR 1

S.Anusuya Anusuya and 2S.Devi Meenakshi s

Department of Chemistry and Physics P Nadar Saraswathi College of Arts & Science,Theni. E-mail:[[email protected] and [email protected]] ABSTRACT The inhibition efficiency of an aqueous aqueous solution of Tri Sodium Phosphate (TSP (TSP) in controlling corrosion of SS 18/8 immersed in petr200 ppm of TSP offers 98% corrosion inhibition efficiency in the absence of chloride system. Polarization study reveals that an aqueous solution of simulated oil well Solution and TSP system controls the cathodic reaction predominantly. The results obtained showed some magnitude of corrosion susceptibility for the stainless steel. Effective corrosion inhibition was also exhibited on the tested sample. sample Keywords: Simulated oil well water; water Stainless steel, galvanized steel, mild steel; corrosion inhibition; TSP (Tri Sodium phosphate); phosphate electrochemical polarization studies. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. 1. Introduction Facilities for the production of oil and gas often have to cope with corrosive environments. The difficulties in protecting plant become more acute when the facilities are in a hostile and remote offshore setting. Assessment of the potential corrosion for a new facility may lead to the choice of using corrosion resistant alloys or using carbon steels with corrosion inhibitors.[1-8] For existing, ageing installations, treatment of the produced fluids with corrosion inhibiting chemicals is often the only feasible option. The main mechanisms for internal corrosion of pipelines are aqueous corrosion caused by soluble corrosive gas, such as carbon dioxide, hydrogen sulphide, or oxygen, and corrosion influenced by microorganisms. The oil water can arise from being part of the original reservoir products (formation water) or from water injection used to increase pressure. Corrosion inhibitors work by forming a protective film on the metal preventing corrosive elements contacting the metal surfaces. Then we use the metals like stainless steel 18/8. The term "18-8" is used interchangeably to characterize fittings made of 302, 302HQ, 303, 304, 305, 384, XM7, and other variables of these grades with close chemical compositions. There is little overall difference in corrosion resistance among the "18-8" types, but slight differences in chemical composition do make certain grades more resistant than others do against particular chemicals or atmospheres. "18-8" has superior corrosion resistance to 400 series stainless, is generally nonmagnetic, and is harden able only by cold working. And I use mild steel. The use of mild steel as construction material in industrial sectors has become a great challenge for corrosion engineers or scientists nowadays. Most of the acidic industrial applications such as refining crude oil, acid packing, industrial cleaning, acid descalings, and oilwell acid in recovery and petrochemical processes use mild steel as their material. Galvanizing steel also used as the welding industries and I used the inhibitor like trisodium phosphate (Na3Po4) used as the cleaning agent, insoluble in ethanol and also attain removes. All the three Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


204 204

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. sample steels are in the petrol oil water contains a sodium chloride (NaCl) 3.5g was weighed and 0.305g of calcium chloride solution (Cacl2) and 0.186g of magnesium chloride (Mgcl2) make 500ml in standard measuring flas (SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution was mixed with a fraction of a second

[9-16] .

All the samples are

exampled in the polarization studies and the electro chemical studies. These expected good reaction will be produced. 2. MATERIALS AND METHODS Stimulated Petrol Oil Solution A saturated solution of sodium chloride(NaCl) 3.5g was weighed and 0.305g of Calcium chloride solution(Cacl2) and 0.186g of magnesium chloride(Mgcl2) make 500ml in standard measuring flask(SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution was mixed with a fraction of a seconds. Evolve the hydrogen sulphide smell (H2S) to form petrol oil water made three set of the solutions. [17-30] Metal specimens SS 18/8:18% of chromium and 8%of nickel was used and the mild steel, galvanized steel was used. Potentiometric studies Polarization studies were carried out in a CHI-Electrical workstation with impedance, Model 660A.A three electrode cell assemblies was used. The working electrode was one of the three metals. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr) corrosion current (Icorr) and Tafel slopes (anodic= ba and cathodic= bc) were calculated Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. .[31-37]

Electro chemical studies A three electrodes cell system containing working electrode (mild steel coupon) of a 1 cm2 exposed area, saturated calomel electrode as a reference and the a platinum electrode as auxiliary were used. All electrochemical experiments were performed at room temperature (25 ± 2°C) in 2M HCl electrolyte solution with and without extracted inhibitor using Gill AC potentio stat manufactured by ACM Instruments. Three different electrochemical tests were conducted, linear polarization resistance (LPR), Potentiodynamic scans (cyclic sweep polarizations, CS) and electrochemical AC impedance spectroscopy (EIS). A linear polarization test was carried out by a scan from approximately -10mV to +10mV with respect to working electrode rest potential. The cyclic sweep polarization also took in consideration open circuit potentials of working electrode and started at a relatively cathodic potential and scanned towards the anodic direction, E = ± 300 mV with a scan rate of 1mV/s. EIS measurements were performed using AC signal amplitude of 20 mV peak to peak in the frequency range of 0.1 Hz to 1kHz. The inhibition efficiency (IE) was determined using the equation IE =(I-Ii)/Ix100………….(1) Where I and Ii are the corrosion current densities without and with inhibitor, respectively. 3. Experimental Section 3.1 Inhibitor preparation



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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. Trisodium phosphate were prepared by Trisodium phosphate is produced by neutralization of phosphoric acid using sodium hydroxides, often with sodium carbonate. Carbonate can only produce disodium phosphate [37-41] Na2CO3 + H3PO4 → Na2HPO4 + CO2 + H2O Na2HPO4 + NaOH → Na3PO4 + H2O The inhibitor efficiency could be measured by the follow equation Ef=Ri-R0/R0x100………………… (2) Where, Ef is inhibitor efficiency (percentage), RI is corrosion rate of metal with inhibitor and Ro is corrosion rate of metal without inhibitor.



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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. 3.2 Electrochemical Measurements Electrochemical studies were carried out using conventional three electrode with larger area platinum foil as counter electrode and saturated calomel electrode (SCE)as reference electrode. Electrochemical analyzer (1280B) interfaced with an IBM computer was used for measurements. The polarization studies were made after the specimen attained a steady state potential. The polarization was carried out using a software from a cathodic potential of -0.2V to an anodic potential +0.2V with respect to the corrosion potential at sweep rate of0.5 mV/s. E versus log I curves were plotted .The linear TAFEL segments of the anodic and cathodic curves were extra plotted to corrosion potential to obtain the corrosion current densities. The corrosion inhibition efficiency was evaluated from the measured icorr values using the relationship: IE (%) =icorr-icorr”/Icorr0x100 ……..

(3)

Where icorr and icorr” are the corrosion current densities without and with the addition of various concentrations of the inhibitor, respectively .For linear polarization measurements a sweep from -0.02 to +0.02V versus open circuit potential at a sweep rate of 0.5mV/s was used .The polarization resistance, Rp, is obtained as the slope of the””h versus I”” curve at the vicinity of corrosion potential Ecorr. The corrosion inhibition efficiency was evaluated from the measured icorr..This DC method of pertubution yields Rp which includes the solution resistance Rs. The inhibition efficiencies were evaluate from the polarization resistance, Rp values are IE%=Rp”- Rp/ Rp”x100 ……..

(4)

Where Rp and Rp” are the polarization resistances without and the addition of inhibitors ,respectively software was used for data acquisition and analysis of interfacial impedence.AC signals of 10 mV amplitude and frequency spectrum from 100 KHz to 0.01Hz was impressed and the Nyquist representations of the impedance data were analyzed with View software. The charge transfer resistance Rcts is obtained as the diameter of the Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. semi circle of Nyquist curve .By doing so, in this AC method of perturbations, the contributions from the solution resistance are eliminated. The inhibition efficiency was evaluated from the measured charge transfer resistance Rct values as IE%=Rct”-Rct/Rct”x100 ………

(5)

Where Rct and Rct” are the charge transfer resistance values in the absence and presence of inhibitors, respectively. The interfacial double layer capacitance Cdl is obtained from the frequency of the point having maximum imaginary component (i.e.the point corresponding to the top of the semi circle) as Cdl=1/2 fmaxRct

…………..

(6)

Where “”fmax””corresponds to the frequency having maximum imaginary component 4. Results and Discussion 4.1 Potentiodynamic polarization study Polarization studies were carried out in a CHI –Electrochemical workstation with impedance, Model 66 Figure.1.Three electrode system

A three-electrode cell assembly was used. The three electrode assembly is shown in Scheme 2. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion



205 205

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic = bc) were calculated. Stainless steel The result of the stainless steel in the blank solution the value of Ecorr is the (-152) and presence of Trisodium phosphate Ecorr (-109)


Figure.3.Stainless steel in trisodium Phosphate

Mild steel The result of the mild steel in the values of the blank solution Ecorr (-550) and the presence of the trisodium phosphate solution Icorr (-554).



206 206

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi.

Figure.4. Mild steel in blank

Figure.5.mild steel in the trisodium Phosphate

Galvanized steel The result of the galvanized steel in the values of the blank solution Ecorr (-610) and the presence of the trisodium phosphate solution Icorr (-620).s


Figure.7.galvanized steel in trisodium phosphate

4.2.ACImpedence



207 207

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. The effect of trisodium phosphate on the behavior of stainless steel in petroleum oil water is presented in the form of Nyquist plots on figure.3. The curves show a similar type of Nyquist plots for stainless steel in the presence ofs trisodium phosphate. Values of impedance parameters of stainless steel in both media are presented in The EIS technique has been one of the most used methods to report the mechanism of corrosion and corrosion protection of metals and alloys in aggressive media [17-21]. The Nyquist plots obtained for the pipeline steel electrodes at an opencircuit potential after their immersion solution Table.1. The impedance measurement was performed using AC signals with 10 mV amplitude for the frequency range from 100 kHz to 0.01 Hz at corrosion potential. Solatron electrochemical analyzer model (1280 B) interfaced with IBM computer along with Corrware and Z plot softwares were used for data acquisition and analysis. EIS Analyzer software was used to fit the experimental results of EIS measurements Table.1.Electrochemical Potentiodynamic Polarization Studies of Stainless steel in the presence of trisodium phosphate SYSTEM Ecorr

Bc

b’c

LPR

Icorr

Ref

SS 18/8

1/5.740

1/5.139

4375896

9.133X10-9

1933

-152

Cdes

Z

Phase angle

3.746

78.24

3.946

75.67

4.605

22.15

106.9 1826.1 SS+TSP

-109

1/5.991

1/3.793

10544308

-9

4.214X10

-

4244 0 =4244

MS

-550

1/4.823

1/4.957

47110

9.437x10-7

-

40990 15030=

-

25960 MS+TSP

-554

1/4.824

1/5.010

9954

4.42x10-6

8884



208 208

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. 2779=6105 GS

-610

1/7.588

1/11.506 4590

4.961x10-6

-620

1/4.091

1/9.147

1988

1.652x10-5

3.946

17.64

-

2.343

35.54

-

2.32

31.5

215 30.5=184.5

GS+TSP

-

216 33=183

Stainless steel Electrochemical TAFEL results in the stainless steel are absence and presence of trisodium phosphate.

Figure.8.stainless steel in blank

Figure.9.stainless steel in trisodium Phosphate

Mild steel Electrochemical TAFEL results in the mild steel in absence and presence of trisodium phosphate



209 209

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi.

Figure.10.Mild steel in blank

Figure.11.Mild steel in trisodium phophate

Galvanized steel The result of the galvanized steel in the values of the blank solution Ecorr (-610) and the presence of the trisodium phosphate solution Icorr (-620).s


Figure.13.galvanized steel in trisodium Phosphate

5. Conclusion



210 210

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. The results obtained from present study showed that disodium phosphate is a good inhibitor and acted as a mixed-type inhibitor in petroleum oil water. Absorption of stainless steel, mild steel, galvanized steel in blank and in trisodium phosphate obey in polarization and electrochemical studies. The presence of trisodium phosphate inhibits the corrosion process on the stainless steel. Produces a perfect result environmentally acceptable organic corrosion inhibitor was used in the stainless steel perfect. 6. Reference [1] Sastri, V. S., "Corrosion inhibitors", John Wily & Sons. Inc.(1998). [2] Mansfeldm, F., Kendig, M. W. and Lorenz, W. J., (1985), "Corrosion Inhibition in Neutral, Aerated Media", J. Electronchem Soc., Vol. 132, NO.2, P290-296. [3] Wang D, Li Shuyuan.Y, Wang, M., Xiao, H., Chen, Z,"Theoretical and Experimental Studies of Structure and Inhibition Efficiency of Imidazoline Derivatives", Corrosion Science, Vol. 41, (1999), P1911-1919. [4] Campbell, S., Jovancicevic, V., "Corrosion Inhibitor Film Formation Studied by ATR-FTIR", Corrosion/99, (1994) Paper No.484. [5] Videm, K. and Kvarekvaal, J., Corrosion/96, (1996), Paper No.484. [6] Crolet, J., Thevenot, N. and Nesic, S., Corrosion/96(1996) Paper No.4. [7] Nesic, S., Thevenot, N., Crolet, J. and Drazic, D., Corrosion/96, (1996) Paper No.3. [8] Heuer, J.K. and Stubbins, J.F. (1998), Corrosion, 54, P566.



211 211

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. [9] Schmitt, G., Gudde, T., and Strobel-Effertz, E., "Fracture Mechanical Properties of CO2 Corrosion. [10]J.Sathyabama,S.Rajendran,J.Arockiaselvi&J.eya sundari, the open corrosion journal 2(2009)76. [11]V.Kumar, corrosion rev.16 (1998)317. [12]P.Gareces, M.C.Andrade, A.Saez&M.C.Alonso, corrosio science. 47 (2005) 289. [13]M.Moreno, W.morris, M.G.Alvarez and G.S.Duffo, corrosion science 46 (2004).268. [14]X.Zhow, H.Y.Yang, F.H.wang, corrosion science protection technology 22 (4) 2010 (43. [15]P.Ghods, O.B.Isgaor, G.A.Mcrae, G.P.GV, corrosion science 52 (5) (2010) 1649. [16]S.Agnesia Kanimozhi & S.Rajendran, International journal of electro chemical science, 4 (2009)353. [17]Emeka E.Oguzie, corrosion science, 50 (11) (2008) 2993. [18] Sastri, V. S., "Corrosion inhibitors", John Wily & Sons. Inc, (1998). [19] Mansfeldm, F., Kendig, M. W. and Lorenz, W. J., (1985), “Corrosion Inhibition in Neutral, Aerated Media", J. Electronchem Soc., Vol.132, NO2, P290-296. [21] Wang D., Li Shuyuan, Y., Wang, M., Xiao, H, Chen Z., “Theoretical and Experimental Studies of Structure and Inhibition Efficiency of Imidazoline Derivatives", Corrosion Science, Vol. 41, (1999), P1911-1919.



212 212

Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. [22]Campbell, S., Jovancicevic, V, "Corrosion Inhibitor Film Formation Studied by ATR-FTIR", Corrosion/99, (1999) .Paper No.484. [23] Videm, K. and Kvarekvaal, J., Corrosion/96, (1996) Paper No.1. [24] Crolet, J., Thevenot, N. and Nesic, S., Corrosion/96, (1996) Paper No.4. [25] Nesic, S., Thevenot, N., Crolet, J. and Drazic, D., Corrosion/96, (1996) Paper No.3. [26] Heuer, J.K. and Stubbins, J.F., (1998), Corrosion, 54, P566. [27] Schmitt, G., Gudde, T., and Strobel-Effertz, E., "Fracture Mechanical Properties of CO2 Corrosion Product Scales and Their Relation to Localized Corrosion", Corrosion/96,(1996 ) Paper No.9.s [28] Kowata, K. and Takahashi, K., “Interaction of Corrosion Inhibitor with Corroded Steel Surface", corrosion/96, (1996) Paper No.219. [29] Walter, G.W., (1991), Corrosion Science, Vol. 32. No.10 p1041. [30] Tan, Y.J., Bailey, S. and Kinsella, B., (1996), Corrosion Science, Vol. 38, No.9, pp 1545. [31] Hackerman N. and Hurd R. M., (1962), Proc. Int. Congress of Metallic Corrosion, London, Butterworths, P 166. [32] EM. Sherif, S.-M, Park, J, Electrochemical. Soc., 152 (2005) B205. [33] N.A. Al-Mobarak, Int. J, Electrochemical. Sci, 3 (2008) 666. [34]Byoung-Yong Chang, Su-Moon Park, Annual Review of Analytical Chemistry, 13 (2010)20. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Comparative Analysis of Corrosion Inhibition Studies on Various Metals in Oil Well Water using Trisodiums Phosphate as Inhibitor S.Anusuya and S.Devi Meenakshi. [35] Abdel Salam Hamdy, E. El-Shenawy, and T. El-Bitar, Int. J, Electrochemical. Sci., 7 (2012) 2832. [36] El-Sayed M. Sherif, A.A. Almajid, A.K. Bairamov, Eissa Al-Zahrani, Int. J, Electrochemical. Sci., 7 (2012) 2796. [37] F. Mansfeld, S. Lin, S. Kim and H. Shih, Corros. Sci., 27s(1987) 997. [38]J.I. Bregman, ‘Corrosion Inhibitors’, (1963), London, Collier MacMillan Co. [39] G.G. Eldredge, J.C. Warner, ‘The Corrosion Handbook’, (ed. H.H. Uhlig), (1948), 905, New York, Wiley.s [40] C.C. Nathan, ‘Corrosion Inhibitors’ (1973), Houston, Texas, National Association of Corrosion Engineers (NACE). [41] N. Putilova, S.A. Balezin, V.P. Barannik, ‘Metallic Corrosion Inhibitors’, (1966), London, Pergamon Press.




214 214

Application off Electrochemical Studies S in Corrosion Inhibition off Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi

APPLICATION OF ELECTROCHEMICAL STUDIES IN CORROSION INHIBITION OF STAINLESS STEEL 18/8 IN OIL WELL WATER USING TRISODIUM PHOSPHATE AS INHIBITOR 1

M.Abinaya Abinaya and 2S.Devi meenakshi

Department Of O Chemistry and Physics Nadar Saraswathi College of Arts & Science, Theni. E-mail:[[email protected] and [email protected]] ABSTRACT In the work, EIS and Tafal fal techniques were used to study the corrosion inhibitor performance performanc of stainless steel 18/8 was evaluated evaluate using trisodium phosphate as inhibitor in petroleum oil water medium. The experimental results show that the corrosion product layer without out inhibitor is non nonprotective but in presence of inhibitor TSP, Tafel analysis suggest that the mostpossible wayto Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


216

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi decrease the corrosion rates could result from the effect of blocking the active sites on the metal surface by adsorbed TSP. From EIS, it is shown that with an increase in the inhibitor concentration, the double layer capacitance and inhibitor film capacitance decrease sharply, whilst the solution resistance in the pores increases. The analysis shows that the formation of a very dense inhibitor film on the metal surface rather than an increase in the corrosion product film thickness. This may explain both the decrease of charge transfer resistance and the decrease of film capacitance. The results obtained showed some magnitude of corrosion susceptibility for the stainless steel. Effective corrosion inhibition was also exhibited on the tested sample. Keywords: Stainless steel 18/8, corrosion, trisodiumphosphate, petroleumoilwater, polarization, inhibition. 1. Introduction In oil and gas production industry, internal corrosion of carbon steel pipeline is a wellknown phenomenon and a severe prsoblem, and inhibition is the most cost effective and flexible method of corrosion control. Adsorption of an organic inhibitor on a metal surface is physical or electric charge to the Metal surface forming a coordinate bond.Many researchers worked on corrosion inhibition studies using the metals like stainless steel Galvanized iron steel, Stainless steel 18/8.[1-8] etc.,. Therefore, knowledge of the mechanism of a metal on corrosion inhibition process is highly desirable in the design and proper selection of inhibitors. Inhibitors can interfere with the anodic or cathodic reaction, and can form a protective barrier on the metal surface against corrosive agents or can work by a combination of these actions. For application in the petroleum industry, organic inhibitors containing nitrogen (amines) are often used because of their effectiveness and availability. When a corrosion inhibitor is added to a system, adsorption of inhibitor molecules at the metal-solution interface occurs and this is accompanied Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


217

Application off Electrochemical Studies S in Corrosion Inhibition off Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi by a change in n potential difference between the metal electrode and the solution due to the nonnon [9-24] uniform distribution of electric charges at the interface inter Many researchers have been working

on the performance and mechanisms of the inhibitors based on the test resu results lts in small small-scale laboratory systems. The studies of Mansfield (1985) point out that interface inhibition presumes a strong interaction between the corroding corrod substrate and the inhibitor .The The two main types of the adsorption of an organic inhibitor on a metal me 304 austenite steel and its contains 18% of chromium,8% of a nickel.Surfaces Surfaces are physical or electric

charge to the metal surface, forming a coordinate-type coordinate bond. It is nonmagnetic steel which cannot be hardened by heat treatment, but instead. Must be cold worked to obtain higher tensile strengths. The 18% minimum chromium content provides corrosion and oxidation resistance. The alloy's metallurgical characteristics are established primarily by the nickel content (8% mm.), which also extends resistance resista to corrosion caused by reducingchemicals.Organicinhibitor like trisodium phosphate

take i did my project. It’s helpful at medicinal field and it’s have a

many properties [25-27].Trisodium phosphate (TSP) is the inorganic compound with the chemical formula Na3PO4.

Figure.1.TSP [Trisodium Trisodium phosphate] It is a white, granular or crystalline solid, highly soluble in water producing an alkaline solution. Trisodium phosphate inhibit a corrosion in petroleum water contains a sodium sulphite and



232

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi concentrated HCl.Inhibits a pipeline corrosion, Effective corrosion inhibition was also exhibited on the tested sample. Stainless steel also known as iron steel. 2. MATERIALS AND METHODS Stimulated Petrol Oil Solution A saturated solution of sodium chloride (NaCl) 3.5g was weighed and 0.305g of calcium chloride solution(CaCl2)and 0.186g of magnesium chloride(MgCl2) make 500ml in standard measuring flask(SMF) and add Sodium sulphite 0.03g and 2ml of concentrated hydro chloric acid solution was mixed with a fraction of a seconds. Evolve the hydrogen sulphide smell (H2S) to form petrol oil water.

Metal specimens SS 18/8:18% of chromium and 8%of nickel was used in the present study. Electrochemical studies Polarization studies were carried out in a CHI-Electrical workstation with impedence, Model 660A.A three electrode cell assembly was used. The working electrode was one of the three metals. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosioncurrent (Icorr) and Tafel slopes (anodic=ba and cathodic=bc) were calculated.[28-37]

3. Experimental Section 3.1Inhibitor preparation Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


233

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi Trisodium phosphate (Sodium phosphate tribasic) pH of Trisodium phosphate 1% solution is 12 it is very basic, and the solution is sufficiently alkaline. Trisodiumphosphates was weighed 0.05g and add to the oil well water solution.[38-42]

3.2 Electrochemical Measurements Electrochemical studies were carried out using conventional three electrode with larger area platinum foil as counter electrode and saturated calomel electrode (SCE) as reference electrode.Electrochemical analyser (1280B) interfaced with an IBM computer was used for measurements.The polarization studies were made after the specimen attained a steady state potential. The polarization was carried out using a corrware software from a cathodic potential of -0.2V to an anodic potential +0.2V with respect to the corrosion potential at sweep rate of0.5 mV/s.E versus log I curves were plotted .The linear Tafel segments of the anodic and cathodic curves were extraplotted to corrosion potential to obtain the corrosion current densities.The corrosion inhibition efficiency was evaluated from the measured icorr values using the relationship: IE (%) =icorr-icorr”/Icorr0x100

(1)

Where icorr andicorr” are the corrosion current densities without and with the addition of various concentrations of the inhibitor, respectively. For linear polarization measurements a sweep from -0.02 to +0.02V versus open circuit potential at a sweep rate

of 0.5mV/s was used .The

polarization resistance ,Rp,is obtained as the slope of the ””h versus I”” curve at the vicinity of corrosion potential Ecorr. The corrosion inhibition efficiency was evaluated from the measured icorr..This DC method of pertubution yields Rpwhich includes the solution resistance Rs, The inhibition efficiencies were evaluate from the polarization resistance, Rp values are Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


234

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi IE%=Rp”- Rp/ Rp”x100

(2)

Where RpandRp” are the polarization resistances without and the addition of inhibitors, respectively plot software was used for data acquisition and analysis of interfacial impedances.AC signals of 10 mV amplitude and a frequency spectrum from 100 KHz to 0.01Hz was impressed and the Nyquist representations of the impendencedata wereanalyzed with Viewsoftware. The charge transfer resistance Rct is obtained as the diameter of the semi-circle of Nyquist curve .By doing so, in this AC method of perturbations, the contributions from the solution resistance are eliminated.The inhibition efficiency was evaluated from the measured charge transferor resistance Rct values as IE%=Rct”-Rct/Rct”x100

(3)

Where Rct and Rct” are the charge transfer resistance values in the absence and presence of inhibitors,respectively.The

interfacial double layer capacitance Cdl is obtained from the

frequency of the point having maximum imaginary component (i.e.the point corresponding to the top of the semi-circle)as Cdl=1/2 fmaxRct

(4)

Where “”fmax””corresponds to the frequency having maximum imaginary component.[42]



235

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi

Figure.2.Electrochemical parameters

4. Results and Discussion 4.1 Potentiodynamic polarization study Polarization studies were carried out in a CHI –Electrochemical workstation with impedance, Model660A. A three-electrode cell assembly was used. The three electrode assembly is shown in Scheme 2. The working electrode was mild steel. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr) and Tafel slopes (anodic = ba and cathodic = bc) were calculated. The potentiodynamic polarization curves of stainless steel in oil water contains 3.5g of NaCl and 0.305g of CaCl2 and 0.186 MgCl2With addition of trisodium phosphate(Na3PO4) extracts affects both anodic anodic dissolution of steel cathodic reduction reactions indicating that the extracts could be classified as mixed type inhibitor. The corrosion kinetic parameters such as corrosion potential(Ecorr),corrosion current density (Icorr),anodic Tafel slope (ba) and cathodic Tafel slope (bc)deduced from the house for oil petrol water are in given Table -1.The values of the stainless steel in blank Ecorr(-152),and presence of Trisodium phosphate Ecorr(-109), and the value Icorr in blank (9.133x10-9) and in Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


236

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi presence of Trisodium phosphate the Icorr value is (4.214x10-9). Then the LPR values are in blank is (4375896), in the presence of trisodium phosphate is(10544308).in the mixed inhibitor.


Figure.4.Stainless steel in trisodium

4.2. AC Impedence The effect of trisodium phosphate on the behavior of stainless steel in petroleum oil water is presented in the form of Nyquist plots on figure.3. The curves show a similar type of Nyquist plots for stainless steel in the presence of trisodium phosphate. Values of impedence parameters of stainless steel in both media are presented in table.1.TheEIStechnique have been one of the most used methods to report the mechanism of corrosion and corrosion protection of metals and alloys in aggressive media

[42-48]

. The Nyquist plots obtained for the pipeline steel electrodes at

an open-circuit potential after their immersion solutions



237

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi

Table.1.Electrochemical Potentiodynamic Polarization Studies of Stainless steel in the presence of trisodium phosphate SYSTEM Ecorr

Bc

b’c

LPR

Icorr

Ref

SS 18/8

1/5.740

1/5.139

4375896

9.133X10-9

1933

-152

Cde

Z

Phase angle

3.746

78.24

3.946

75.67

106.9 =1826.1 SS+TSP

-109

1/5.991

1/3.793

10544308

4.214X10-9

4244 0

=4244



217

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi Figure.5.Stainless steel in blank

Figure.6.Stainless steel in trisodium Phosphate

5. Conclusion Environmentally acceptable organic corrosion inhibitor was used in the stainless steel perfect the presence of trisodium phosphate inhibits the corrosion process on the stainless steel. The results obtained from present study showed that trisodium phosphate is a good inhibitor and acted as a cathodic inhibitor in petroleum oil water. Surface layer formed on stainless steel 18/8 in trisodium phosphate studied by polarization and electrochemical studies which shows tri sodium phosphate inhibitor under SS 18/8 is a suitable inhibitor can be used for oilwell water systems. 6. Reference [1]J.Sathyabama, S.Rajendran, J.Arockia selvi& J.eya sundari,The open corrosion journal 2(2009)76 [2]V.Kumar, corrosion rev16 (1998) 317. [3]P.Gareces, M.C.Andrade, A.Saez&M.C.Alonso,corrosion science.47(2005)289. [4]M.Moreno,W.morris,M.G.Alvarez and G.S.Duffo,corrosion science 46 (2004).268. [5]X.Zhow,H.Y.Yang,F.H.wang,corrosion science&protection technology 22(4)(2010)(43). [6]P.Ghods,O.B.Isgaor,G.A.Mcrae,G.P.GV,corrosion science 52(5)(2010) 1649.



218

Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi [7]S.Agnesia

Kanimozhi&

s.Rajendran,

International

journal

of

electro

chemical

science,4(2009)353. [8]Emeka E.Oguzie,corrosion science,50(11)(2008)2993. [9]Sastri, V. S.,"Corrosion inhibitors",(1998 ). [10]Mansfeldm, F., Kendig, M. W. and Lorenz, W. J., (1985), “corrosion inhibition in Neutral, AeratedMedia", J. Electronchem Soc,Vol. 132, NO.2 P290-296. [11]WangD,Li Shuyuan,Y,Wang,M,Xiao,H,Chen, Z, "Tsheoretical and Experimental Studies of Structure and Inhibition Efficiency of Imidazoline Derivatives", Corrosion Science, Vol. 41, (1999), P1911-1919. [12]Campbell, S., Jovancicevic, V.,"Corrosion Inhibitor Film Formation Studied by ATR-FTIR", Corrosion/99, (1999) Paper No.484. [13]Videm, K. and Kvarekvaal, J.,Corrosion/96,( 1996). [14]Crolet, J., Thevenot, N. and Nesic, S.,Corrosion/96, (1996 ),paper no.4. [15]Nesic, S., Thevenot, N., Crolet, J. and Drazic, D., Corrosion/96, (1996) paper no.3. [16]Heuer, J.K. and Stubbins, J.F.,corrosion( 1998), 54, P566 . [17]Schmitt, G., Gudde, T., and Strobel-Effertz, E.,"Fracture Mechanical Properties of CO2 Corrosion Product Scales and Their Relation to Localized Corrosion", Corrosion/96, (1996 )9. [18]Kowata,K,and Takahashi,K,"Interaction of Corrosion Inhibitor with Corroded Steel Surface", corrosion/96, (1996) paper.no219. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi [19]Walter, G.W., 1991, Corrosion Science, Vol. 32. No.10 p1041. [20]Tan, Y.J., Bailey, S. and Kinsella, B.,Corrosion Science,(1996) Vol. 38, No.9, pp 1545.

[21]Hackerman N. and Hurd R. M, (1962), proc. Int. congress of metallic corrosion, london, butterworths, P 166. [22]Walter, G. W., 1986,"a review of Impedance plot methods used for corrosion performance ananlysis of painted metals", corrosion science, Vol. 26, No.9,pp 681-703. [23]Mertens, S.F., Cooman, B.C., Temmerman, E.,Corrosion, Vol. 55, NO.2, pp151-156. [24] M. S. Al-Otaibi, A. M. Al-Mayouf,. M. Khan, A. A. Mousa, S. A. Al-Mazroa e H. Z. Alkhathlan,“corrosion inhibitory action of some plant extracts on the corrosion of mild steel in acidic media,” Arabian Journal of Chemistry, pp. 1-7,( 2012). [25] I.B. Obot, N.O. Obi-Egbedi, S.A. Umoren,“antifungal drugs as corrosion inhibitors for aluminium in 0.1 M HCl,” Corrosion Science, vol. 51, issue 8, pp.(2009) 1868-1875. [26] A. Yıldırım, M. Çetin,“synthesis and evaluation of new long alkyl side chain acet‐ amide, isoxazolidine and isoxazoline derivatives as corrosion inhibitors” corrosion science, volume. [27]R. Geethanjali* and S.Subhashini,Investigation of Corrosion Inhibition Efficiency of Some Synthesized Water Soluble Terpolymers on N-80 Steel in HCl, NaCl and Simulated Oil Well Water . [28]E.M. Sherif, S-M. Park, J,Electrochem. Soc, 152 (2005) B205. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Application of Electrochemical Studies in Corrosion Inhibition of Stainless Steel 18/8 in Oil Well Water Using Trisodium Phosphate as Inhibitor M. Abinaya and S.Devi Meenakshi [43]N. Putilova, S.A. Balezin, V.P. Barannik,‘Metallic Corrosion Inhibitors’, (1966), London, Pergamon Press. [44]J.Mater.Environmental science 4(5)(2013) 625-638. [45]Mernari B, Kadi,L,Kertit,S.Bull ,electrochem.,17(3)(2001)115. [46]Schmid,G.M.,Huang,H.J,corrosion science 20(8-9)(1980)104. [47]Obi-Egbedi.N.O.Essien.K.E,Obot,I.B,Ebenso.E.E,International journal of electrochemical science,6(2011)913. [48]A.Suriyaprabha, J. Sathiyabama and S. Rajendran,Cyclic Voltammetric Study of Protective Film Formed By Tri Sodiumcitratess In Simulated Concrete Pore Solution on Mild Steel.




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Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion onio extract, Zn2+ and N-cetyl-N,N,N-Trimethyl Trimethyl Ammonium bromide A. Josephine Vanitha et al.,

Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn2+ and N-cetyl-N,N,N N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha [a], A. Sahaya Raja [b], Susai Rajendran [c] R, Joseph Rathis [d]and S .Santhana Prabha[d] . [a] Department of Chemistry, Sri Meenakshi Govt. Arts College for Women (Autonomous), Madurai, Tamil Nadu, India, E-mail E : [email protected] [b] PG & Research Department of Chemistry, GTN Art College, Dindigul, India, E E-mail : [email protected] [c] Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul women 624 005,Tamil Nadu, India. Email: [email protected] [d]PSNS College of Engineering and Technology, Dindigul, India

Abstract Surface analysis of protective film formed on aluminium immersed in an aqueous solution containing 60 ppm Cl- at pH=11 for one day system in presence of unboiled onion extract (UE), Zn2+ and N-cetyl-N,N,N-Trimethyl Trimethyl Ammonium bromide (CTAB) has been evaluated by weight loss method. The formulation consisting of 10 mL of UE, 2.5 ppm of Zn2+ and 250 ppm of NInter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. 223 Int J Nano Corr Sci and Engg 3(4)(2016) 223-245 Editors: Dr S Rajendran, A Christy Catherine Mary

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Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn2+ and N-cetyl-N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha et al.,

cetyl-N,N,N-Trimethyl Ammonium bromide (CTAB) has 98% inhibition efficiency.

AC

impedance spectra reveal that a protective film is formed on the metal surface. FTIR spectra reveal that the protective film consists of Al3+-UE and Al3+-CTAB complex. The protective film formed on the metal surface are further analysed with the help of atomic force microscopy (AFM). Keywords: Aluminium, Onion, N-cetyl-N,N,N-Trimethyl Ammonium bromide, FTIR, AFM 1. Introduction At the start of Second World War, aluminium -0.05% Copper alloys were used in marine and aircraft [1]. Aluminium – Copper alloys are widely used because of their high strength to weight ratio; but they have relatively low corrosion resistance.

Over the years, there has been a

suspicion that aluminium – cooking vessels are dangerous to health. In early days – before experience was gained – aluminium vessels occasionally came to the market, because these vessels developed pits and it was difficult to clean them. It was thought that these vessels may cause illness through the decayed food remaining in the pits. Acids dissolve aluminium vessels to a considerable extent. Lemon juice contains citric acid. Corrosion behaviour of B26S aluminium in lemon juice containing sweeteners such as glucose, sugar, saccharine and sorbitol was studied by Pandaya and Joshi [2].Aluminium has high resistance to corrosion in many environments due to the presence of protective surface film formed rapidly in air or in neutral aqueous solution [3].

However, in environments containing aggressive anions, primarily

chlorides, the protective film gets locally damaged, and a corrosive attack takes place. One of the methods to prevent this type of corrosion is the action of adsorptive inhibitors whose role is to isolate the metal from the reactions, which cause dissolution of the metal. A great deal of attention is therefore turned to a study of adsorption of organic substances on the electrode surface. Significant contributions have been made by Trabanelli [4] and Trasatti [5]. Despic et al., [6] and Radosevic et al., [7] have investigated the inhibition of corrosion of aluminium. Polarization techniques have been used to examine the action of pyridine derivatives as corrosion inhibitors for high – purity aluminium in 2M NaCl solution. Variation in protection efficiency is Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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evident for different additives when п electron density of the centre of adsorption increases or decreases [8]. Aluminium and its alloys containing metals such as In, Mg, Zn, and Ga have been found to be useful as anodes in alkaline batteries [9, 10]. Corrosion of aluminium in NaOH solution has been prevented by addition of catechol and calcium oxide [11]. Due to environmentprotection awareness, there is a move to make use of environmental friendly natural products as corrosion inhibitors. Rajendran et al., have used an aqueous extract of onion, in controlling corrosion of aluminium in an aqueous solution containing 60 ppm of Cl- at pH 11 and 12 (NaOH).

Influence of N-cetyl-N, N, N – trimethyl ammonium bromide, (CTAB), sodium

sulphite, Zn2+ and immersion period on the inhibiting nature of onion extract has been investigated. The protective film has been analyzed by FTIR spectra [3]. Corrosion behaviour of aluminium in rain water containing garlic extract has studied at pH 11 and 12. The influence of CTAB, sodium sulphite, Zn2+ and duration of immersion has also been investigated [12]. The present work is undertaken, (i)

to evaluate the inhibition efficiency of curcumin, in controlling corrosion of aluminium in an aqueous solution containing 60 ppm of Cl- at pH 11(NaOH) by weight loss method.

(ii)

to study the influence of N-cetyl-N, N, N – trimethyl ammonium bromide (CTAB) on the inhibition efficiency of unboiled onion extract –Zn 2+ system.

(iii)

to study the mechanistic aspects of corrosion inhibition by electrochemical study namely AC impedance spectra

(iv)

to analyze the protective film formed on the metal surface by FTIR spectroscopy and AFM

(v)

to propose suitable mechanism of corrosion inhibition based on the above results.

2. Materials and Methods 2.1 Preparation of unboiled onion extract



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10g of commercially available onion was ground, mixed with water, filtered, then made upto 100 mL in a standard measuring flask by using double distilled water. 2.2 Preparation of specimens Commercial aluminium specimens of dimensions 1.0x4.0x0.2cm. Containing 95% pure aluminium were polished to mirror finish, degreased with trichloroethylene, and used for the weightloss method and for surface examination studies. 2.3 Weight loss method Three aluminium specimens were immersed in 100 ml of the solution containing 60 ppm of Cl- and various concentrations of the inhibitor(curcumin extract) in the absence and presence of Zn2+, at pH 11 (NaOH) for a period of 1 day. The weight of the specimen before and after immersion was determined using Shimadzu balance AY62.

Inhibition efficiency (IE) was

calculated from the relationship IE = (1- W2/W1) x 100, where W1 = corrosion rate in the absence of inhibitor, and W2 = corrosion rate in the presence of the inhibitor. 2.4 Alternating current impedance spectra AC impedance spectra were recorded were recorded in an H and CH electrochemical work station Impedance Analyzer Model CHI 660A provided with iR compensation facility, using a three electrode cell assembly. Aluminium was used as working electrode, platinum as counter electrode and saturated calomel electrode (SCE) as reference electrode. The real part (Z’) and imaginary part (Z”) of the cell impedance were measured in ohms for various frequencies. The charge transfer resistance (Rt) and double layer capacitance (Cdl) values were calculated. 2.5 Surface examination study The aluminium specimens were immersed in various test solution for a period of 1 day. After 1 day, the specimens were taken out and dried. The film formed on the surface of the metal specimens was analysed by surface analysis technique. 2.6 FTIR spectra



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These spectra were recorded with the Perkin – Elmer - 1600 spectrophotometer. The FTIR spectrum of the protective film was recorded by carefully removing the film mixed it with KBr and making the pellet.

2.7 Atomic Force Microscopy characterization (AFM) The aluminium metal specimen immersed in aqueous solution containing 60 ppm Cl- and in the inhibitor solution for a period of one day was removed, rinsed with double distilled water, dried and subjected to the surface examination. The surface morphology measurements of the aluminium surface were carried by atomic force microscopy (AFM) using NT-MDT-Ireland incorporation AFM instrument operating in contact mode in air. 3 RESULTS AND DISCUSSION 3.1 Analysis of result of the weight loss method The inhibition efficiencies (IE) of UE (unboiled onion extract) in controlling corrosion of aluminium immersed in aqueous solution containing 60 ppm Cl- at pH=11, for a period of one day in the presence and in the absence of Zn2+ by weight loss methods are given in Table 1. The corresponding corrosion rates (CR) of aluminium immersed in aqueous solution containing 60 ppm Cl- at pH=11, for a period of one day in the presence and absence of UE and Zn2+ system is given in Table 2.UE alone has some IE and Zn2+ alone also has some IE. When a given concentration of UE is combined with Zn2+ it is found that the inhibition efficiency decreases with increase in the concentration of Zn2+. However the formulation consisting of 10 mL of UE and 2.5 ppm of Zn2+ shows 54 percent of IE. This suggests a synergistic effect between UE and Zn2+. N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) also has some IE, when a given concentration of CTAB increases the inhibition efficiency also increases. However the 250 ppm of CTAB shows 35 percent of inhibition efficiency. The values are shown in Table 3. Corrosion rates (CR) of aluminium immersed in an aqueous solution containing 60 ppm Cl- at pH=11 for one day system and the inhibitor chosen were unboiled onion extract (UE)+Zn2+ in the absence and in the presence of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) as a Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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co-inhibitor has been evaluated and the corrosion rate is given in the Table 4. efficiencies (IE) are also given in this Table. The corrosion rates of the UE-Zn

The inhibition 2+

in presence of

CTAB as co-inhibitor system at various concentrations are shown in Fig.1. Table 1. Inhibition efficiencies (IE %) obtained from UE-Zn2+ systems, when aluminium immersed in an aqueous solution containing 60 ppm Cl- at pH=11. Inhibitor system: UE + Zn2+; UE (mL) 0 2 4 6 8 10

Immersion period: 1 day.

Inhibition efficiency (IE %) Zn2+ (ppm) 0 2.5 5 10 -8 5 4 28 34 20 18 33 38 26 20 40 44 35 25 45 50 41 28 48 54 46 33

Table 2. Corrosion rates (CR) obtained from UE-Zn2+ systems, when aluminium immersed in an aqueous solution containing 60 ppm Cl- at pH=11. Inhibitor system: UE + Zn2+ UE (mL) 0 2 4 6 8 10

Immersion period: 1 day

Corrosion rates (mm/y) Zn2+ (ppm) 0 2.5 5 10 0.30608 0.28157 0.29078 0.29384 0.22038 0.20201 0.24487 0.25099 0.20507 0.18977 0.22650 0.24487 0.18365 0.17140 0.19895 0.22956 0.16834 0.15344 0.18059 0.22038 0.15916 0.14080 0.16528 0.20507

Table 3 : Corrosion rates (CR) of aluminium immersed in an aqueous solution containing 60 ppm Cl- of co-inhibitor system at various concentrations and the obtained inhibition efficiencies (IE) by weight loss method Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Immersion period : 1 day

pH = 11 Cl(ppm) 60 60 60 60 60

CTAB (ppm) 50 100 150 200 250

CR (mm/y) 0.25405 0.24487 0.22650 0.21732 0.19895

IE % 17 20 26 29 35

Table 4 : Influence of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) on the inhibition efficiency of UE-Zn2+ system Inhibitor system

: 10 mL of UE + 2.5 ppm of Zn2+ + 250 ppm of CTAB

Immersion period pH = 11

: 1 day

Clppm 60 60 60 60 60 60 60 60 60

UE mL 0 0 10 10 10 10 10 10 10

Zn2+ ppm 0 2.5 0 2.5 2.5 2.5 2.5 2.5 2.5

CTAB ppm 0 0 0 0 50 100 150 200 250

CR mmpy 0.30608 0.28157 0.16833 0.1407 0.12242 0.10406 0.07957 0.03366 0.00612

IE % -8 48 54 60 66 74 89 98

It is observed from Table 4 that as the UE 10 mL and Zn2+ 2.5 ppm remains constant and when CTAB increases the IE also increases. The highest IE 98% was obtained when UE was 10 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn2+ and N-cetyl-N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha et al., 2+

mL, Zn

2.5 ppm and the CTAB 250 ppm. This is due to the fact that the protective film

(probably aluminium-UE and aluminium-CTAB complex) formed on the metal surface. That is the system passes from active region to passive region [1-3].This suggests a synergistic effect existing between the ternary inhibitor formulation, UE (unboiled onion extract), Zn2+ ion and CTAB (N-cetyl-N,N,N-trimethyl ammonium bromide).In presence of UE and CTAB, Al3+-UE complex and Al3+-CTAB complex are formed on the metal surface.

Thus the anodic and

cathodic reaction is controlled.

0.14

120

0.12

100

0.1 0.08 60

IE %

CR, mm/y

80

0.06 40

0.04 20

0.02 0

0

50

100

150

200

250

EDTA, ppm CR mm/y

IE %

Fig.1 : Corrosion rates (CR) and inhibition efficiency (IE) of aluminium immersed in various test solutions



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3.2 Synergism parameters (SI) Synergism parameters (SI) have been used to know the synergistic effect existing between two inhibitors [4-9]. Synergism parameter (SI) can be calculated using the following relationship. 1- 1+2

Synergism parameter (SI)

= 1- '1+2

Where 1+2 =

( 1 + 2) – ( 1 2), = Surface coverage by UE-Zn2+ 1 2

' 1+2

where

= Surface coverage by CTAB

= Surface coverage by both unboiled onion-Zn2+ and CTAB IE % surface coverage = 100

The synergism parameters of UE-Zn2+ in the presence of CTAB as co-inhibitor system are given in Table 5,

for different concentrations of inhibitors, SI approaches 1 when no

interaction between the inhibitor compounds exists. When SI > 1, it points to synergistic effects. In the case of SI < 1, it is an indication that the synergistic effect is not significant [4]. From Table 5, it is observed that value of synergism parameters (SI) calculated from surface coverage were found to be one and above. This indicates that the synergistic effect exists between UEZn2+-CTAB [5-8]. Table 5 : Inhibition efficiencies and synergism parameters for various concentrations of UEZn2+-CTAB system, when aluminium is immersed in aqueous solution containing 60 ppm of Cl-.



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Immersion period : 1 day

pH = 11

UE 10 Combined Inhibition Surface mL Surface Combined Synergism CTAB surface efficiency Coverage + Coverage IE % Parameters ppm coverage IE (%) θ1 Zn2+ θ2 I'1+2 SI θ'1+2 2.5 ppm 50 17 0.17 54 0.54 60 0.60 0.795 100 20 0.20 54 0.54 66 0.66 1.05882 150 26 0.26 54 0.54 74 0.74 1.30924 200 29 0.29 54 0.54 89 0.89 2.96909 250 35 0.35 54 0.54 98 0.98 5.98 3.3 'F'-test F-test is used to confirm if the synergism effect existing between UE-Zn2+-CTAB is statistically significant or not [9]. The results are given in Table 6. It is observed that the calculated F-value of UE-Zn2+-CTAB is 44.69, which is greater than the critical F-value (5.32) for 1,8 degrees of freedom at 0.05 level of significance. So it is concluded that the synergistic effect existing between unboiled onion-Zn2+ and CTAB (N-cetyl-N,N,N-trimethyl ammonium bromide) is statistically significant. This is in agreement with conclusion derived from calculation synergism parameter. Table 6 : Distribution of F-value between the inhibition efficiencies of various concentrations of unboiled onion-Zn2+ and the inhibition efficiencies of CTAB

Source of variance Between the sample Within the sample

Sum Degrees of of square freedom 1352 1 242

8

Mean square

Fvalue

level of significance

44.69

p > 0.05

1352 30.25



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3.4 Analysis of AC impedance spectra AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface [16-28]. If a protective film is formed on the metal surface, charge transfer resistance (Rct) increases, double layer capacitance value (Cdl) decreases and the impedance log(z/ohm) value increases.

The AC impedance spectra of

aluminium metal immersed in an aqueous solution containing 60 ppm of Cl- in the absence and in presence of inhibitors (unboiled onion extract, Zn2+ ion and N-cetyl-N,N,N-trimethyl ammonium bromide) are shown in Fig.2(a,b,c) (Nyquist plots) and Fig.3(a,b,c) (Bode plots). The AC impedance parameters namely charge transfer resistance (Rct) and double layer capacitance (Cdl) derived from Nyquist plots are given in Table 7. The impedance log(z/ohm) values derived from Bode plots are given in Table 7. It is observed that when the aluminium is immersed in an aqueous solution containing Cl60 ppm, the charge transfer resistance (Rct) is 6358.6 ohm cm2. When the inhibitor UE 10 mLZn2+ 2.5 ppm is added, the charge transfer resistance (Rct) is increased from 6358.6 ohm cm2 to 7645.7 ohm cm2. Further co-inhibitor CTAB 250 ppm is added, the charge transfer resistance (Rct) is increased from 7645.7 ohm cm2 to 9445.7 ohm cm2. The UE 10 mL + Zn2+ 2.5 ppm is added to the solution containing 60 ppm Cl- the Cdl value decreases from 8.0206 x 10-10 F/cm2 to 6.6704 x 10-10 F/cm2. When the co-inhibitor CTAB 250 ppm is added to the above system, the Cdl value further decreases from 6.6704 x 10-10 F/cm2 to 5.3992 x 10-10 F/cm2. The impedance value [log(z/ohm)] increases from 3.78 to 3.96 when UE 10 mL + Zn2+ 2.5 ppm is added to Cl60 ppm. When co-inhibitor CTAB 250 ppm is added to the above system the impedance value [log(z/ohm)] slightly decreases from 3.96 to 3.92. These results lead to the conclusion that a protective film is formed on the metal surface.



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Table 7 : Corrosion parameters of aluminium immersed in an aqueous solution containing 60 ppm of Cl- in the presence of inhibitor system obtained from AC impedance spectra

System Cl- 60 ppm Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm

Nyquist plot Rt Cdl ohm cm2 F/cm2 6358.6 8.0206 x 10-10 7645.7 6.6704 x 10-10

Bode plot Impedance value log(z/ohm) 3.78 3.96

5.3992 x 10-10

9445.7

3.92

b c a

Fig.2 : AC impedance spectra of aluminium immersed in various test solutions (Nyquist plot) (a) Cl- 60 ppm (blank) (b) Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm (c) Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Fig.3(a) : A Bode plots of aluminium immersed in an aqueous solution containing Cl- 60 ppm (blank)



235


Fig.3(b) : A Bode plots of aluminium immersed in an aqueous solution containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm



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Fig.3(c) : A Bode plots of aluminium immersed in an aqueous solution containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm 3.5 Analysis of FTIR spectra FTIR spectra have been used to analyses the protective film formed on the metal surface [12,22,27-33]. The structure of pure onion extract is shown in Fig.4(a). The structure of pure CTAB is shown in Fig.4(b). The FTIR spectrum (KBr) of pure onion extract is shown in Fig.5(a). The OH stretching frequency appears at 3440 cm-1.

The C=O group stretching

-1

frequency appears at 1645 cm . The C=O group stretching, in configuration with double bond appears at 1645 cm-1. Thus, unboiled onion was characterized by IR spectroscopy [23].



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The FTIR spectrum (KBr) of pure sodium molybdate is shown in Fig.5(b). The C-N stretching frequency of CTAB appears at 1145 cm-1. FTIR spectrum of film formed on the metal surface after immersion in an aqueous solution containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm. It is found that the -OH has shifted from 3440 cm-1 to 3482 cm1

. The C=O stretching frequency has decreased from 1645 cm-1 to 1600 cm-1. The C-N

stretching frequency has shifted from 1145 cm-1 to 1050 cm-1. It was inferred that unboiled onion has coordinated with Al3+

through the phenolic oxygen and carbonyl oxygen, 3+

resulting in the formation of the Al - unboiled onion complex on the anodic sites of the metal surface. The peak at 820 cm-1 is due to metal-O band. The peak at 3482 cm-1 is due to –OH stretching. Hence it is confirmed that Al(OH)3 and Zn(OH)2 is formed on the anodic sites of the metal surface is shown in Fig.5(c) [24]. Thus, the FTIR spectral study leads to the conclusion that the protective film consists of the Al3+ - UE and Al3+-CTAB complex and metalhydroxide (Al(OH)3 and Zn(OH)2) [25].

Fig.4(a). Structure of onion extract



238


Fig.4(b). Structure of CTAB

Fig.5(a) : FTIR spectrum of pure unboiled onion



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Fig.5(b) : FTIR spectrum of pure CTAB

Fig.5 : FTIR spectrum of (d) film formed on the metal surface after immersion in an aqueous solution containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm 3.6 Atomic Force Microscopy Characterization Atomic force microscopy is a powerful technique for gathering roughness statistics from a variety of surfaces [47]. AFM is becoming an accepted method of roughness investigation [4854].All atomic force microscopy images were obtained in a help of a NT-MDT-Ireland incorporation AFM instrument operating in contact mode in air. The scan size of all the AFM Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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images are 5 µm x 5 µm areas at a scan rate of 0.5112 µm/second, direction of scanning is horizontal, line by line scanning rate is 256. The varying scan rate depends upon the frequency and scanning area of the sample. AFM study was taken only for the best system UE-Zn2+-CTAB which has 98% IE. The two dimensional (2D), three dimensional (3D) of the AFM morphologies, AFM cross-sectional profile and histogram images of surface for aluminium metal immersed in 60 ppm Cl-, aluminium metal immersed in UE-Zn2+ and aluminium metal immersed in 10 mL of UE, 2.5 ppm of Zn2+ and 250 ppm of CTAB are shown in Fig.6 (a,b,c), (d,e,f), (g,h,i), (j,k,l) respectively. Table 8 is the summary of the average roughness (Ra), RMS roughness (Rq), maximum peak-to-valley height (P-V) value, surface skewness (ssk), coefficient of kurtosis (Ska) and

Entropy for aluminium metal surface immersed in different environments.The AFM images of aluminium metal immersed in 60 ppm of Cl- in the absence and presence of UE 10 mL, 2.5 ppm of Zn2+ and 250 ppm of CTAB are shown in Fig.6 (a,b,c) (d,e,f) (g,h,i). The various parameters such as RMS, Rq, maximum peak to peak, surface skewness, co-efficient of Kurtosis and entropy derived from these Fig.6(a,b,c) (d,e,f) (g,h,i) (j,k,l) are given in the Table 8. The value of RRMS, Ra, Peak to valley height, skewness, co-efficient of kurtosis and entropy for the polished aluminium metal surface are 0.095 µm, 0.068 µm, 0.437 µm, -0.402 µm, 0.323 µm and 3.824 respectively, which shows a more homogeneous surface, with some places in which the height is lower than the average depth [47]. Fig.6(a) displays the uncorroded metal surface. The slight roughness observed on the aluminium metal surface is due to atmospheric corrosion. The rms roughness, average roughness, P-V height, surface skewness (ssk), coefficient of kurtosis (ska) and entropy values for the aluminium metal immersed in aqueous solution containing 60 ppm Cl- are 0.053 µm, 0.041 µm, 0.154 µm, -0.433 µm, 0.209 µm and 3.420 µm respectively. These data suggest that aluminium metal surface immersed in 60 ppm of Cl- has a greater surface roughness than the polished metal surface.

This shows that the



241


unprotected aluminium metal surface is rougher and is due to the corrosion of the aluminium metal in 60 ppm of Cl-. Fig.6(b) displays the corroded metal surface with few pits. The presence of aluminium metal immersed in aqueous solution containing 60 ppm Cl- + UE 10 mL+Zn2+ 2.5 ppm + CTAB 250 ppm reduces all factors. Where entropy is decreased when compared with aluminium metal immersed in aqueous solution containing 60 ppm Clfrom 3.420 µm to 3.210 µm These parameters confirm that the surface appears smoother. The smoothness of the surface is due to the formation of a compact protective film of Al3+-UE and Al3+-CTAB complex on the metal surface inhibiting the corrosion of aluminium metal. Also, the above parameters are observed somewhat greater than the AFM data of polished aluminium metal surface, which confirms the formation of the film on the metal surface, which is protective in nature.

3.7 Histogram The histogram is an effective graphical technique for showing both the skewness and kurtosis of data set [54]. The histogram shown in Figs.6(j,k,l) exhibits the above analysis with suitable graphical representation. Fig.6(j) of histogram image of polished aluminium metal shows very least symmetry and slight roughness. When immersed in 60 ppm of Cl- (Fig.6(k)) it shows slight symmetry and high roughness. When immersed in 60 ppm of Cl- and UE-Zn2+CTAB (Fig.6(l)) shows high symmetry and less roughness and high smoothness. So, corrosion resistant is present slightly. Table 8 : AFM data for aluminium metal and CTAB surfaces immersed in inhibited and uninhibited environments

Samples

Aluminium

Average RMS (Rq) (Ra) Roughness Roughness (µm) (µm) 0.195

0.146

Maximum peak-toSurface Coefficient Entropy peak skewness of kurtosis (Rku) height (ssk) (ska) (µm) 1.071 -0.602 0.823 3.634



242

Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn2+ and N-cetyl-N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha et al., -

immersed in Cl 60 ppm (control) Alulminium immersed in Cl60 ppm + UE 250 ppm + Zn2+ 2.5 ppm Aluminium immersed in Cl60 ppm + UE 250 ppm + Zn2+ 2.5 ppm + CTAB 250 ppm

0.053

0.041

0.154

-0.433

0.209

3.420

0.068

0.053

0.146

-0.138

253.248

3.210

Fig.6 (a) (b) (c) 2D AFM images of the surface of (d) (e) (f) 3D AFM images of the surface of

(a)(d)(g)(j) Aluminium metal immersed in an aqueous solution containing Cl- 60 ppm (control)



243

Surface analysis of protective film formed on aluminium immersed in an aqueous solution at pH 11 in presence of unboiled onion extract, Zn2+ and N-cetyl-N,N,N-Trimethyl Ammonium bromide A. Josephine Vanitha et al., (g) (h) (i) The cross sectional profile which are (b)(e)(h)(k) Aluminium metal immersed in an aqueous solution corresponding to as shown broken lines containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm in AFM images of the surface of (c)(f)(i)(l) Aluminium metal immersed in an aqueous solution (j) (k) (l) Histogram images of the surface of containing Cl- 60 ppm + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm

4 CONCLUSION 1) Weight loss study shows that the formulation consist of 60 ppm of Cl- at pH 11 + UE 10 mL + Zn2+ 2.5 ppm + CTAB 250 ppm has 98% IE. 2) AC impedance spectra reveal that the protective film formed on the surface. 3) FTIR spectra reveals that the protective film consists of Al3+-UE and Al3+-CTAB complex and Zn(OH)2 4) The AFM images confirm the formation of protective layer on the metal surface. 5 ACKNOWLEDGEMENT The authors are thankful to their respective managements and to university Grants commission, India for their help and encouragement. 6 REFERENCE 1. U.R.Evans, “The Corrosion and Oxidation of Metals. Scientific Principles and Practical”, Edward Arnold Pub. Ltd., London (1960) – P.10 2. J.M. Pandya and S.D. Joshi, Proc. National Symposium on Electrochemistry in Aerospace Systems, ISRO Satellite Centre Centre, Bangalore, India. Nov.20 & 21, 1998, P.97. 3. Susai Rajendran, S.Muthulakhsmi, R.Rajeswari and A.Vijitha, J.Electrochem Soc, India. 54(2) (2005) 50. 4. G.Trabanelli, “Corrosion Mechanism”, F.Mansfeld Dekker Inc., New York (1987) p.119. 5. S.Trasatti, Electrochem. Acta., 37, (1998)2137. 6. A.Despic, J.Radosevic and M.Kilskic, Proc. 7th Europ. Symp. Corrosion Inhibitors, Univ. Ferrara, Ferrara, Italy, 2 (1990) 1119. 7. J.Radosevic, M. Kiliskic and A.Despic, J.Appl. Electrochem., 22 (1992) 649.



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8. J.Radosevic, M. Kiliskic, L.J. Alijnovic and S.Vuko, Pro. 8th Europ. Symp. Corrosion Inhibitors, 2 (1995) 817. 9. S.Zaromb, “Power Systems for Electric Vehicles”, A symposium sponsored by U.S. Department of HEW, New York, (April 1967) 225. 10. A.R. Despic Ind. J.Tech., 24 (1986) 465. 11. T.Jeyaraj, C.Raja and V.Violet Dhayabaram, Transaction of the SAEST, 37 (1) (2002) 25. 12. S.Lakshmi Priya, A.Chitra, S.Rajendran and K.Anuradha, Surface Engineering, 21(3) (2005) 229. 13. J.H. Morgan, "Cathodic Protection", The Maxmillion Company, New York (1960) 14. O.L.Riggs and C.E.Locke, "Anodic Protection", Plenum Press, New York (1981). 15. S.S.Elegamy and W.A. Badaway, J.Appl. Electro.Chem., 34 (2004) 1153. 16. G. K. Gomma, Mater.Chem.Phys.55 (1998) 241. 17. K. Aramaki and N. Hackermann, J. Electrochem. Soc. 116 (1969) 568. 18. M. A. Quraishi, J. Rawat and M. Ajmal, Corrosion. 55 (1999) 919 19. S. Agnesia Kanimozhi and S. Rajendran, Int. Journal of Electrochemical Society, 4 (2009) 353. 20. D. Gopi, S. Manimozhi, K. M. Govindaraju, P. Manisankar and S.Rajeswari, J.Appl.Electrochem, 37(2007) 439-449.




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SYNTHESIS AND STUDIES ON ANIONIC TRANSITION METAL COMPLEXES WITH TETRAAZA PROTONATED 2,3,8,92,3,8,9 TETRAHYDROXY-1,4,7,10-TERAAZACYCLODODECANE TERAAZACYCLODODECANE-1,3,7,9-TETRAENE AS CATION

SYNTHESIS AND STUDIES ON ANIONIC TRANSITION METAL COMPLEXES WITH TETRAAZA PROTONATED 2,3,8,92,3,8,9 TETRAHYDROXY-1,4,7,10 1,4,7,10-TERAAZACYCLODODECANE TERAAZACYCLODODECANE-1,3,7,9TETRAENE AS CATION ANGUSAMY SELVAN Department of Chemistry, Government Arts College for Women, Nilakottai – 624 208. 1. Introduction Research on coordination chemistry of macrocycles gains impetus in recent years due to their multifaceted applications as receptors, sensors, luminescent probes, contrast agents for NMR; the vitality arises from their crucial roles in bio-systems. bio systems. Many synthetic tetraaza macrocycles have been extensively investigated to bio-mimic mimic the naturally occurring macrocycles such as porphyrin,, corrin rings. The biological role of the polyazamacrocycles is due to their ability to interact with both metal cations and anionic species. Indeed, the designs of synthetic anion complexing reagents have focused on cationic protonated polyazacycles such as polyammonium, polyguanidinium, quaternary ammonium macrocycles and so on. These cycles by virtue of having high positive charge density and potential hydrogen bonding sites site promote complex formation with biologically relevant anionic substrates.

Molecular architecture of

protonated polyaza macrocycles can be modulated in order to selectively bind different guests, from simple inorganic anions to species of biological relevance, relevance, such as nucleotide phosphates, ATP, DNA, and RNA. Protonated polyaza macrocycles are found in all organisms, largely bound in cells to RNA and DNA. They have long been associated with cell growth and cancer, and continued to be molecules that hold fascination fascination for biologists, chemists, molecular biologists and clinical researchers. Various polyamines dendrimers have been studied as gene delivery Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. (4)(2016) 247 247-253 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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SYNTHESIS AND STUDIES ON ANIONIC TRANSITION METAL COMPLEXES WITH TETRAAZA PROTONATED 2,3,8,9TETRAHYDROXY-1,4,7,10-TERAAZACYCLODODECANE-1,3,7,9-TETRAENE AS CATION

vehicles. Further, polyammonium macrocycles are also used as enzyme mimics. In view of the biological relevance and interesting applications, in the present study transition metal complexes containing

tetraaza protonated 2,3,8,9-tetrahydroxy-1,4,7,10-teraazacyclododecane-1,3,7,9-

tetraene as cation have been synthesized and characterized. 2. EXPERIMENTAL SECTION: PREPARATION OF COMPLEXES: 2.1.1 Preparation of the precursor diethyl 2,2'-(ethane-1,2-diylbis(azanediyl))bis (2oxoacetate) [P] Diethyl oxalate (10mL, 74mmol) was dissolved in minimum amount of ethanol in a beaker. When ethylenediamine (1 mL, 15mmol) was added drop wise to the diethyl oxalate solution the precursor [P, Fig.1] (white precipitate) was formed. The solution was stirred for about half an hour to ensure the completion of the reaction. Then the formed precursor was filtered, washed with dichloromethane and then subsequently dried in vacuum over anhydrous CaCl2. 2.1.2 Preparation of Cyclic product 1,4,7,10-tetraazacyclododecane-2,3,8,9 –tetraone [Pcy]. Ethylenediamine (0.17mL, 2.54mmol) was added to the hot ethanolic solution of the precursor [P] (0.658g, 2.52mmol). The solution was stirred for 45 minutes to get a cyclic product [Pcy, Fig.1] as precipitate that was subsequently filtered and dried. 2.2 Template synthesis of metal complexes: Copper(II) chloride dihydrate (247mg, 1.45mmol) dissolved in minimum amount of ethanol was added to the dispersed precursor [P] (376mg, 1.45mmol) in hot ethanol. To this mixture, ethylenediamine (0.1mL, 1.45mmol) was added followed by hydrochloric acid (2.4ml, 10N) and stirred for one hour. Then the solution was concentrated nearly to its one tenth of its volume on a water bath. The formed yellow colour complex [Fig.2] was filtered and dried in vacuum over anhydrous CaCl2. Similarly [Mac.] [MCl6] (M = Co2+, Mn2+, Ni2+ and Zn2+and Mac. = macrocycle) were prepared using corresponding metal salts.



247


Preparation of Precursor

NH2

EtO

O

EtO

O

NH

HN

O

Ethanol

O

+ NH2

O

EtO

OEt

Stoichiometric excess taken

O

Precursor

Preparation of Cyclic Product

HN

O

NH

H 2N

O

NH

O

HN O

+ O

EtO

OEt

O

O

H 2N

NH

O

HN

Precursor

Fig.1

Cyclic product

O

NH

4+

O

HO

OC2 H 5

H2 N

+ MCl2 + NH

O

OC 2H 5

NH +

OH

+HN

+ HCl (aq)

H 2N

RT Ethanol

O

4MCl 6 NH +

HO

+HN

OH

(Mac.) [MCl 6]

Fig.2

3. RESULTS AND DISCUSSION: Table 1. Analytical Data of Complexes Complexes

Elemental analysis data of the complexes Obsd. (Calcd.) (%)

{(Mac.)[CuCl6] } {(Mac.)[MnCl6]} {(Mac.)[CoCl6]} {(Mac.)[NiCl6]}

Metal 12.48 (12.36) 10.98 (10.52) 11.68 (11.45) 11.65 (11.48)

Chloride 41.88 (41.36) 42.60 (42.28) 42.27 (42.12) 42.28 (42.10)

C 18.87 (18.43) 19.20 (19.08) 19.05 (18.98) 19.05 (19.00)

H 3.14 (3.06) 3.20 (3.12) 3.17 (3.08) 3.17 (3.02)

N 11.01(10.98) 11.20(11.03) 11.11(11.05) 11.11(11.02)



248


The complexes were prepared as described in the experimental section. Analytical results of these complexes (Table 1) substantiate the formula [Mac.] [MCl6 ] proposed for the complexes. The molar conductance value of copper indicate the ionic nature of the complex. 3.1 IR spectra of Precursor [P] and Cyclic Product [Pcy] Characteristic infrared spectral bands nicely identify the appended functional groups on the precursor (Fig.3). In the infrared spectrum of precursor, band at 1737cm-1 corresponding to ester carbonyl group. The appearance of the bands at 1658 cm-1 due to amide I (C=O stretching)] and at 1548 cm-1, assignable to the amide II (NH deformation) confirm the presence of amide group.

Fig.3 Further to ascertain the mode of coordination of amide in complexes a cyclic polyamide [Pcy] was prepared from precursor [P] and Ethylenediamine in the absence of metal. Most significantly, the disappearance of band at 1737 cm-1 in the IR spectrum of the cyclic product indicates that during the preparation from the precursor and amine, cyclization occurs by further condensation of the ester groups in precursor with amine. IR spectrum of the amide [Pcy] (Fig.3) shows amide I and amide II bands at 1649 cm-1 (data no.7) and 1531 cm-1 (data no.8) respectively.



249


3.2 IR spectrum of Copper complex

Fig.4 In the IR spectrum of the copper complex (Fig.4), the absence of the expected strong peak for >C=O stretching of protonated amide around 1737 cm-1 implies that the macrocyclic cation exists in protonated iminol form. The peak appearing at 1612 cm-1 is corresponding to >C=N stretching, while a series of bands observed at 2243, 2384, 2492,2557,2638 cm-1 in the region 2700 – 2250 cm-1 are assignable to the NH stretching of >C=N+HR groups. The peak appearing at 1950 cm-1 could be assigned to the NH deformation of >C=N+HR groups. These observations together with the appearance of a new peak at 3124 cm-1 due to OH stretching confirm the complex exists predominantly in the iminol form. The OH deformation peak appearing at 1438 cm-1 in the complex also augments that macrocycle is in iminol form. Table 2. IR spectral data of the complexes Electronic Spectral Data

Vibrational frequency (cm-1) Complex NH

C=N

N+H

OH

λ max (cm-1)

Ε (L mol-1



250


{(Mac.) [CuCl6]}

2638

1612

1950

3124

{(Mac.) [MnCl6]}

2632

1658

2004

3246

{(Mac.)[Co Cl6]}

2636

1581

1926

3410

{(Mac.)[Ni Cl6]}

2632

1658

2004

3182

cm-1) 190 & 196 66 & 215 -

646 & 714 538 & 641 -

3.3 Electronic spectra complexes Copper (II) complex The electronic spectrum of copper (II) complex (Fig.5) shows bands at 15480 cm-1and 14001 cm-1. The earlier studies in the literature on electronic spectrum of Cu(II) complexes indicate that the band at 15480 cm-1 in this complex may be arising due to the transition 2

B1g2Eg (3 ) and 14001 cm-1 band is attributable to the transition 2B1g2 A1gof a tetragonally

distorted octahedral Cu(II) complex. 0.22

641 nm

0.20 0.20

0.18

714 nm 0.16

646 nm

0.18

Absorbance

0.14

Absorbance

0.16

0.14

0.12

538 nm

0.10 0.08 0.06

0.12

0.04 0.10

0.02 0.00

0.08 600

625

650

675

700

725

750

450

775

500

550

600

650

700

750

800

wavelength nm

wavelength (nm)

Fig.5 3.4 Cobalt (II) complex The electronic spectrum of cobalt (II) complex (Fig.5) shows bands at 18587 cm-1and 15601 cm-1. The earlier studies in the literature on electronic spectrum of Co(II) complexes indicate that the band at 18587 cm-1 in this complex may be arising due to the transition 2

B1g2Eg (3 ) and 15601 cm-1 band is attributable to the transition 2B1g2 A1gof a tetragonally

distorted octahedral Co(II) complex. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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3.5 CYCLIC VOLTAMMOGRAMS Copper complex The cyclic voltammogram of {[Mac.] [CuCl6]} complex (Fig. 6) exhibits a cathodic peak (Epc) at -908 mV and an anodic peak (Epa) at - 12mV attributable to the one electron redox couple Cu(II)/Cu(I). The difference between cathodic and anodic peak potentials for Cu(II) complex (Ep) is 896 mV. The Cu(II) complex has a quasi-reversible character as the separation in peak potentials is higher than 59 mV and the peak currents rise with increasing scan rate.

-6

I (A)

I (A)

5.0x10

0.0

4.0x10

-6

3.0x10

-6

2.0x10

-6

1.0x10

-6

0.0

-5.0x10

-6

1000

500

0

E (mV)

-500

-1.0x10

-6

-2.0x10

-6

-1000

500

0

-500

-1000

Fig.6 Table 3. Data of cyclic voltammetric measurement of {(mac.) [mcl6]} complexes E (mV)

Complex {(mac.)[cucl6]} {(mac.) [nicl6]} {(mac.) [cocl6]} {(mac.) [mncl6]}

Epc

Epa

∆ep

(mv)

(mv)

(mv)

-908 -669 -752 -472

-12 -542 -216 -94

896 97 536 378

4. Conclusion {(Mac.)[MCl6]}, the hexachlorometallate(II) anionic complexes tetraaza protonated2,3,8,9-tetrahyroxy-1,4,7,10-tetraazacyclododecone-1,3,7,9-tetrane as cation M = Cu(II), Co(II), Ni(II) and Mn(II) have been synthesized. These were studied by elemental analyses, and IR, UV and CV spectral studies. By electronic spectral studies, the hexachlorometallate(II) anionic complexes have been found to be octahedral. The redox behaviour of the metal in these systems Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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was examined electrochemically by means of CV and found to be quasi reversible.From the above studies the structure was concluded as follows 4+ HO

NH +

OH

+

HN

4MCl 6 NH +

HO

+

HN

OH




253

Corrosion Resistance Of Super Elastic Nickel - Titanium Alloy In Artificial Saliva In Presence Of Almox 250mg Tablet G.Muthukumar et al.,

Corrosion Resistance Of Super Elastic Nickel - Titanium Alloy In Artificial Saliva In Presence Of Almox 250mg Tablet a

a

S.Rajendran*, bA.Krishnaveni*, and cG.Muthukumar

Department of Chemistry, St.Antony’s College of Arts and Sciences For Women, Women Dindigul. b Department of Chemistry, Yadava College, Madurai. c PG& Research Department of Chemistry, Chemistry, The Madura College, Madurai. Email: [email protected] Abstract Corrosion resistance of Super Elastic Nickel Nickel-Titanium alloy oy in artificial saliva, in the

absence and presence of a tablet namely, Almox 250mg has been evaluated by AC Impedance Spectra. It is observed that when 50 ppm of Almox is added to artificial saliva, charge transfer resistance of Super Elastic Nickel-Titanium Nickel nium increases. Similar observation is made in presence of 200 ppm of Almox also. Hence it is concluded that people having orthodontic wires made of Super Elastic Nickel-Titanium, Titanium, can take the Tablet Almox 250mg without any hesitation, because in its presence nce corrosion resistance of Super Elastic Nickel Nickel-Titanium Titanium increases. Keywords: corrosion resistance of metals, Super Elastic Nickel-Titanium Nickel Titanium alloy, synthetic saliva, orthodontic wires.



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1. Introduction In dentistry, metallic materials are used as implants in reconstructive oral surgery to replace a single teeth or an array of teeth, or in the fabrication of dental prosthesis such as metal plates for complete and partial dentures, crowns, and bridges, essentially in patients requiring hypoallergenic materials. Due to its mechanical properties, good resistance to corrosion in biological fluids and very low toxicity, titanium was the most commonly selected material for dental implants and prosthesis. Corrosion of metallic implants was of vital importance, because it can adversely affect the biocompatibility and mechanical integrity of implants. Many metals and alloys have been used in dentistry. Their corrosion behavior in artificial saliva has been investigated. Various metals and alloys have been used as biomaterials whose corrosion resistance has been investigated in artificial body fluids; various metals and alloys such as Ni-Al-Fe intermetallic alloys,[1] titanium alloy,[2] NiTi alloy,[3]CoCrMo alloys,[4, 5] magnesium alloy,[6,7] Cr-Ni stainless steel, Cr-Ni-Mo stainless steel,[8] 316L stainless steel.[9,10]The corrosion resistance of the commercial metallic orthodontic wires in a simulated intra-oral environment has been evaluated by Ziebowicz et al.[11] The results of corrosion resistance tests of the CrNi, NiTi, and CuNiTi wires showed comparable data of parameters obtained in artificial saliva . The corrosion behavior of various metals and alloys in artificial saliva has been investigated. Rajendran et al ., have studied the corrosion resistance of artificial saliva in presence spirulina powder.[12] Corrosion behavior of metals in artificial saliva in presence of D-glucose has been investigated.[13] Koike, et al studied corrosion resistance of Titanium alloy in presence of Artificial Saliva at 37°C using the method of potentiostatic polarization. They have found that all the mechanical properties and corrosion characters were tested [14]. Anwar et al investigated corrosion behavior of Ti and Ti 6Al4V in presence of artificial saliva using electrochemical methods. They found that as fluoride concentration increases, corrosion resistance is decreased.[15] Rajendran et al have studied the corrosion resistance of SS Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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316 L in Artificial Saliva in presence of electral.[16] Ni-Ti alloys have been used by Rondelli and Vincentini[17]. Dentists recommend the use of orthodontic wires to regulate the arrangement of teeth. After the regulation, people having these orthodontic wires, regulating the arrangement of teeth, have to take orally many tablets. These tablets may corrode the wires in the oral environment, especially saliva. Hence there is a need to investigate the influence of various tablets on the corrosion resistance of orthodontic wires made of many metals and alloys. Can people implanted with orthodontic wires made of Super Elastic Nickel-Titanium alloy take Almox 250mg Tablets orally? To give an answer this question, the following investigation was undertaken. Corrosion resistance of Super Elastic Nickel-Titanium alloy in artificial saliva (AS) in the absence and presence of Almox 250mg has been investigated by AC Impedance Spectra. 2.EXPERIMENAL 2.1 Composition of Super Elastic Nickel-Titanium Alloy Nickel – 55.5% and Balance Titanium. Wire of 1mm diameter was used in the present study. [18]

2.2 Chemistry of Almox: Empirical formula: C16H19N3O5S. 3H2O Molecular mass: 419.46 g/mol. White to half white crystalline powder. 2.3 Artificial Saliva The composition of artificial saliva[19] is given as: KCl - 0.4 g/L, NaCl – 0.4 g /L, CaCl2.2H2O - 0.906 g/L, NaH2PO4.2H2O 0.690 g/L, Na2S.9H2O – 0.005 g/L, urea–1 g/L. [19]



256


2.4 MEDICAL USES Amoxicillin is used in the treatment of number of infections including: [20] Pneunomia Skin infections Urinary tract infections

2.5 AC impedance spectra AC impedance spectral studies were carried out in a CHI – Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The working electrode was Super Elastic Nickel-Titanium alloy. A saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. The real part (Z’) and imaginary part (Z”) of the cell impedance were measured in ohms at various frequencies. Values of the charge transfer resistance (Rt) and the double layer capacitance (Cdl) were calculated. 3. Results and Discussion 3.1 Analysis of AC impedance Spectra AC impedance Spectra have been used to detect the formation of film on the metal surface [21-30]. If a protective film is formed, the charge transfer resistance (Rt) increases and double layer capacitance (Cdl) value decreases. The impedance value increases.The AC impedance spectra of Super-elastic Ni-Ti immersed in various test solutions are given in (Fig 1 to 6). The Nyquist plots are given in 1 to 6 The Bode plots shown in (Fig 7 to 13) The corrosion parameters derived from AC impedance spectra are given in Table 1.1. The charge transfer resistance and double layer capacitance are derived from Nyquist plot. The impedance value and phase angle value are derived from Bode plots.



257


Table 1.1. Impedance parameters of Super-elastic Ni-Ti in Artificial Saliva in presence of Almox (250DT) obtained by AC impedance Spectra.

Artificial Saliva

Rt ohm cm2 4.2654x104

Cdl F/cm2 1.195667x10-6

5.36

AS+Almox (250DT) 50ppm

4.8676x104

1.04774x10-6

5.40

AS+Almox (250DT) 200 ppm

1.04407x105

4.88472x10-7

5.57

SYSTEM

Impedance logZ/ohm

Super-elastic Ni-Ti immersed in Artificial Saliva only When Super-elastic Ni-Ti is immersed in Artificial Saliva the Rt value is 4.2654x104 ohm cm2 and Cd1 value is 1.195667x10-6 F/cm2. (Fig.1 , 2).

Figure 1. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva Solution (Nyquist Plot)



258


Figure 2. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva solution (Nyquist Plot Zoomed)

3.2 Corrosion behaviour of Super-elastic Ni-Ti in Artificial Saliva in the presence of 50ppm Almox 250DT When 50 ppm Almox 250DT is added

Rt value increases from 4.2654x104 to

4.8676x104 ohm cm2.Cd1value decreases from 1.195667x10-6 to 1.04774x10-6 F/cm2. This indicates that the corrosion resistance of Super-elastic Ni-Ti increases in presence of 50ppm Almox 250DT (Fig 3, 4.)



259


Figure.3. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva +50ppm Almox 250DT (Nyquist Plot)

Figure 4 . AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva +50ppm Almox (Nyquist Plot Zoomed)



260


3.3 Corrosion behaviour of Super-elastic Ni-Ti in Artificial Saliva in the presence of 200ppm Almox 250DT When 200 ppm Almox (250DT) is added Rt value increases from 4.8676x104 to 1.04407x105 ohm cm2 Cd1 value decreases from 1.04774x10-6 to 4.88472x10-7 F/cm2 This is also supported by the increase in impedance value. (Fig 5, 6).

Figure 5. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva +200ppm Almox (Nyquist Plot)

Figure 6. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva +200ppm Almox (Nyquist Plot Zoomed)



261


When 50ppm of Almox (250DT) is added the log ( Freq/Hz) vs impedance plot [Fig 1- 6] reveals that the impedance value sharply decreases as frequency increases. The slope of the straight line is in the low frequency region is nearly 0.5.This is characteristic of a system having very high protective efficiency [11-16]. Similar observation is made in presence of 200ppm of Almox (250DT) also. Thus AC impedance spectra reveal that in presence of Almox (250DT) the corrosion resistance of Super-elastic Ni-Ti increases.

Figure 7-8. AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva solution (Bode Plot)



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Figure 9-10 AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva solution (Bode Plot)

Figure 11-12 . AC impedance spectrum of Super elastic Ni-Ti immersed in Artificial Saliva +200 ppm Almox 250 DT (Bode plot)



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It is concluded that people having orthodontic wires made of Super elastic Ni-Ti can take orally Almox 250DT without any hesitation. 4. Conclusion Corrosion Resistance of Super Elastic Nickel-Titanium alloy in artificial saliva, in the absence and presence of a Tablet, namely, Almox 250mg has been evaluated by AC Impedance Spectra. It is observed that Almox 250mg is added to artificial saliva, Charge transfer resistance of Super Elastic Nickel-Titanium alloy increases, in presence of 200 ppm Almox 250mg. Similar observation is made in presence of 200 ppm of Almox 250mg also. Hence it is concluded that people having orthodontic wires made of Super Elastic Nickel-Titanium alloy, can take the Tablet Almox 250mg without any hesitation, because in its presence corrosion resistance of Super Elastic Nickel-Titanium alloy increases. 5. References 1. Castaneda, I. E., Gonzalez-Rodriguez, J. G., Colin, J., Neri-Flores, M .A., J. Solid State Electrochem, 2010, 14(7),1145. 2. Zhou, W., Shen, T., Aung, N. N., Corros. Sci., 2010, 52(3),1035. 3. Shukla, A. K., Balasubramaniam, R., Corros. Sci,2006 ,48(7),1696. 4. Sun, D., Wharton, J. A., Wood, R .J .K., Tribology Int., 2009,42(11), 1595. 5. Sun, D., Wharton, J. A., Wood, R. J .K., Ma, L., Rainforth, W.M., Tribology Int., 2009,42(1),99. 6. Daniel, M., Cailean, A., Bolat, G., Creţescu, I., Sutiman, D.Stud.Univ. BabesBolyai. Chem., 2009, 1, 93. 7. Song, Y., Shan, D., Chen, R., Zhang, F., Han, E.-H., Mater.Sci.Eng C, 2009, 29(3), 1039. 8. Tutunaru, B., Samide, A. P., Preda, M., Rev. Chim, 2007,58(10),923. 9. Hsu, R. W.-W., Yang, C.-C., Huang, C.-A., Chen, Y.-S.,Mater.Chem. Phys, 2004, 86(2), 269. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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10. Peng, P., Kumar, S., Voelcker, N. H., Szili, E., Smart, R. St.C.,Griesser, H. J., J. Biomed. Mater. Res - Part A, 2006, 76 (2),347. 11. Ziebowicz, A., Walke, W., Barucha-Kepka, A., and Kiel, M., J.Achieve. Mater. Manufact. Eng, 2008, 27, 151-154. 12. Rajendran, S., Paulraj, J., Rengan, P., Jeyasundari, J and M. Manivannan, J. Dent. Oral .Hyg, 2009, 1, 1-8. 13. Rajendran, S., Uma, V., Krishnaveni, A., Jeyasundari, J.,Shyamaladevi, B., and Manivannan, M., Arab. J. Sci. Eng,2009, 34(2C), 147-158. 14. Koike, M., Martinez, K., Guok, L., Chahine, G., Kovacevic, R.,Okabe, T., Mater. Lett., 2011, 27, 677. 15. Anwar, E. M., Kherialla, L. S., Tammam, R. H., Oral Implant,2011, 37, 309. 16. Rajendran, S., Chitradevi, P., John, M .S., Krishnaveni, A.,Kanchana, S., Lydia Christy, J., Nagalakshmi, R.Narayanasamy, B., Zastit. Mater. 2010, 51, 149. 17. Saranya, R., Susai Rajendran, Krishnaveni, A., Jeyasundari, J.,Eur. Chem. Bull., 2013, 2(6), 389. 18. Shyamaladevi, B., and Rajendran, S., Eur Chem Bull., 2012, 1(2),503-510. 19. R. Saranya, S. Rajendran, A. Krishnaveni, M. Pandiarajan and R. Nagalakshmi a. “Corrosion Resistance of Metals and Alloys in Artificial Saliva – An overview” , b. Eur. Chem. Bull. 2013, 2(4), 163-170 20. A. Ziebowicz, W. Walke, A. Barucha-Kepka and M. Kiel, “Corrosion Behaviour of Metallic Biomaterials Used as Orthodontic Wires”,

Journal of Achievements in

Materials and Manufacturing Engineering, 27(2008), pp. 151-154. 21. A.C. Vieira, A.R. Ribeiro, L.A. Rocha, and J.P. Celis, “Influence of pH and Corrosion Inhibitors on the Tribocorrosion of Titanium in Artificial Saliva”, WEAR, 261(2006), pp.994-1001.



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22. V. Raman, S. Tamilselvi, S. Nanjundan and N. Rajendran, “Electrochemical Behaviour of Titanium and Titanium Alloy in Artificial Saliva”, Trends Biomater. Artif. Organs, 18(2005), pp.137-140. 23. S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari, M. Manivannan,

“Corrosion

Behaviour of Metals in Artificial in Presence of Spirulina Powder”, Journal of Dentistry and Oral Hygiene, 1(2009), pp. 1-8. 24. S. Rajendran, V. Uma, A. Krishnaveni, J. Jeyasundari, B. Shyamaladevi, M. Manivannan, (2009) “Corrosion behaviour of metals in Artificial Saliva in presence of DD-Glucose”. Arabian Journal for Science and Engineering, 34(2C) 147-158.




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CYCLIC VOLAMMETRY STUDY OF CARBON STEEL IN SEA WATER IN THE PRESENCE OF TYROSINETYROSINE Zn2+ SYSTEM S. GOWRI1

CYCLIC VOLAMMETRY STUDY OF CARBON STEEL IN SEA WATER IN THE PRESENCE OF TYROSINETYROSINE Zn2+ SYSTEM S. GOWRI1 GOWRI *, J. SATHIYABAMA1, S. RAJENDRAN

1. PG and Research Department of Chemistry, Corrosion Research Centre, GTN Arts College, Dindigul-624 624 005, TamilNadu, TamilNadu India. Email: [email protected]

ABSTRACT The inhibition behavior of Tyrosine –Zn2+ in controlling corrosion of carbon steel immersed in sea water was evaluated by weight loss method and cyclic voltammetry study. The formulations consisting of 250 ppm of Tyrosine and 15 ppm of Zn2+ have 92% of inhibition efficiency. Surface evaluation technique like FTIR is used to determine the nature of the protective film formed on the metal surface. The protective protective film consists of Fe2+ – Tyrosine complex, Zn2+ – Tyrosine complex and Zn(OH)2. SEM analysis reveals that the protective film is formed on the metal surface. Cyclic voltammetry study reveals that the protective film is more compact and stable even in 3.5% NaCl environment. Keywords: AFM, Amino acids, Carbon Steel, Electro chemical techniques, FTIR,Tyrosine, FTIR, SEM. 1. Introduction Corrosion inhibitors have long been used for daily operation of recirculating cooling water system, industrial acid cleaning, oil well acidification, and descaling due to their economical and Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.

Int J Nano Corr Sci and Engg 3(4)(2016) 267-279 267 Editors: Dr S Rajendran, A Christy Catherine Mary

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CYCLIC VOLAMMETRY STUDY OF CARBON STEEL IN SEA WATER IN THE PRESENCE OF TYROSINE- Zn2+ SYSTEM S. GOWRI1

efficient properties [1–3]. Organic compounds are recognized as effective inhibitors of the corrosion of many metal and alloys. The efficiency of an organic compound as a corrosion inhibitor is closely associated with the chemical adsorption [4-8]. Among the several methods to save the metals from corrosion, the use of inhibitors has found wide attention both in academia and industries. The corrosion inhibitors are generally used to protect metals against the attack of the acid solutions, which are widely used in acid pickling, industrial cleaning, acid descaling, oilwell acidizing, etc. Organic compounds containing nitrogen, sulfur and oxygen have been widely used as potential corrosion inhibitors in acid solutions [9-11].These compounds prevent corrosion either by getting adsorbed, or by forming a protective layer or an insoluble complex on the metal surface, thus blocking the active corrosion sites. However, most of the organic compounds are synthetic chemicals, expensive and very hazardous to both human beings and the environments, and need to be replaced by non toxic and environmental friendly compounds. The amino acids which contain carboxyl and amino functionalities bonded to the same carbon atom are non-toxic, relatively cheap and easy to produce in purities greater than 99%. It has been shown by various authors that some amino acids can act as corrosion inhibitors, which has generated an increasing interest in these compounds as substitutes to conventional corrosion inhibitors that are usually toxic [12-17]. The inhibition effect of three amino acids, namely, alanine, glycine and leucine, against steel corrosion in HCl solutions has been investigated by potentiodynamic polarization method. The inhibition effect was found to range from 28-91% [18]. The corrosion inhibition of Fe in 1 M HCl using twenty two different common amino acids and four related compounds has been investigated using potentiodynamic polarization curves [19]. In general, amino acids with longer hydrocarbon chains showed greater inhibition. Additional groups or groups which increased electron density on alpha amino group also increased the inhibition efficiency. The present work is under taken



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1. To evaluate the inhibition efficiency of Tyrosine- Zn2+ system in controlling corrosion of carbon steel immersed in the absence and presence of Zn2+ by weight loss method. 2. To investigate the mechanistic aspects of corrosion inhibition by electrochemical studies like cyclic voltammetry. 3. To analyses the protective film by FTIR and SEM. 2.EXPERIMENAL 2.1. Preparation of specimen Carbon steel specimens [0.0267 % S, 0.06 % P, 0.4 % Mn, 0.1 % C and the rest iron] of dimensions 1.0 cm x 4.0 cm x 0.2 cm were polished to a mirror finish and degreased with trichloroethylene. 2.2. Weight-loss method Carbon steel specimens in triplicate were immersed in 100 ml of the sea water containing various concentrations of the inhibitor in the presence and absence of Zn2+ for one day. The weight of the specimens before and after immersion was determined using a Shimadzu balance, model AY62. The corrosion products were cleansed with Clarke’s solution [20]. The inhibition efficiency (IE) was then calculated using the equation: IE = 100 [1- (W2 / W1)] % Where W1 = corrosion rate in the absence of the inhibitor. W2 = corrosion rate in the presence of the inhibitor. 2.3. Cyclic Voltammetry Cyclic voltammograms were recorded in VersaSTAT MC electrochemical system. A threeelectrode cell assembly was used. The working electrode was carbon steel. The exposed surface area was 1 cm2. A saturated calomel electrode (SCE) was used as the reference electrode and a rectangular platinum foil was used as the counter electrode. The cyclic voltammetry curves were recorded in the scan range of −1.8 to −1.8 V (SCE) with a scan rate of 20 mV s−1. 2.4. Surface examination study Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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The carbon steel specimens were immersed in various test solutions for a period of 1 day. After 1 day, the specimens were taken out and dried. The nature of the film formed on the surface of the metal specimen was analyzed by a surface analysis technique 2.5. Fourier Transform Infrared Spectra (FTIR) The FTIR spectra were recorded in a Perkin-Elmer-1600 spectrophotometer. The film formed on the metal surface was carefully removed and mixed thoroughly with KBr making the pellet. 2.6. Scanning electron microscopic studies (SEM) The carbon steel immersed in blank solution and in the inhibitor solution for a period of one day was removed, rinsed with double distilled water, dried and observed in a scanning electron microscope to examine the surface morphology. The surface morphology measurements of carbon steel were examined using JEOLMODEL6390 computer controlled scanning electron microscope.

3. RESULTS AND DISCUSSION 3.1. Analysis of results of the weight loss method The inhibition efficiencies of Tyrosine controlling corrosion of carbon steel is immersed in sea water for a period of one day in the presence and absence of Zn2+ are given in Table 1. It can be seen from the data obtained that, Tyrosine alone some IE, whereas Zn2+ alone is found to be corrosive. When a given concentration of Tyrosine is combined with Zn2+, it is found that the inhibition efficiency increasing with increases in the concentration of Tyrosine. However, the formulations consisting of 250 ppm of Tyrosine and 15 ppm of Zn2+ shows 92% of IE. This suggests a synergistic effect exists between Tyrosine -Zn2+ system [21-25]. Table 1. Corrosion Rates (CR) of Carbon Steel immersed in Sea water in the presence and absence of inhibitor Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Tyr

Zn2+ ( 0ppm)

Zn2+ (15ppm)

(ppm) IE %

CR

IE%

CR mmpy

mmpy 0

-

0.1809

41

0.1067

50

23

0.1392

44

0.1013

100

26

0.1339

54

0.0832

150

32

0.1230

58

0.0759

200

42

0.1049

78

0.075

250

56

0.0796

92

0.0145

3.2. Analysis of FTIR Spectra: FTIR spectrometer is a power instrument that is used to determine the type of bonding for organic inhibitors adsorbed on the metal surface. FTIR spectra have been used to analyze the protective film formed on metal surface. The FTIR spectrum of pure tyrosine shown in fig 1a. The CN stretching frequency appears at 1130 cm-1. The C=O stretching frequency of carboxyl group appears at 1689 cm-1 .The NH stretching frequency appears at 2947 cm-1 .The FTIR spectrum of the film formed on the metal surface after immersion in the sea water for 1 day containing 250 ppm of L-tyr and 25 ppm of Zn2+ is shown in fig1b. The CN stretching frequency has shifted from 1130 to1095 cm-1. The C=O stretching frequency shifted from 1689 to1630cm-1. The NH stretching frequency shifted from 3290 to 3422 cm-1. This indicates that the nitrogen atom of L-tyr has coordinated with Fe2+ formed on the metal surface resulting in the formation of Fe2+- L-tyr complex on the anodic sites of the metal surface. The peak at 1369 cm-1 is due to Zn-O stretching. The stretching frequency due to –OH appears at 3105cm-1. Thus FITR study



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leads to the conclusion that the protective film consist of Fe2+ - L-tyr complex and Zn (OH)2 on the metal surface.[26, 27] Fig. 1a FTIR Spectrum of pure Tyrosine Fig.1b. FTIR spectrum of film formed on metal surface after immersion in sea water containing 250ppm of tyrosine and 15 ppm of Zn2+ (1b)

3.3. Clcylicvolammetry Cyclic voltammograms have been used to investigate the corrosion behavior of metals [28-31]. Deyab and keera [31] have analyzed the influence of sulphide, sulphate and bicarbonate anions on the pitting corrosion behavior of carbon steel in formation water containing chloride ions by means of cyclic voltammetry technique. The cyclic voltammgrams were reworked in the presence of increasing amounts (0.1- 0.3 M) of NaCl at a scan rate of 10mVs-1. The anodic response exhibits a well defied anodic peak, followed y a passive region. The anodic peak is due Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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to the ferrous hydroxide [32]. The cathodic sweep shows two cathodic peaks the appearance of cathodic peak around -1.1 V is due to reduction of corrosion product namely, iron oxide to iron. The appearance of cathodic peak around -0.7 V is due to the reduction of pitting corrosion product precipitate on the electrode surface. In the present study cyclic voltammgrams were recorded by immersing the working electrode, mild sreel, 3.5 % NaCl solution. The cyclic voltammgram of mild steel immersed in 3.5% NaCl is shown in fig 2a. It is observed that during anodic scan no peak was observed. A passive state is observed. This can be explained as follows. When the metal dissolves ferrous hydroxide is formed when the concentration of ferrous oxide at the anodic surface exceeds its solubility product, precipitation of oxide occurred on the electrode surface. When the surface is entirely covered with oxide passive film anodic current density does not increases indicating onset of passivation [31]. In the passive state, the Cl- ion can be adsorbed on the base metal surface in competition with OH- ions. As a result of high polarizability of the Cl- ions, the Cl- oins may adsorb preferentially [33]. The cathodic sweeps shows only one peak at -1.12V. This is due to the reduction of corrosion product iron oxide to iron. The peak due to reduction of pitting product is absent. (This reveals that pitting corrosion does not take place under the given experimental conditions). The cyclic voltammogram of mild steel, which has been immersed in sea water for one day and dried, is shown in fig 2b. (Brown iron oxide was observed on the mild steel electrode). It is observed that during anodic sweep no peak appears but a passive region is observed. During the cathodic sweep the peak due to reduction of pitting corrosion product appears at 528, indicating that pitting corrosion takes place. However, the peak due to reduction of corrosion product, iron oxide, appears at -1.133V. The current density increases from -1.148 x10-3 A to -1.172 x10-3 A. This indicates that when mild steel electrode is immersed in sea water for one day, a protective film of iron oxide is formed on the electrode surface. It is stable in 3.5% NaCl solution. The increases the current density is explained as follows. Chloride ion is adsorbed on the passive Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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film. The absorbed chloride ion penetrates the oxide film especially at the flaws and defects in the oxide film [34]. When the penetrated chloride ion reaches the metal surface they promote local corrosion. When the mild steel electrode is immersed in sea water containing 250 ppm of Tyrosine and 15 ppm of zinc for one day, a protective film is formed. It consists of Fe2+- Tyrosine complex, Zn2+ - Tyrosine complex and Zn (OH) 2, as revealed by FTIR spectroscopy. The cyclic voltammgram of carbon steel electrode, deposited with the above protective film, is shown in fig 2c. It is observed that during anodic sweep, dissolution of metal does not take place. This indicates that the protective film is stable and compact. Electrons are not transferred from the metal surface, and a passive region is observed. During cathodic sweep, the peak corresponding to reduction of pitting corrosion product appears at -500 mV. However, the peak due to reduction of iron oxide to iron appears at -1.333 V. The current density increases from -1.148 x10-3 A to -2.264 x10-3 A. The increase in current density may be explained as above. It is observed from the Fig.1a, 1b, 1c that the pitting potentials for the three systems are at -644.4 mV, -755.5 mV, and -550 mV respectively. That is when carbon steel electrode is immersed in the sea water medium; the pitting potential is shifted to more negative side (active side, i.e., -755.5 mV). It accelerates corrosion because the protective film formed is porous and amorphous. When the electrode is immersed in the inhibitor medium, the pitting potential is shifted to the noble side, i.e., -550 mV. This indicates that the passive film found on the metal surface in the presence of inhibitors is compact and stable. It can withstand the attack of chloride ion present in 3.5 NaCl.



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Fig. 2a Cyclic voltammgram of carbon steel immersed in 3.5% NaCl

Fig. 2b Cyclic voltammogram of carbon steel immersed in sea water for one day



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Figure 2c. Cyclic voltammgram of carbon steel electrode, deposited with the protective film

3.4. SEM Analysis of Metal Surface The SEM image of magnification (X2000) of carbon steel specimen immersed in sea water for 1 day in the absence and presence of inhibitor system are shown in Figure 3 images (b,c) respectively. The SEM micrographs of polished carbon steel surface (control) in Figure.2 (a) image shows the smooth surface of the metal. This shows the absence absence of any corrosion products formed on the metal surface. The SEM micrographs of carbon steel surface immersed in sea water in Figure.2 image (b) shows the roughness of the metal surface which indicates the corrosion of carbon steel in sea water. Fig 3 image mage (c) indicates that in presence of 250 ppm of Tyrosine and 15 ppm of Zn2+ mixture in sea water, the surface coverage increases which in turn results in the formation of insoluble complex on the surface of the metal (Tyrosine-Zn (Tyrosine 2+ inhibitor complex) and the surface is covered by a thin layer of inhibitors which control the dissolution of carbon steel. Such results have been reported earlier [23, 35].



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(a)

(b)

(c) Fig 3.. (a) Polished carbon steel (control) – Magnification2000 (b) Carbon steel immersed in sea water (c) Carbon steel immersed in sea water containing 250 ppm of Tyrosine and 15 ppm o of Zn2+ 4 Reference 1. K.D. Demadis, E. Mavredaki, A. Stathoulopoulou, E. Neofotistou, C. Mantzaridis, “Industrial Industrial water systems: problems, challenges andsolutions for the process industries”, Desaln, 213, (2007), pp. 38-46. 2. M. Behpour, SM. Ghoreishi, A. Gandomi-Niasar, N. Soltani, M.Salavati-Niasari, M. “The The inhibition of mild steel corrosion in hydrochloric acid media by two Schiff base compounds”, J Mat Sci. Sci 44 (10), (2009), pp. 2444-2453.



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3. G. Bereket, A. Yurt “The inhibition effect of amino acids and hydroxy carboxylic acids on pitting corrosion of aluminum alloy 7075”, Corr Sci, 43 (6), (2001), pp. 1179-1195

4. A. Ketsetzi, A. Stathoulopoulou and K.D. Demadis, ”Being "green" in chemical water treatment technologies: issues, challenges and developments”, Desaln, 223, ( 2008), pp. 487-93 5. J.D. Talati, M .N. Desai, N.K. shah, “Meta-Substituted aniline-N-salicylidenes as corrosion inhibitors of zinc in sulphuric acid”, Mat Chem and Phy, 93, (2005), pp. 54–64 6. A. Srhiri, M. Etman, F. Dabosi, “Electro and physicochemical study ofcorrosion inhibition of carbon steel in 3 % NaCl by alkylimidazoles”,Electrochimca Acta, 41, (1996), pp. 429-437 7. M. Vracar Lj. D.M. Drazic, “Adsorption and corrosion inhibitive propertiesof some organic molecules on iron electrode in sulfuric acid” , Corr Sci, 44, (2002),pp.1669– 1680 8. D. Prakash Rajesh Kumar Singh, Ranju Kumar, “Corrosion inhibition of mild steel in 20% HCl by some organic compounds”, Indian Journal of Chemical Technology, 13, (2006), pp. 555-560. 9. M. Lagrenee, B. Mernari, M. Bouanis, M. Traisrnel, F. Bentiss, Corros. Sci.44, (2002), pp. 573. 10. M.A. Quraishi, R. Sardar, Corr. 58, (2002), pp. 748. 11. M.A. Quraishi, S. Khan, J. Appl. Electrochem. 33, (2003), pp. 233. 12. S. Bilgic, Korozyon, 13, (2005), pp. 3. 13. A.B. Silva, S.M.L. Agostinho, O.E. Barcia, G.G.O. Cordeiro, E. D’Elia, Corros. Sci. 48, (2006), pp. 3668. 14. L. Toufari, A. Kadri, A. Khalifa, N. Aimeeur, N. Benbrahim, J. Eng. Appl. Sci. 3 (a) (2008), pp. 688. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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15. E.E. Oguzie, Y. Li, F.H. Wang, J. Electrochim. Acta. 53, (2007), pp. 909. 16. S.A. Umoren, I.B. Obot, N.O. Obi-Egbedi, J. Mater. Sci. 44, (2009) 274. 17. M.S. Morad, J Appl. Electrochem. 38 (2008) 1509. 18. H. Ashassi-Sorkhabi, M.R. Majidi, K. Seyyedi, Appl. Surf. Sci. 225, (2004), pp. 176. 19. V. Hluchan, B.L. Wheeler, N. Hackerman, Werkst. Korros. 39 (1988), pp. 512. 20. D.C. Silverman, D.J. Kalota. F.S. Stover, “Technical note: Divergent effects of Nacyl glutamates on corrosion of aluminum and magnesium alloys”, Corr, 58(2), ( 2002), pp. 99-102. 21. S. Gowri, J. Sathiyabama S. Rajendran and J. Angelin Thangakani “ Self assembling monolayer of Glycine on carbon steel”, Eur chem bull, 2(4), (2013), pp. 214-219 22. S. Gowri, J. Sathiyabama S. Rajendran and J. Angelin Thangakani

“ corrosion

inhibition by Trytophan – Zn2+ system for carbon steel in sea water”, European chemical bulletin, 2(6), (2013), pp. 355-360 23. S. Gowri, J. Sathiyabama S. Rajendran, “The Inhibitive Effect of Glutamic Acid on the Corrosion of Carbon Steel in Sea Water” Int J Chem Tech Res. 5(1), (2013), pp. 347-352. 24. V. Johnsirani, J. Sathiya bama, S. Rajendran, T. Shanthi, T S. Muthumahala, A. Krishnaveni, “Inhibitive Action of Malachite Green”

Bulgarian Chemical

Communication, 44( 1), (2012), pp41-51. 25. M. Sangeetha, S. Rajendran J. Sthiyabama, A. Krishnavani, P. Shanthy N. Manimaran. B. Shamaladevi, “Corrosion Inhibition by an Aqueous Extract of Phyllathus Amarus”, Por Elecchimi Acta, 29( 6), (2011), pp. 429-444.



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Correlation between Quantum Chemical Parameters of Aminoacid inhibitors and their corrosion inhibition efficiencies

J. AngelinThangakani1

Correlation between Quantum Chemical Parameters of Aminoacid inhibitors and their corrosion inhibition efficiencies J. AngelinThangakani1, S. Rajendran2 and J. Sathiabama3 [a]C.E.O.A. Matric Higher Secondary School, Madurai Madurai–625 625 017, Tamil Nadu, India, e_mail : [email protected] [b] Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul women 624 005,Tamil ,Tamil Nadu, India. Email: [email protected] [c]Corrosion Research Centre, Department of Chemistry, GTN Arts College, Dindigul – 624 005, Tamil Nadu, India. Abstract Corrosion Inhibition and efficiencies of aminoacids such as L L-Lysine Lysine and L-Valine L in well water have been calculated by weight loss method. The mechanistic aspects have been studied by Polarization study, AC impedance spectra and AFM. By using Density Functional Fu Theory (DFT) various quantum chemical parameters such as EHOMO, ELUMO, energy gap, electron affinity, Ionisation potential, absolute electro negativity hardness, softness and fraction of electron transferred from the inhibitor to metallic surface have been calculated. The theoretical results were found to be consistent with the experimental data generated. Keywords : Corrosion inhibition, aminoacid inhibitors, DFT, quantum chemical parameters. 1. Introduction A corrosion rrosion inhibitor is a chemical compound that, when added to a liquid or gas, decreases the corrosion rate of a material, typically a metal or an alloy. Inhibitors often work by adsorbing themselves on the metallic surface, protecting the metallic surface by forming a film. Inhibitors are normally distributed from a solution or dispersion. The scientific and technical corrosion literature has descriptions and lists of numerous chemical compounds that exhibit inhibitive properties.

Of these, only very fe few w are actually used in practice.

280 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, amaraipadi, Dindigul, India.


Correlation between Quantum Chemical Parameters of Aminoacid inhibitors and their corrosion inhibition efficiencies J. AngelinThangakani et al.,

Considerations of cost, toxicity, availability and environmental friendliness are of considerable importance. Neverthless, the use of inhibitors like chromates [1], nitrite [2] and aromatic heterocyclic compounds [3] to the optimum level, may pose health hazards and hence environmentally safe inhibitors [4-6] are much sought ofter. Scientists have shown that the use of eco-friendly inhibitors like aminoacids [6-13] on metal corrosion.

The

aminoacids like L-Lysine and L-Valine have brought excellent results as they are found to be bio-degradable, non-toxic, cost-effective and soluble in aqueous media.

The research

presents some studies about the capability of aminoacids to prevent corrosion in iron [14], steel [15-17], aluminium [18, 19], nickel [20] and copper [21-25]. Polarization and AC impedance Spectra [26-30] and AFM [31] have been studied by using aminoacids. The adsorption of aminoacids on carbon steel in an acidic environment has been researched by Akiyama et al. [32].Density Functional Theory is used in Physics, Chemistry and material Science to study the electronic structure of many atoms, molecules and the condensed phase. The name density functional theory comes from the use of functional of the electron density. EHOMO and ELUMO are known as Highest Occupied Molecular Orbital Energy and Lowest Unoccupied Molecular Orbital Energy respectively. The energy difference between these is termed as HOMO – LUMO gap. The difference in energy between these two frontier orbitals are used to study the strength and stability of transition metal complexes, as well as the colours they produce in solution. The aim of this study is, 

Compare the inhibition efficiencies of various aminoacid inhibitors by weight loss method.



To analyse the mechanistic aspects by AC impedance and potentiodynamic polarization studies.



To study the surface morphology by AFM.



To study the various quantum chemical parameters such as EHOMO, ELUMO, energy gap, electron affinity, ionization potential, absolute electronegativity, hardness, softness and fraction of electron transferred from the inhibitor to metallic surface by Density Functional Theory.

2. Experimental Procedure 2.2 Preparation of specimens Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Carbon steel specimens (0.0267% S, 0.067% P, 0.4% Mn, 0.1% C and the rest iron) of the dimensions 1.0 cm × 4.0 cm × 0.2 cm were polished to mirror finish and degreased with trichloroethylene and used for weight loss method and surface examination studies. 2.3 Weight loss method Carbon steel specimens, in triplicate were immersed in 250 ppm of aminoacids in the presence and absence of Zn2+ (as ZnSO4, 7H2O) for a period of one day. The corrosion products were cleaned with Clarke`s solution [33]. The weight of the specimens before and after immersion was determined using Shimadzu balance AY62. The corrosion inhibition efficiency was calculated with equation (1) IE = 100 [ I – ( W2/W1) ]%

------ (1)

Where W1 is the corrosion rate in the absence of the inhibitor and W2 is the corrosion rate in the presence of inhibitor. 2.4 Potentiodynamic polarization study Potentiostatic polarization studies were carried out using a CHI electrochemical impedance analyzer, model 660 A. A three-electrode cell assembly was used. The working electrode was a rectangular specimen of carbon steel with one face of the electrode (1 cm2 area) exposed and the rest shielded with red lacquer. A saturated calomel electrode (SCE) was used as the reference electrode and a rectangular platinum foil was used as the counter electrode. Polarization curves were recorded using IR compensation. The results, such as Tafel slopes, and Icorr, Ecorrand LPR values were calculated. During the polarization study, the scan rate (v/s) was 0.01; hold time at Ef(s) was zero and quit time(s) was 2. 2.5 AC impedance measurements A CHI electrochemical impedance analyzer (model 660A) was used for AC impedance measurements. A time interval of 5 to 10 minutes was given for the system to attain its open circuit potential. The real part Z’ and imaginary part Z” of the cell impedance were measured in ohms at various frequencies. The values of the charge transfer resistance R1, double layer capacitance Cdl and impedance value were calculated. Rt = (Rs+ Rt) – Rs

------------- (3)

where Rs= solution resistance Cdl= ½ π Rtfmax

------------- (4)

282 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.



Where fmax= maximum frequency AC impedance spectra were recorded with initial E(v) = 0; high frequency (Hz) = 1; amplitude (v) = 0.05; and quiet time(s) = 2. 2.6 Atomic Force Microscopy Atomic force microscopy is a powerful technique for gathering of roughness statistics from a variety of surfaces. AFM is becoming an accepted method of roughness investigation. [3440]. All atomic force microscopy images were obtained in a VECCO lab incorporation AFM instrument operating in contact mode in air. The scan size of all the AFM images are 05 m x 05 m areas at a scan rate of 6.68 m/second. 2.7 Computational methods All geometry optimizations and quantum chemical calculations were performed using density functional theory (DFT) utilizing the Becke's three parameter and the Lee–Yang–Parr correlation functional theory (B3LYP) [41]. The 6-31 + G(d,p) basis set was also selected for the study. Density functional theory (DFT) has found wide applicability in the analysis of the characteristics of the inhibitor/metal surface mechanisms and in the description of the structural nature of the inhibitor on the corrosion process [42,43]. Moreover, there is a good agreement between experimental results and the quantum chemical parameters computed using DFT [43]. Some of the chemical parameters calculated include electron affinity (A), ionization potential (I), electronegativity (X) the energy gap (E), hardness (), Softness (1/) and fraction of electron transferred from the inhibitor to metallic surface (N). All calculations were done by using the Gaussian09 program [44]. Schematic structures were drawn using the ChemOffice package in the UltraChem 2010 version while optimized structures were drawn using the gaussView5 program. Table 1 : Molecular formula of aminoacids. Aminoacids

Molecular Formula

L-Lysine

C6H14N2O2

L-Valine

C6H11NO2

3 Results and Discussion Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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3.1 Analysis of results of weight loss method Inhibition efficiencies and (IE %) of various systems like L L-Lysine Lysine – Zn2+ and L-Valine – Zn2+ in controlling corrosion of carbon steel immersed in well water in the presence and absence of inhibitor system (Inhibition period = 7 days) are given in the table 2 comparitively. Table 2 : Corrosion rates (CR) of carbon steel immersed in well water in the presence and absence of inhibitor system and the inhibition efficiencies (IE) obtained by weight loss method.

System

CR, mdd

IE%

Blank

240.29

15

L-Lysine Lysine (250 ppm) + Zn2+ (50 ppm)

5.65

97

L-Valine Valine (250 ppm) + Zn2+ (50 ppm)

8.48

96

250 200 150 100

CR, mdd

50

IE%

0 Blank L-Lysine (250 ppm) + Zn2+ (50 ppm)

L-Valine (250 ppm) + Zn2+ (50 ppm)

Fig. 1 : Corrosion Rates (CR) and (IE) of Various Systems.

284 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, amaraipadi, Dindigul, India.



From the above Table 2, it is observed that L-Lysine (250 ppm) + Zn2+(50 ppm) system has good inhibition efficiency. The Inhibition efficiency of aminoacids are in the following order : L-Lysine (250 ppm) + Zn2+ (50 ppm) > L – Valine (250 ppm) + Zn2+ (50 ppm) The reason for the high Inhibition Efficiency of L-Lysine is due to the presence of elements in the system. 3.2 Analysis of potentiodynamic polarization study (pH = 3) Polarization study has been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process [45-50]. If a protective film is formed on the metal surface, the linear polarization resistance value (LPR) increases and corrosion current value (Icorr) decreases. The potentiodynamic polarization curves of carbon steel immersed in well water in the presence and absence of inhibitors are shown in fig. 2 (a), (b) and fig. 3(a), (b) The corrosion parameters are given in table 3. When carbon steel was immersed in well water the corrosion potential was -502 mV vs SCE. When L-Lysine (250 ppm) + Zn2+ (50 ppm) were added to the above system the corrosion potential shifted to the cathodic side -538 mV vs SCE. For L – Valine (250 ppm) + Zn2+ (50 ppm) the corrosion potential shifted to – 517 mV vs SCE respectively. Further, the LPR value increase for L-Lysine (250 ppm) + Zn2+ (50 ppm) system from 12948.8 ohm cm2 to 35923.9 ohm cm2. For L – Valine (250 ppm) + Zn2+ (50 ppm), have LPR value 33183.9 ohm. cm2 respectively. L-Lysine (250 ppm) + Zn2+ (50 ppm) system has high LPR value than L-Valine inhibitor systems. The corrosion current decreases from 3.521 ×

10-6

A/cm2

to

L-Lysine (250 ppm) + Zn2+ (50 ppm).

1.224

×

10-6

A/cm2for

For L – Valine (250 ppm) + Zn2+ (50 ppm),

has corrosion current value 1.334 × 10-6 A/cm2. L – Lysine (250 ppm) + Zn2+ (50 ppm) system has least corrosion current value than L-Valine inhibitor systems. Table 3 : Corrosion parameters of carbon steel immersed in well water in the presence and absence of inhibitor system obtained from potentiodynamic polarization study.

System

Ecorr mV vs SCE

bc, mV/decade

ba, mV/decade

Icorr, A/cm-2

LPR, ohm cm2



285



Well water

-502

194.3

227.6

3.521×10-6

12948.8

Well water + L-Lysine (250 ppm) + Zn2+ (50 ppm)

-538

189.3

217.1

1.224×10-6

35923.9

Well water + L-Valine (250 ppm) + Zn2+ (50 ppm)

-517

190.5

218.5

1.334×10-6

33183.9

The results are in agreement with weight loss method.

a b

Fig. 2 : Polarisation curves Carbon steel immersed in various test solutions (a) Well Water (b) L-Lysine (250 ppm) + Zn2+ (50 ppm)




a b

Fig. 3 : Polarisation curves Carbon steel immersed in various test solutions (a) Well Water (b) L – Valine (250 ppm) + Zn2+ (50 ppm) 3.3 Analysis of AC impedance spectra AC impedance spectra have been used to confirm the formation of protective film on the metal surface [51-53]. If a protective film is formed on the metal surface, charge transfer resistance (Rt) increases; double layer capacitance value (CdI) decreases and impedance log (z/ohm) value increases. The phase angle also increases. The AC impedance spectra (Nyquist plots) of carbon steel immersed in various solutions are shown in fig. 4 (a), (b) and fig. 5(a), (b). When the carbon steel is immersed in well water the Rtvalue (Nyquist plot) is 4737 ohm.cm2. After adding the inhibitor system L-Lysine (250 ppm) + Zn2+ (50 ppm) the Rt value increases to 7304 ohm cm2. For L – Valine (250 ppm) + Zn2+ (50 ppm), the Rt value is 7245 ohm. cm2. L-Lysine (250 ppm) + Zn2+ (50 ppm) has greater value than L-Valine systems. On the otherhand, when the carbon steel is immersed in well water the CdI value (Nyquist plot) is 1.056 × 10-9 F/cm2. For L-Lysine (250 ppm) + Zn2+ (50 ppm) the value is decreased to 0.6845 × 10-9 F/cm2. For L-Valine (250 ppm) + Zn2+ (50 ppm), system the CdI value is 0.6901 × 10-9 . L- Lysine (250 ppm) + Zn2+(50 ppm) has least value L-Valine system. Further, when the carbon steel is immersed in well water the Impedance value log (Z/ohm) (Bode Plot) is 3.886. The impedance spectra (Bode plot) are shown in fig. 6 for LLysine (250 ppm) + Zn2+ (50 ppm) the value is increased to 4.040. for L – Valine (250 ppm) Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


287



+ Zn2+ (50 ppm) system the value is 4.039. L-Lysine (250 ppm) + Zn2+ (50 ppm) has high value than L-Valine system. These values are shown in Table 4.

b a

Fig. 4 : AC impedance spectra (Nyquist Plots ) of Carbon steel immersed in various systems. (a) Well Water (b) L-Lysine (250 ppm) + Zn2+ (50 ppm)

b a

Fig. 5 : AC impedance spectra (Nyquist Plots ) of Carbon steel immersed in various systems. (a) Well Water (b) L – Valine (250 ppm) + Zn2+ (50 ppm) Fig. 6 : AC impedance spectra (Bode plots) of Carbon steel immersed in various systems 288 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.



a) Well Water

b) Well water + L-Lysine (250 ppm) + Zn2+ (50 ppm)

c) Well water + L-Valine (250 ppm) + Zn2+ (50 ppm) Table 4: Corrosion parameters of carbon steel immersed in well water in the absence and presence of inhibitor system obtained from AC impedance spectra (pH = 3).

Nyquist plot System

Rt

Bode plot

CdI 2

ohm cm

2

F/ cm

Impedance value Log(z/ohm)

Well water

4737

1.056×10-9

3.886

Well water + L-Lysine (250 ppm) + Zn2+ (50 ppm)

7304

0.6845×10-9

4.040



289



Well water + L-Valine (250 ppm) + Zn2+ (50 ppm)

0.6901×10-9

7245

4.039

3.4 Atomic Force Microscopy Characterization AFM is used to investigate the surface morphology of thin films. In this the valuable informations regarding Route Mean Square Roughness (Rq), average Roughness (Ra), and peak to value height (P-V) in nm level are obtained.The AFM images of the surface of polised metal, Polised metal immersed in well water and in various inhibitor environments are shown in fig. 7(a),(b),(c); fig. 8(a),(b),(c); fig. 9(a),(b),(c); fig. 10(a),(b),(c) respectively. The AFM parameters derived from these images are summarized in Table 5.

Table 5 : AFM data for carbon steel surface immersed in inhibited and uninhibited environments.

Samples

Roughness, nm

Maximum peak to valley height (nm)

RMS (Rq)

Average (Ra)

Polished

83.35

62.11

270.90

Well Water

751.72

581.77

1088.30

L-Lysine

499.61

403.64

695.89




561.98

L-Valine

500.33

1015.60

It is observed that for polised metal, the AFM parameters namely Rq, Ra and P-V are low. For corrosive medium surface, these parameters are verified. For various inhibitor systems, these parameters are in between the extreme cases. For the inhibitor systems the roughness increases L-Valine. ine.

in

the

following

order.

L L-Lysine

Cu>SS>Mild Steel>Al.. Key words: Electrochemical hemical method, method wastewater treatment, Methylene Blue dye, decolourisation efficiency

1. Introduction In general, the wastewater generated from textile industries is found to contain high degree of pollutants with high total dissolved solids and suspended solids. The wastewater is highly Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 20162016 St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.

Int J Nano Corr Sci and Engg gg 3(4)(2016) 326 - 336 Editors: Dr S Rajendran, A Christy Catherine Mary

327


colored and viscous due to dyestuff and suspended solids respectively. The textile industry is estimated to consume as much as two-third of the total annual production of dyes[1]. Azo dyes are the largest and most versatile class of dyes and are commonly used to dye various materials such as textiles leathers, plastics, cosmetics and food2. They are the major group of dyes used in the textile industry and contribute between 50-65% of the colours in textile dyes[1,3]. The inefficiencies in the dyeing process result in dyestuff losses between 2-50% to the waste water with the lower limit for basic dyes and the upper for azo dyes. Ultimately these dyes find their way to the environment and end up contaminating rivers and groundwater in the location of the industries[3]. Colours in water bodies reduce light penetration, alter the pH, increase the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) and thereby make aquatic life difficult[4]. Dye house effluents are therefore of serious environmental concern. Several treatments of textile effluents to achieve decolourisation have been reported. These include physiochemical methods such as filtration, specific coagulation, use of activated carbon and chemical flocculation .Some of these methods are effective but quite expensive[5,6]. Although, biotreatment offers a cheaper and environmentally friendlier alternative for colour removal in textile effluents, it has its own demerits. Anaerobic decolourisation of azo dyes produces aromatic amines which are toxic to aquatic life[3] mutagenic to humans and cannot be degraded further under anaerobic conditions [7,8]. It has been reported that the only safe biodegradation method for azo dyes is combined aerobic treatment[9]. However, there are very few reports of aerobic bacteria that can grow with azo compounds2. Electrochemical methods can also be used to decolourise dyes. Recently electrochemical methods[10,11,18,19] and chemical methods[12,13] have been used to decolourize various dye solutions. The present work is undertaken to decolourise an aqueous solution of Methylene Blue (Scheme – 1) dye by electrochemical methods using platinised titanium, mild steel, aluminium, copper and stainless steel as anodes and graphite as cathode



328


Scheme – 1: - Methylene Blue

2. Methodology Dye solution: 50 ppm of Methylene Blue solution was used. 2.1. Decolourisation Process The optical density of the dye solution before and after decolourisation was measured by the instrument Photoelectric Colorimeter -112.Graphite was used as cathode. Platinised titanium /Mild ild steel / Copper/Aluminium /SS were used as anode. The electrolysis was carried out in an undivided cell with a stirring bar (Fig- 1). UV-Visiblee spectra were recorded in a Lam Lamda 35 model. Cathode

:

Graphite

Current Density

:

0.005 A/cm2

Volt

:

4 Volts

Duration of Electrolysis

:

5 mts

Initial OD

:

0.66

Electrolyte

:

3.75 gm of NaCl dissoluted in 100 ml of

:

7.2

dye solution pH of Dye solution Before electrolysis

1.Voltmeter and Ammeter, 2.. Electrodes (Cathode and Anode), Anode) 3.Beaker .Beaker with dye solution solution, 4.Stage. Figure: 1 Schematic diagram of experimental setup Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 20162016 St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.

Int J Nano Corr Sci and Engg gg 3(4)(2016) 326 - 336 Editors: Dr S Rajendran, A Christy Catherine Mary

329


3. Results and Discussion Decolourisation process was carried out in an undivided glass cell, provided with a stirring bar. 100 ml of the dye solution was taken (50 ppm of Methylene Blue. Graphite was used as cathode. One of the metal specimens (platinised titanium / Mild steel /Aluminium etc) was used as anode. 3.75 gm of sodium chloride was added. Current was passed for 5 minutes (4 volts; current density = 0.005 A/cm2). The pH of the dye solution, before and after decolourisation was measured. The optical density was measured before and after decolourisation. The decolourisation efficiency (DE) was calculated using the relation

Percentage decolourization = [Initial O.D - Final O.D / Initial O.D] X 100 DE = [OD1 - OD2 / OD1] X 100 Where OD1 = Optical Density before decolourisation OD2 = Optical Density after decolourisation DE = Decolourization efficiency The results are summarized in Table 1. It is observed that platinised titanium offers the maximum DE of 82%; Cu 68 %; SS 64%; Mild steel offers 56 % and Al 47% Table: 1 Decolourization efficiency of Methylene Blue solution NaCl 3.75 g 4 volt OD After DE electrolysis 0.12 82%

S.NO

Anode

pH after electrolysis

1

Pt/Ti

6.8

2

Cu

6.7

0.21

68%

3

Mild Steel

7.1

0.29

56%

4

Stainless Steel

7.0

0.24

64%

5

Al

7.2

0.35

47%

3.1 UV-Visible absorption spectra Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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UV-visible spectra for untreated (before electrolysis) and treated (after electrolysis) dye solution were recorded. The initial spectrum showed that the wavelength of the maximum absorbance (λ max) in the case of Methylene Blue (before decolourization) the four peaks were appeared at 194nm, 198nm, 270nm, 427nm (Fig.2). After decolourization, only one peak was appeared at 201 nm (Fig.3). It is revealed that the losing absorbing bands over the decolourisation process. This showed that decolourizattion of dye had taken place more effectively. The maximum efficiency of decolourization process is about 82%. The lonely peak in the region of 200-300 nm indicates that the aromatic structure is still there but the intensity is reduced to a great extent. The concentration is negligibly small. The destruction of the aromatic ring is not complete. That is why the decolourisation efficiency is not 100% but only 82%. When there is decolourisation of dye solution, the absorbance decreases. Similar observations have been made by Maria Rivare et al [20] while studying degradation of Reactive Black 5. 3.20 194.06,2.7238 3.0 198.94,2.8228 2.8 270.00,2.6345 2.6 2.4 2.2 2.0 1.8

A

427.00,1.4372

1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.00 190.0

250

300

350

400

450

500 nm

550

600

650

700

750

800.0

Fig.2. UV-Visible spectrum of Methylene Blue (before decolorization)



331

Electrochemical Decolourisation Process of Methylene Blue Dye in the Presence of NaCl at Platinised Titanium Electrode M.Vijayalakshmi, B.Vanmathi A.Sahaya Raja, J. Sathiyabama, V.Prathipa 2.20

2.0

200.83,1.8510

1.8

1.6

1.4

1.2 A 1.0

0.8

0.6

0.4

0.2

0.00 190.0

250

300

350

400

450

500 nm

550

600

650

700

750

800.0

Fig.3. UV-Visible spectrum of Methylene Blue (After decolourization) [Pt/Ti Electrode; 3.75g NaCl ; 4 volt ; DE=82%] 4. Mechanism of decolourisation When sodium chloride solution is electrolysed, positive chloride ion (Cl+) is produced (Figure – 4) .It is highly reactive. It decolorizes the coloured material into colourless product. Now negative chloride is (Cl- ) is produced. It transfers the electrons to the metal surface and hence Cl+ is produced [14,15]. Various other species have also been proposed responsible for the declourisation of dyes. Some of the reactive species proposed are OCl. [14] , OH. Radicals and OCl- [15]; OH., O. and ClOH.[16] and Cl. , Cl2. , ClOH-[17].



332


Figure:4 Electrochemically regenerated Cl+

5. Conclusion The removal of the reactive textile dye Methylene Blue from an aqueous medium by the electrochemical method using platinised titanium, mild steel, aluminium, Copper and stainless steel electrodes have been investigated. It is observed that platinised titanium offers the maximum DE of 82%; Cu 68 %; SS 64%; Mild steel offers 56 % and Al 47%. The decolourisation efficiency is in the decreasing order. Pt/Ti>Cu>SS>Mild Steel>Al. In the case of platinised titanium, the DE is very high 82%. This is attributed to the fact, that this metal readily accepts the electron released by Cl-. Hence Cl+ is produced readily, easily and abundantly. This Cl+ converts the coloured compounds in to colourless products. The decrease in DE of other metals is attributed to the fact that these metals accept the electron from Cl- less readily and produced Cl+ species less readily and slowly. Eletrochemical decolorization of dye solution takes less time than any other decolorization methods. Acknowledgement The authors are thankful to their respective management, Principal, G.T.N.Arts College, Dindigul, Tamil Nadu, India for providing the required facilities for completion of the work. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


333


Refernces [1]. M. Melgoza, A. Cruz and G. Bultron, “Anaerobic / aerobic treatment of colorants present in textile effluents”, Water Sci. Technology, 50 (2004) 149-155. [2]. S. Blumel, H. J. Knackmuss, and A. Stolz, “Molecular cloning and characterization of the gene coding for the aerobic azo reductase from Xenophilusazovorans KF46F”, Applied Environmental Microbial, 68 (2002) 3948-3955. [3]. K.T. Chung and S.E. Stevens, “Decolurization of environmental microorganisms and helminthes”, Environ .Toxicol. Chem., 12 (1993) 2121-2132. [4]. S.O. Ajayi, and O. Osibanjo, “Determination of metals in tree barks as indicators of atmospheric pollution”, Monogra, 1 (1980) 6-86. [5]. TJ.Do., G.Shen., Cawood., R.Jeckins. Biotreatment of textile effluent using Pseudomonas sp.Immobilized on polymer supports.In:Advances in biotechnology for textile processing. Hardin,I.R.,D.E.Akin and J.S.Wilson (Eds). University of Georgia press, Georgia.(2002) 35-45. [6]. J. Maier, A. Kandelbauer, A. Erlacher, A. Cavaco-Paulo and G.M. Gubits, “ A New Alkali – Thermostable Azo reductase from Bacillus Sp. Strain SF”, Applied Environ, Microbial., 70 (2004) 837- 844. [7]. K.T. Chung and C.E. Cerniglia, “Mutagenicity of azo dyes:Structure- activity relationship”, Muta. Res, 277 (1992) 201 - 220. [8]. I. M. C. Goncalves, A. Gomes, R. Bras, M. I. A. Ferra, M. T. P. Amorin and R. S. Porter, “Biological treatment of effluent containing textile dyes”, Coloration Technology., 116 (2000) 393-397.



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[9]. M.E.B. Mabrouk and H.H. Yusef, J. “Decolorization of Fast Red by Bacillus subtilis HM”, Applied Sci. Res., 4 (2008) 262-269. [10]. P. Kariyajjanavar, J. Narayana, Y.A. Nayaka, M. Umanaik, “Electrochemical Degradation and Cyclic Voltametric Studies of textile Reactive Azo dyes Cibacron Navy WB”, Portugalia Electrochimica Acta, 28 (2010), 265-277. [11]. M. Mathewaran, T. Raju, “Destruction of methylene blue by mediated electrolysis using two- phase system”, Safety and Environmental protection, 88(5) (2010) 350355. [12]. B. Mucedo Moturi, M.A.S. Charya, “Influence of Physical and Chemical mutagens on dyes decolorisingMucormucedo”, African Journal of Microbiology Research, 4 (17) 2010 1808-1813. [13]. J. Rodriguez, M.A. Rodrigo, M. Painzza and G. Cerisola, “ Electrochemical Oxidation of Acid yellow 1 using dimond anode”, Journal of Appl. Electrochem., 39 (2009), 2285-2289. [14]. A.I. Del Rio, J. Molina, J. Bonastre, F. Cases, “Study of the electerochemical oxidation and reduction of C.I. Reactive Orange 4 in sodium sulphate alkaline solution”, Journal of Hazardous materials, 172 (1) (2009) 187-195. [15]. S.A.Leonadro , T. T. Thiagoo, L.D. Diogo, C.R.F. Romeu, B.Nerilso and R.B.Sonia, “on the performances of lead dioxide and boron-doped dianal electrodes in the anodic oxidation of simulated was tewater containing the Reactive orange 16 dye”, Electrochimica Acta, 54 (2009) 2024-2030. [16]. M.A. Sanroman, M. Pazos, M.T. Ricrot and C. Cameselle, Decolorisation of textile indigo dye be DC electric current”, Engineering Geology, 77 (2005) 253-261. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[17]. V. Lope- Grimau and M.C. Gutierrez, “Decolourization of simulated reactive dyebath effluents by electrochemical oxidation assisted by UV light”, Chemosphere, 62 (2006) 106-112. [18]. A.Sahaya Raja, V.Prathipa, Optimisation of electrochemical decolourisation of Fast Sulphon Black F dye solution, International Journal of Chemical Concepts, Vol.01, No.03, pp 154-158, 2015. [19]. A. Sahaya Raja, J. Sathiyabama, V. Prathipa, Decolourization of Textile Dye (4-(2Hydroxy-5-Methylphenylazo)Acetanilide) by Electrochemical Method, Journal of Advanced Electrochemistry, Volume 1,Issue 1,2015, Pages 13-15. [20]. Maria Rivera, Marta Pazos, Maria Ángeles Sanromán, Development of an electrochemical cell for the removal of Reactive Black 5, Desalination, Volume 274, Issues 1–3, 1 July 2011, Pages 39–43.




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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3

Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 Author1: Visting Facult, Dyepartment yepartment of Chemistry,Anna universityuniversity University College of Engineering, Dindigul, Tamilnadu, India-624 005. Email: [email protected] Author2: Professor Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India. India-624 005. [email protected] E E-mail:

Author3: Professor & Head, R & D Cetre, Department of Mechanical Engineering, RVS Educational Trust’s Group of Institutions, RVS School of E Engineering ngineering and Technology, Dindigul, Tamilnadu, India-624 India 005. Email: [email protected]

Abstract The inhibition efficiency of glutaric and malonic acid in controlling corrosion of Aluminium in an aqueous solution at pH 10, in the absence and presence of Zn2+ has been evaluated by weight loss method. The formulation consisting of 250 ppm of glutaric acid and 50 ppm of Zn2+ has 95% corrosion inhibition n efficiency and f 250 ppm of malonic acid and 50 ppm of Zn2+ has 90% corrosion inhibition efficiency . A synergistic effect exits between glutaric acid,malonic acid and Zn2+. The mechanistic aspects of corrosion inhibition have been evaluated by polarization polariza study. In the presence of inhibitor , linear polarization resistance increases ;corrosion current Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Wom Women, en, Thamaraipadi, T Dindigul, India.


337

Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 decreases; The protective film has been

analyzed

by UV absorption spectroscopy and

Fluorescence spectra. The surface morphology of the film has been investigated by AFM, SEM and EDAX. The stability and strain or strainless complex has been investigated by HOMO and LUMO study. Keywords:

Corrosion inhibition, Aluminium at pH 10, glutaric acid ,malonic acid,

Fluorescence, FTIR, and UV spectra , AFM, HOMO and LUMO, nanofilm 1. Introduction Aluminum is one of the metals which used in distinct human activities and many of important applications, where it is the second most abundant metal after iron, it has a low atomic mass and negative value of standard electron potential, aluminum potentially attracts as an anodic material for power sources with high energy density. It is used in construction, packing and transportation because of its strength and electrical conductivity. Aluminum is used in electronics due to it is super purity [1]. Although Al has an adhesive protective passivating oxide film, but this film has an amphoteric susceptibility, and consequently the metal dissolves readily in acidic and basic solutions concentrated above and below pH 4-9 [2, 3].Wöhler is generally credited with isolating aluminium (Latin alumen, alum), butalso Ørsted can be listed as its discoverer [4]. Further, Pierre Berthier discoveredaluminium in bauxite ore and successfully extracted it [5]. Charles Martin Hall ofOhio in the U.S. and Paul Héroult of France independently developed the HallHéroult electrolytic process that made extracting aluminium from minerals cheaper, being now the principal method used worldwide. Aluminium is a good thermal and electrical conductor, having 59% of the conductivity of copper, both thermal and electrical. Aluminium is capable of being a superconductor, with a superconducting critical temperature of 1.2 K and a critical magnetic field ofabout 100 Gauss (10 milliteslas) [6].Aluminium is the most widely used nonferrous metal [7]. Global production o faluminium in 2005 was 31.9 million tonnes. It exceeded that of any other metalexcept iron (837.5 million tonnes) [8]. Forecast for 2012 is 42–45 million tons,driven by rising Chinese output [9]. The common aluminium foils and beverage cans are alloys of 92% to 99% aluminium [10].

Aluminium is 100% recyclable



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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 without any loss of its natural qualities. In Europe aluminium experiences high rates of recycling, ranging from 42% of beverage cans, 85% of construction materials and 95% of transport vehicles [11]. Corrosion is the destructive result of reaction between a metal or metal alloy and its environ‐ment [12-14]. Corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper [15]. This corrosion resistance is also often greatly reduced when many aqueous salts are present, particularly in the presence of dissimilar metals. 2. Experimental Section 2.1 Preparation of the specimens Commercial aluminium specimens of dimensions 1.0 x 4.0 x 0.2cm, containing 95% pure aluminium were polished to mirror finish, degreased with trichloroethylene, and used for the mass-loss method . 2.2 Inhibitor solution 1g glutaric acid and malonic acod was dissolved in double distilled water and NaoH solution, and the each solution was made up to 100ml. The pH of the solution is 10 and this solution was used as a inhibitor solution 2.3 Weight loss method Three aluminium specimens were immersed in 100ml of the solution at pH 10 and various concentrations of the inhibitor in the absence and presence of Zn2+ for a period of 1 day. The weight of the specimen before and after immersion was determined using Shimadzu balance AY62.Inhibition efficiency (IE) was calculated from the relationship. IE = 100 [1-W2/W1)] % Where W1 and W2 are the corrosion rates in the absence and presence of the inhibitor, respectively. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 2.4 Potentiodynamic polarization study Polarization study was carried out in a CHI electrochemical work station impedance analyzer model 660A. A three electrode cell assembly was used. The working electrode was Aluminium, A saturated calomel electrode (SCE) was the reference electrode and platinium was the counter electrode. The corrosion parameters such as linear polarization Resistance. (LPR), corrosion potential, Ecorr, corrosion current, Icorr, and Tafel slopes (ba and bc) were measured. 2.5 Altsernating current impedance measurements Polarization study was carried out in a CHI electrochemical work station impedance analyzer model 660A. A three electrode cell assembly was used. The working electrode was Aluminium, A saturated calomel electrode (SCE) was the reference electrode and platinium was the counter electrode. The corrosion parameters such as linear polarization Resistance. (LPR), corrosion potential, Ecorr, corrosion current, Icorr, and Tafel slopes (ba and bc) were measured. 2.6 Atomic Force of microscopy Atomic force microscopy is a powerful technique for gathering statistics from a variety of surfaces. Atomic force microscopy (Veeco diInnova model)was used to observe the samples surface in tapping model, using cantilever with linear tips. The scanning image in the image was 5µm x 5µm and the scan rate was 0.6Hz /seconds 2.7 UV- Visible absorbance spectra The instrument UV spetord S-100 Analytic Jena was used for recording UV visible absorbance spectra 2.8 Fluorescence spectra Fluorescence spectra of solution and film formed on the metal surfaces were also recorded using Jasco F-6300 Spectra fluorimeter. Fluorescence spectroscopy is a type of electromagnetic spectroscopy which analyses fluorescence for a sample. A beam of light at a constant wavelength. This is called an emission spectrum. A emission map measured by recording the emission spectra, resulting from a range of excitation wavelength, by combining them together. 2.9 FTlR Spectra Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 These spectra were recorded with the Perkin Elmer -1600 FTIR spectrophotometer. The FTIR spectrum of the protective film was recorded by carefully removing the film, mixing it with KBr and making the pellet. 2.9 Scanning Electron Microscopic Studies (SEMs) The aluminium specimen immersed in blank and in the inhibitor solution for a period of seven days was removed, rinsed with double distilled water, dried, and observed in a scanning electron microscope to examine the surface morphology. The surface morphology measurement of the aluminium specimen were examined using JOEL -6390 computer –controlled scanning electron microscope. 2.10 Energy Dispersive Analysis of X –Rays (EDX) The aluminium specimen immersed in blank and in the inhibitor solution for a period of seven days was removed, rinsed with double distilled water, dried, and observed in a Energy Dispersive Analysis of X –Rays (EDX) to examine the elements present on the metal surface .The elements present on the metal surface were examined JOEL -6390 computer –controlled Energy Dispersive Analysis of X –Rays (EDX) 2.11 HOMO and LUMO study HOMO and LUMO are the highest occupied molecular orbital

and

lowest unoccupied

molecular orbital, respectively. The energy difference between the HOMO and LUMO is termed the HOMO–LUMO gap. HOMO and LUMO are sometimes referred to as frontier orbitals in Frontier Molecular orbital Theory.

The difference in energy between these

two frontier orbitals used to predict the strength and stability of transition metal complexes, as well as the colors they produce in solution. 3. Results and Discussions 3.1 Analysis of Results of weight loss method The corrosion rate of aluminium in an aqueous solution at pH 10 in the absence and presence of inhibitor obtained by weight loss method are given in Table 1. The inhibition efficiency are also given in Table-1. It is observed from Table -1 that glutaric acid (GA) and malonic acid (MA) has good inhibition efficiency (IE).As the concentration of inhibitor increases, the inhibition Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 efficiency (IE) also increased. As the concentration inhibitor increases, more inhibitor molecules are adsorbed on the metal surface and hence, corrosion protection increases. Corrosive ions are not able to attack the metal surface. 3.2 Influence of Zn2+ on the inhibition efficiency of Glutaric acid (GA) and Malonic acid (MA) The influence of Zn2+ on the IE of GA and MA is given in Table 1 and 2. In the presence of Zn2+ ( 50 ppm) excellent inhibitive property is shown by GA and MA. A synergistic effect exists between GA, MA and Zn2+ For example , 250 ppm of GA has 90% IE, 50 ppm of Zn2+ and250 ppm of MA has 95% IE, 50 ppm of Zn2+ has 13 or 18% IE. But their combination has 95% inhibition efficiency. This suggest that a synergistic effect exist between GA,MA and Zn2+ 3.3 Analysis of polarization curves Polarization study has been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process[16 -28].The potentiodynamic polarization curves of aluminium immersed in various solutions at pH 10 are shown in Figure1. The corrosion parameters such as corrosion potential (Ecorr) , corrosion current (Icorr), Tafel slopes (ba, bc) and linear polarization (LPR) are given in Table 3. When aluminium is immersed in an aqueous solution at pH 10, the corrosion potential is 583 mV vs SCE. When the inhibitors are added, (250ppm of GA and 50ppm of Zn2+) the corrosion potential shifted to anodic side (-434mV vs SCE). A shift of corrosion potential in the noble side is an indication of formation of protective film on the metal surface. Further LPR value increases from 50260 to 10 99482 Ohm cm2 and corrosion current decreases from 5.226 x 10-7 A/cm2 to 2.89510-7 A/cm2. These results suggest that a protective film is formed on the metal surface . When aluminium is immersed in an aqueous solution at pH 10, the corrosion potential is -583 mV vs SCE. When the inhibitors are added, (250ppm of MA and 50ppm of Zn2+) the corrosion potential shifted to anodic side (-415mV vs SCE). A shift of corrosion potential in the noble side is an indication of formation of protective film on the metal surface. Further LPR value increases from 50260 to 85826 Ohm cm2 and corrosion current decreases from 5.226 x 10-7 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 A/cm2 to 3.983 x10-7 A/cm2. These results suggest that a protective film is formed on the metal surface. 3.4 Analysis of AC impedance spectra AC impedance spectra (electrochemical impedance spectra) have been used to confirm the formation of protective film on the metal surface. If a protective film is formed on the metal surface, charge transfer resistance (Rt) increases and double layer capacitance value (Cdl) decreases .The AC impedence spectra of aluminium immersed in various solution are shown in Figure .The Nyquist plots are shown in Fig 3(a ), Fig 3(b) i and 3(b) ii .The Bode plots are shown in Fig 4(a), 4(b) i. and 4(b) ii. The corrosion parameters such as charge transfer resistance (Rt), double layer capacitance value (Cdl) derived from Nyquist and Bode plots are given in Table 4. When aluminium is immersed in an aqueous solution at pH 10, the charge transfer resistance Rt is 1.955 Ohm cm2, the double layer capacitance Cdl is 5.950 x 10-8 F/cm2 . When the formulation consisting of GA, MA and Zn2+ is added, the Rt, value increases and Cdl value decreases. This confirms that a protective film is formed on the metal surface. This decreases the corrosion rate of aluminium and increases the inhibition efficiency. 3.5 Analysis of Fluorescence spectra Fluorescence spectra has been used to confirm the formation protective film and the metal surface.(ref). Al3+ /Al complex solution was prepared by mixing aluminum sulphate and glutaric acid solution. This complex was excited at 300nm.The emission spectrum is shown in Fig 6 (a). A peak appears at 424.0 nm.The Aluminium metal specimen was immersed in aqueous solution containing 250ppm of adipic acid and 50ppm of Zn2+ .A protective film was formed on

metal

surface was consist .This film was excited at 300nm.A peak appears at

426.5nm. This peak very closely resembles that of Al3+ /Al complex. Hence is confirmed that the protective film formed on the metal surface was consist Al3+ /Al complex. The decreases intensity of the spectrum may be due to the facts that the complex is in the solid state where the electronic transition is restricted. This analysis of Fluorescence spectra study leads to the conclusion that protective film consist of Al3+ /Al complex. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 Fluorescence spectra has been used to confirm the formation protective film and the metal surface.(ref). Al3+ /Al complex solution was prepared by mixing aluminum sulphate and malonicacid solution. This complex was excited at 300nm.The emission spectrum is shown in Fig 6 (b). A peak appears at 425.0 nm.The Aluminium metal specimen was immersed in aqueous solution containing 250ppm of adipic acid and 50ppm of Zn2+ .A protective film was formed on

metal

surface was consist .This film was excited at 300nm.A peak appears at

426.5nm. This peak very closely resembles that of Al3+ /Al complex. Hence is confirmed that the protective film formed on the metal surface was consist Al3+ /Al complex. The decreases intensity of the spectrum may be due to the facts that the complex is in the solid state where the electronic transition is restricted. This analysis of Fluorescence spectra study leads to the conclusion that protective film consist of Al3+ /Al complex. 3.6Analysis of FTIR spectra FTIR spectra have been used to confirm the presence of protective film formed on metal surface [41]. FTIR spectra of pure glutaric acid (kBr) is shown in Figure 7 (a) . The peak appears at 1629.3cm-1 is due to the CO stretching frequency of the carbonyl groups. The OH stretching frequency of the carboxyl groups appears at 3431.9 cm-1.The aliphatic CH stretching frequency appears at 2855.2 cm-1h. Thus glutaric acid is confirmed by FTIR spectra. The FTIR spectra (kBr) of the protective film formed on the metal surface after immersion in the solution containing 250ppm of glutaric acid and 50ppm of Zn2+ is shown in Figure7 (b). Its observed that CO stretching

frequency has shifted from

1629.3cm-1 to1641.4cm-1.The OH stretching

frequency has shifted from 3431.9 cm-1to 3450.8 cm-1.This suggest that glutaric acid has coordinate with Al3+ on the metal surface through carbonyl oxygen atom of carboxyl groups. The peak at 673.9 is due to a Metal –Oxygen bond[M-O].The peak at 3450.8 cm-1 is due to OH groups. This indicates that there is possibility of zinc hydroxide and /or aluminum hydroxide on metal surface. Thus if analysis of FTIR spectra leads to the conclusion that the protective film consist of Al3+ /Al complex and zinc hydroxide. There is also possibility of formation of aluminium hydroxide on the metal surface. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 3.7 Analysis of SEM and EDAX spectra The SEM and EDAX spectra have been used to investigate the smooth of the surface of the protective film formed on the metal surface during corrosion inhibition study. The SEM image of polished metal is shown in Figure 9(a).The EDAX spectra is also shown in Figure 10(b). The weight percentage of aluminium is given in Table 5.The SEM image of aluminium metal immersed in an aqueous at the corrosive medium (aqueous solution at PH -10 ) is shown in Figure 9 (b). The EDAX spectra is also shown in Figure 10(b).The weight percentage of various elements is given in Table 6 and 8.The SEM image of protective film formed on the metal surface after immersed in pH -10 of the solution containing 250ppm of glutaric and malonic acid and 50ppm of Zn2+ is shown in Figure 9 (c). The EDAX spectra is also shown in Figure 10(c). The weight percentage of various elements is given in Table 7and 9 It is absorbed that SEM image of polished metal is smooth. When the metal is placed in the corrosive medium the surface become smooth. The image also indicated present of crystal of Al3+ /Al complex formed on the metal surface. The EDAX spectra reviewing the presence of aluminium for polished metal weight percentage OF aluminium 1.65% for the metal immersed in corrosive medium the weight percentage of aluminum is higher (3.5%) .This is due to the facts the corrosive medium has contract aluminium and exposable more aluminium. In the dealing the weight percentage of aluminium for the inhibitor is less than that for the corrosive medium system. This is due to the fact glutaric and malonic acid and Zinc hydroxide have been absorbed on the metal surface and prevented corrosion. 3.8 Analysis of Atomic Force Microscopy Atomic Force microscopy is a powerful technique for the gathering of roughness statistics from a variety of surfaces [42]. AFM is becoming an accepted method of roughness investigation [43, 44, 45].The AFM images of polished metal, surface immersed in corrosive medium (an aqueous solution pH 10) and that of film formed on metal surface after immersion in the inhibitor solution containing 250 ppm of GA and 50 ppm of Zn2+ are shown in Figure 11.The RMS roughness (Rq), average roughness (Ra) and peak valley (P-V) height are given in Table.8. For polished metal surface, the RMS roughness (Rq) is 27.95nm.When the metal is immersed in the corrosive Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 medium, corrosion

products are produced and hence the RMS roughness is very high

(168.8nm).Interestingly, in the inhibitor system, the roughness is less (66.07nm) than that for corrosive medium; but higher than that for the polished metal. This indicates that a protective film is formed on the metal surface whose thickness is of the order of 78.7nm.This is due to the formation of self assembling monolayers of glutaricacid on the metal surface on the anodic sites of the metal surface. The AFM images of polished metal, surface immersed in corrosive medium (an aqueous solution pH 10) and that of film formed on metal surface after immersion in the inhibitor solution containing 250 ppm of MA and 50 ppm of Zn2+ are shown in Figure 12.The RMS roughness (Rq), average roughness (Ra) and peak valley (P-V) height are given in Table.9. For polished metal surface, the RMS roughness (Rq) is 27.95nm.When the metal is immersed in the corrosive medium, corrosion

products are produced and hence the RMS roughness is very high

(168.8nm).Interestingly, in the inhibitor system, the roughness is less (32.29nm) than that for corrosive medium; but higher than that for the polished metal. This indicates that a protective film is formed on the metal surface whose thickness is of the order of 78.7nm.This is due to the formation of self assembling mono layers of malonic acid on the metal surface on the anodic site of the metal surface. 3.9 Analysis of HOMO and LUMO Based on HOMO and LUMO calculation zinc malonic acid complex is more stable than Zinc glutaric acid complex. When Aluminium is immersed in corrosive medium, these complexes diffuse towards the metal surfaces. In the presence of Aluminium ion, the Zinc inhibitor complex must be broken and the inhibitor must compile with Al3+. It has been prove that based on HOMO and LUMO calculation Zinc malonic acid complex is more stable and Zinc glutaric acid complex is a less stable. So in presence of Al3+ Zinc glutaric acid complex is more easily broken, so easily compiles with Al3+ abut in the case of Zinc malonic acid complex (which is more stable according HOMO and LUMO calculation Table 10). Zinc malonic acid is less readily broken ,so the amount of glutaric acid least in the presence of Al3+is high. Hence more Al3+glutaric acid complex is formed on the metal surface and less amount of Al3+malonic acid complex is formed. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 Moreover According to Bayer Strain theory aluminum glutaric acid is more stable than aluminum malonic acid complex because the farmer is six membered ring whereas the later is four membered ring in Figure15 (a) and 15 (b) It is observed that in the present study consisting of two inhibitor system. The corrosion inhibition efficiency is explained .Bascially more on Bayer Strain theory which explained the stability of strainless complexes. Decrease in energy gap ΔE and corrosion inhibition efficiency (IE)

It is observed from Table that malonic acid has lower ΔE value(6.6244eV) than glutaric acid (6.9158 eV). It implies that malonic acid has better corrosion inhibition than glutaric acid due to the following reasons: ‫ ٭‬Malonic acid is more polarisable and higher reactivity (than glutaric acid) ‫٭‬Malonic acid has low kinetic stability, soft molecule and strongly interact with metal surface. ‫٭‬Energy difference is a lower values so it will render good inhibition efficiency, because the energy to remove an electron from the last occupied orbital will be low. When these complex metal surface Zinc oxalate is readily broken but Zinc glutaric acid complex is easily formed that of aluminium malonic acid complex.According to Bayer Strain theory the glutaric acid Aluminium complex seven membered ring is a strain less complex.This strain is very less and that compare oxalate complex. So this more aluminiu, glutraic complex is more stable than malonic acid Correlation between corrosion inhibiton efficiency and absolute hardness and Softness

Its observed that malonic acid has lower hardness value (3.3122ev) and higher softness value (0.3019ev) than glutaric acid (3,4579ev and 0.2891ev).A molecule with low hardness value and higher softness value has better inhibition efficiency.The softer a molecule better the inhibition efficiency. The soft molecule malonic acid has low energy gap (6.6244ev) and the hard molecule glutaric acid has higher energy gap(6.9158ev). The correlation between softness of the molecule and corrosion inhibition efficiency is explained as follow. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 Absolute hardness and softness are the essential parameters to measure the molecular stability and reactivity. Its well known that the chemical hardness fundamentally signifies the resistance towards the deformation or polarization of the study. 4.Conclusion ‫ ٭‬The present study leads to the following conclusion ‫ ٭‬The Formulation consisting of 250ppm of adipic acid and 50ppm of Zn2+ offers 95% inhibition efficiency of aluminium immersed in an aqueous solution at pH 10; ‫ ٭‬Polarization study reveals that the composition of 250 ppm AA and 50 ppm Zn2+ function as the anodic inhibitor; ‫ ٭‬AC impedance spectra reveals that a protective film formed on the metal surface; ‫ ٭‬FTIR spectra reveal that the protective film consists of Al3+ /Al complex and Zn(OH)2 ‫ ٭‬SEM and EDX confirm the presence of a protective film on the metal surface. ‫ ٭‬HOMO and LUMO stability of the strainless complex. 5. Acknowledgement The authors are thankful to their respective management for their help and encouragement. 6. References [1]. R. Rosliza, W.B. Wan Nik, H.B. Senin, The effect of inhibitor on the corrosion of aluminum alloys in acidic solutionsMater.Chem. Phys.vol.107, pp. 281288, 2008. [2]. A. Aytac,Cu(II), Co(II) and Ni(II) complexes of –Br and –OCH2CH3substituted Schiff bases as corrosion inhibitors for aluminum in acidic media”J.Mater. Sci., vol. 45, pp. 6812-6818, 2010 [3]. I.B. Obot, N.O. Obi-Egbedi, Fluconazole as an inhibitor for aluminium corrosion in 0.1 M HCl”Colloids Surf A: Physicochem. Eng. Asp., vol.330, pp. 207-212, 2008. [4]. Berthier P. Today in Science History. 2007 Aug 11. [5]. Deville HES-C. De l'aluminium, ses propriétés, sa fabrication. Paris; 1859. [6]. Cochran JF, Mapother DE. Superconducting transition in aluminum. PhysRev. 1958;111:132-142. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 [7]. Aluminium. Encyclopædia Britannica. [8]. Hetherington LE, Brown TJ, Benham AJ, Lusty PAJ, Idoine NE. Worldmineral production 2001-2005. British Geological Survey; 2007. [9]. Rising Chinese Costs to Support Aluminum Prices. Bloomberg News. 2009Nov 23. [10]. Millberg LS. Aluminum Foil. How Products are Made. 2007 Aug 11. [11]. Reciclado del aluminio. Confemetal.es ASERAL. [12]. Umoren,S.A., (2009). “Polymers as corrosion inhibitors for metals in different me dia,”The Open Corros. J. 2, 175-188. [13] Oguzie, E.E., (2007). “Corrosion inhibition of aluminium in acidic and alkaline media by Sansevieria trifasciata extract,” Corros. Sci. 49, 1527–1539 [14]. Sorkhabi,H. A., Ghasemi, Z., and Seifzadeh, D. (2005). “The inhibition effect of some amino acids towards the corrosion of aluminium in 1 M HCl + 1 M H2SO4 solution, ”Appl. Suf. Sci. 247, 408-418. [15]. Polmear IJ. Light alloys: metallurgy of the light metals. Arnold; 1995. [16]R.Epshiba,A.PeterPascalRegis and S.Rajendran,“Inhibition Of Corrosion Of Carbon Steel In A Well

Water By Sodium Molybdate – Zn2+ System”,Int. J. Nano Corr. Sci. Engg.

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N. Kavitha and P. Manjula, “Corrosion Inhibition of Water Hyacinth Leaves, Zn2+

and TSC on Mild Steel Inneutralaqueousmedium”,IntJ.NanoCorr.Sci.Engg1(1)2014)

31-

38. [18] R.Nagalakshmi , L.Nagarajan ,R.Joseph Rathish , S.Santhana Prabha ,N.Vijaya , J.Jeyasundari and S.Rajendran, “Corrosion Resistance Of SS316l In Artificial Urine In Presence Of D-Glucose”, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 39-49. [19] J. Angelin Thangakani, S. Rajendran ,J. Sathiabama , R M Joany , R Joseph Rathis , S. SanthanaPrabha Inhibition Of Corrosion Of Carbon Steel In Aqueous Solution Containing Low Chloride Ion By Glycine – Zn2+ System”, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 50-62.



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Corrosion Inhibition by self assembling monolayers of glutaric and malonic acid P.Satyabama1*, S.Rajendran2 and S.Senthil Kumaran3 [20] A. Nithya , P.Shanthy, N.Vijaya, R.Joseph Rathish, S.Santhana Prabha, RM Joany and S.Rajendran, “Inhibition Of Corrosion Of Aluminium By An Aqueous Extract Of Beetroot (Betanin)”,Int. J. Nano Corr. Sci. Engg. 2(1) (2015)1-11. [21] T.Gowrani, P.Manjula, Nirmala Baby, K.N.Manonmani, R.Sudha, T.Vennila,“Thermodyna mical Analysis Of MBTA On The Corrosion Inhibition Of Brass In 3% NaCl Medium”,Int.J. Nano. Corr. Sci. Engg. 2(1) (2015)12-21. [22] K.Namita, K. Johar, Bhrara, R.Epshiba and G. Singh, “Effect Of Polyethoxyethylene N, N, N` 1, 3 Diamino Propane On The Corrosion Of Mild Steel In Acidic Solutions”,Int. J.Nano Corr. Sci. Engg.2(1) (2015)22-31. [23]A.Christy Catherine Mary,S.Rajendran,Hameed Al-Hashem, R.Joseph Rathish, Jeyasundari, T.Umasankareswari, “Corrosion Resistance Of Mild Steel In Simulated

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Presence Of Sodium PotassiumTartrate”,IntJ.NanoCorr.Sci.Engg. 2(1) (2015) 42-50. [24]P.Nithya Devi, J.Sathiyabama , Prabha,Influence of

S.Rajendran , R Joseph Rathish and S Santhana

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Simulated Concrete Pore Solution, Int J Nano Corr Sci and Engg 2(3) (2015) 1-13. [25] V.Johnsirani , S.Rajendran , A.Christy Catherine Mary ,

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T.Umasankareswari and J Jeyasundari,Corrosion inhibition by dyes from plants, Int J Nano Corr Sci and Engg 2(3)(2015) 22-28. [26]A.Christy Catherine Mary, S.Rajendran,R Joseph Rathish, A

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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama

Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama 1,S.Rajendran2 1.University College of Engineering –Dindigul, Dindigul, Dindigul,Tamilnadu,India Email :[email protected] 2. Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India, Email :[email protected]

Abstract The inhibition nhibition efficiency of oxalic acid in controlling corrosion of Aluminium in an aqueous solution at pH 10, in the absence and presence of Zn2+ has been evaluated by weight loss method. The formulation consisti consisting of 250 ppm of oxalic acid and 50 ppm of Zn2+ has 95% corrosion inhibition efficiency. A synergistic synergist effect exits between oxalic acid and Zn2+. The mechanistic aspects of corrosion inhibition inhi have been evaluated by polarization study and AC impedance spectra.. In the presence of inhibitor, linear polarization resistance increa increases;corrosion current decreases; charge transfer resistance value increases; impedance value increases and double large capacitance decreases . The protective film has been

analyzed

by UVand

Flouresence spectra. Keywords: Corrosion inhibition, Aluminium at pH10 pH10, oxalic acid, synergistic effect



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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama 1. Introduction Aluminum is one of the metals which used in different human activities and many of important applications, where it isthe second most abundant metal after iron, it has a low atomic mass and negative value of standard electron potential,aluminum potentially attracts as an anodic material for power sources with high energy density. It is used in construction, packing and transportation because of its strength and electrical conductivity. Aluminum is used inelectronics due to it is super purity [1]Aluminum and its alloys have a remarkable economic and attractive materials for engineeringapplications owing to its low cost, light weight, high thermal and electrical conductivity. The interestof the materials arises from their importance in recent civilization. Inhibition of metal corrosion byorganic compounds is a result of adsorption of organic molecules or ions at the metal surface forming aprotective layer. This layer reduces or prevents corrosion of the metal. The extent of adsorptiondepends on the nature of the metal, the metal surface condition, the mode of adsorption, the chemicalstructure of the inhibitor, and the type of corrosion media[2]. To prevent the attack of acid, it is veryimportant to add a corrosion inhibitor to decrease the rate of Al dissolution in such solutions. Thus,many studies concerning the inhibition of Al corrosion using organic substances are conducted inacidic and basic solutions [3-7].

The present work is undertaken i.To evaluate the inhibition efficiency of oxalic acid in controlling corrosion of aluminium immersed in an aqueous solution at pH 10, in the absence and presence of Zn2+ using the mass loss method ii.To study the mechanistic aspects of corrosion inhibition by potentiodynamic polarization and AC impedance spectra iii.To analyse the protective film by UV-visible absorption spectroscopy and Fluorescence spectra 1. 2. METHODS AND MATERIALS 2. 2.1. Preparation of specimens Commercial aluminium specimens of dimensions 1.0 x 4.0 x 0.2cm, containing 95% pure aluminium were polished to mirror finish, degreased with trichloroethylene, and used for the Mass-loss method .



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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama 3. 2.2. Weight loss method Three aluminium specimens were immersed iin 100mL of the solution at pH 10 and various concentrations of the inhibitor in the absence and presence of Zn2+ for a period of 1 day. The weight of the specimen before and after immersion was determined using shimadzu balance AY62.Inhibition efficiency (IE) was calculated from the relationship. IE = 100 [1-W2/W1)] W2/W1)] % Where W1 and W2 are the corrosion rates in the absence and presence of the inhibitor, respectively. 4. 2.3. UV – visble spectrum A spectrophotometer can be either single beam or double beam.. In a single beam instrument (such as the Spectronic 20), ), all of the light passes through the sample cell.

must be measured

by removing the sample. This was the earliest design and is still in common use in both teaching and industrial labs. In a double-beam double beam instrument, the light is split into two beams before it reaches the sample. One beam is used as the reference; reference; the other beam passes through the sample. The reference beam intensity is taken as 100% Transmission (or 0 Absorbance), and the measurement displayed is the ratio of the two beam intensities. Some double-beam double beam instruments have two detectors (photodiodes), (photodiodes), and the sample and reference beam are measured at the same time. In other instruments, the two beams pass through a beam chopper,, which blocks one beam at a time. The detector or alternates between measuring the sample beam and the reference beam in synchronism with the chopper. There may also be one or more dark intervals in the chopper cycle. In this case, the measured beam intensities may be corrected by subtracting the intensity inten measured in the dark interval before the ratio is taken. 5. 2.4. Fluroscence spectra In fluorescence spectroscopy, the species is first excited, by absorbing a photon photon, from its ground electronic state to one of the various vibrational states in the excited electronic state. Collisions with other molecules cause the excited molecule to lose vibrational energy until it reaches the lowest vibrational state of the excited electronic state. In a typical fluorescence (emission) measurement, the excitation wavelength is fixed and the detection wavelength varies, while in a Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama fluorescence excitation measurement the detection wavelength is fixed and the excitation wavelength is varied across a region of interest.Fluorescence spectroscopy is used in, among others, biochemical, medical, and chemical research fields for analyzing organic compounds. There has also been a report of its use in differentiating malignant skin tumors from begin.. 6. 3. RESULTS AND DISCUSSION 7. 3.1. Analysis of result of weight loss method The corrosion rate of aluminium in an aqueous solution at pH 10 (dil NaOH) in the absence and presence of inhibitors obtained by weight loss method are given in Table 1. The inhibition efficiency are also given in this table. Table -1 Corrosion rates of Aluminium in an aqueous solution at pH 10 (dil NaOH),in the absence and presence of inhibitor system and the inhibition efficiencies (IE) obtained from weight loss method. Inhibitor system : oxalic acid (OA)and Zn2+ oxalic acid ppm

Zn2+ system ppm

Corrosion rate mdd

Inhibition %

0 50 100 150 200 250 Table -2

0 0 0 0 0 0

23.48

-70 72 74 75 78

efficiency

Corrosion rates of Aluminium in an aqueous solution at pH 10 (dil NaOH),in the absence and presence of inhibitor system and the inhibition efficiencies (IE) obtained from weight loss method. Inhibitor system : oxalic acid (OA) and Zn2+ Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama oxalic acid ppm

Zn2+system Ppm

Corrosion rate Mdd

Inhibition %

0 50 100 150 200 250 0

50 50 50 50 50 50 50

23.48 2.58 2.11 1.87 1.40 1.17 19.25

-89 91 92 94 95 18

efficiency

8. 3.2. Analysis of UV –visible absorption spectra UV-visible absorption spectrum of an aqueous solution containing oxalic acid and Al3+ (Aluminium Sulphate) is shown in Fig.1 A peak appears at 420nm .Is indicate that a complexes from between Al3+ and oxalic acid Fig.1

Fig.1 UV – visible absorption spectrum of an solution containing Oxalic acid and Al3+

9. 3.3. Analysis of Fluroscence spectra The Fluroscence spectrum (λexcitation = 300nm) Fluroscence spectrum of an aqueous solution containing Al3+ and adipicacid (Al3+-Oxalic acid ) is shown in Figure 2a. Apeak appears at 392.5nm. The fluroscence spectrum of (λexcitation = 300nm) protective film formed on aluminium metal surface after immersion in the solution containing 250ppm of Oxalic acid and 50ppm Zn2+ solution after for 1 day is shown in figure 2b. A peak appears at 425.0nm.The peak matches which that of aluminium Oxalic acid complex. Hence it is confirm that the protective film formed on the metal surface is Aluminium and Oxalic acid complex ion



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Fig.2a Fluroscence spectrum of an solution containing Oxalic acid and Al3+ Fig.2b Fluroscence spectrum of an solution containing250ppm Oxalic acid and 50ppm Zn2+

10. 3.4 Analysis of SEM and EDAX spectra The SEM and EDAX spectra have been used to investigate the smooth of the surface of the protective film formed on the metal surface during corrosion inhibition study. The SEM image of polished metal is shown in Figure 3(a).The EDAX spectra is also shown in Figure 4(b). The weight percentage of aluminium is given in Table 3.The SEM image of aluminium metal immersed in an aqueous at the corrosive medium (aqueous solution at PH -10 ) is shown in Figure 3 (b). The EDAX spectra is also shown in Figure 4(b).The weight percentage of various elements is given in Table 5 and 6.The SEM image of protective film formed on the metal surface after immersed in pH -10 of the solution containing 250ppm of oxalic acid and 50ppm of Zn2+ is shown in Figure 3 (c). The EDAX spectra is also shown in Figure 4(c). The weight percentage of various elements is given in Table 7and 9. It is absorbed that SEM image of polished metal is smooth. When the metal is placed in the corrosive medium the surface become smooth. The image also indicated present of crystal of Al3+ /Al complex formed on the metal surface. The EDAX spectra reviewing the presence of aluminium for polished metal weight percentage OF aluminium 1.65% for the metal immersed in corrosive medium the weight percentage of aluminum is higher (3.5%) .This is due to the facts the corrosive medium has contract aluminium and exposable more aluminium. In the dealing

the weight percentage of aluminium for the inhibitor is less than that for the corrosive

medium system. This is due to the fact adipic acid and Zinc hydroxide have been absorbed on the metal surface and prevented corrosion. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Table-3 Data derived from SEM image polished metal El

AN

Series

Al O C

13 6 8

K-series K-series K-series

unn. [wt.% 85.33 8.51 2.15

C norm. [wt.%] 88.89 8.86 2.24

C Atom. C Error [wt.%] 78.95 17.68 3.36

(1Sigma) [wt.%] 4.12 3.11 0.79

Table-4 Data derived from SEM image Metal in corrosive medium (OA) El

AN

Series

Al C Fe O Si

13 6 26 8 14

K-series K-series K-series K-series K-series

(c) polished metal

unn. [wt.% 77.17 14.86 11.41 3.21 1.20

C norm. [wt.%] 71.52 13.77 10.57 2.97 1.16

C Atom. [wt.%] 62.91 27.20 4.49 4.41 0.98

C Error

(1Sigma) [wt.%] 3.80 6.73 0.55 1.60 0.15

(d) Metal in corrosive medium c) Metal in presence of inhibitors Fig 3 : SEM images of the surface of Aluminium metal (OA)

30

cps/eV

30

cps/eV

cps/eV

25

35

25 30

20 20 25

15

15

20 C

O

Fe C O

Al

Al Si

Fe C O

Fe

15

Al Si

Fe

10

10 10

5

5 5

0

0

0 1

2

3 keV

4

(e) polished metal

5

6

1

2

3

4

5 keV

6

7

8

9

(f) Metal in corrosive medium

10

1

2

3

4

5 keV

6

7

8

9

10

c) Metal in presence of inhibitors

Fig 4: EDX images of the surface of Aluminium metal (OA)



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Self Assembling monolayers of nanofilms by oxalic acid P.Satyabama 11. 4. Conclusion The present study lead to the following conclusions Inhibition efficiency of Oxalic acid in controlling corrosion of aluminium in distillate water in the absence and presence of Zn2+ has been evaluated by weight loss method UV –visible spectra reveal that the protective film consists of Al3+ and oxalic acid complex 12. References [1] R. Rosliza, W.B. Wan Nik, H.B. Senin, “The effect of inhibitor on the corrosion of aluminum alloys in acidic solutions”, Mater. Chem. Phys., vol. 107, pp. 281-288, 2008. [2]. A.A. Mazhar, W.A. Badaway and M.M. Abou-Romia, Surf. Coat. Techol., 29 (1986)335 [3]. M. Stern and A.I.J. Geary, J. Electrochem. Soc., 104(1957)56 [4]. A.K.Maayta and N.A.F. Al-Rawashdeh , Corros Sci., 46(2004)1129 [5]. E.E.Ebenso ,P.C.Okafor and U.J.Ekpe, Anti-Corrosion Methods and Materials, 37(2003)381 [6]. G.Bereket, A.Pinarbasi and C.Ogretir, Anti-Corrosion Methods and Materials, 51 (2004) 282 [7]. A.S.Fouda, M.N.Moussa, F.I.Taha and A.I.Elneanaa, Corros.Sci., 26(1986)719.




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Corrosion Inhibition of Aluminium in an aqueous solution at pH 10 by adipic acid - Zn2+ system P.Satyabama

Corrosion Inhibition of Aluminium in an aqueous solution at pH 10 by adipic acid - Zn2+ system P.Satyabama 1,S.Rajendran2 1.

University College of Engineering –Dindigul, Dindigul, Dindigul,Tamilnadu,India Email :[email protected]

2.

Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India, Email :[email protected]

Abstract The inhibition nhibition efficiency of adipic acid in controlling corrosion of Aluminium in an aqueous solution at pH 10, in the absence and presence of Zn2+ has been evaluated by weight loss method. The formulation consisti consisting of 250 ppm of adipic acid and 50 ppm of Zn2+ has 95% corrosion inhibition efficiency. A synergistic synergist effect exits between adipic acid and Zn2+. The mechanistic aspects of corrosion inhibition have been evaluated by polarization study and AC impedance spectra. In the presence of inhibitor , linear polarization

resistance

increases

;corrosion current decreases; charge transfer resistance value increases; impedance impeda value increases and double large capacitance decreases . The protective film has been analyzed by UVand Flouresence spectra. The stability and strain or strainless complex has been investigated by HOMO and LUMO study. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. (4)(2016) 359 - 375 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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Keywords: Corrosion inhibition, Aluminium at pH10, adipic acid, synergistic effect

1. Introduction Aluminum is one of the metals which used in different human activities and many of important applications, where it is the second most abundant metal after iron, it has a low atomic mass and negative value of standard electron potential, aluminium potentially attracts as an anodic material for power sources with high energy density. It is used in construction, packing and transportation because of its strength and electrical conductivity. Aluminium is used in electronics due to it is super purity [1]. Although Al has an adhesive protective passivating oxide film, but this film hasan amphoteric susceptibility, and consequently the metal dissolves readily in acidic and basic solutions concentrated above and below pH 4-9 [2, 3]. Aluminium and its alloys have a remarkable economic and attractive materials for engineering applications owing to its low cost, light weight, high thermal and electrical conductivity. The interest of the materials arises from their importance in recent civilization. Inhibition of metal corrosion by organic compounds is a result of adsorption of organic molecules or ions at the metal surface forming a protective layer. This layer reduces or prevents corrosion of the metal. The extent of adsorption depends on the nature of the metal, the metal surface condition, the mode of adsorption, the chemical structure of the inhibitor, and the type of corrosion media[4]. To prevent the attack of acid, it is very important to add a corrosion inhibitor to decrease the rate of Al dissolution in such solutions. Thus,many studies concerning the inhibition of Al corrosion using organic substances are conducted inacidic and basic solutions [5-9]. The present work is undertaken i.To evaluate the inhibition efficiency of adipic acid in controlling corrosion of aluminium immersed in an aqueous solution at pH 10, in the absence and presence of Zn2+ using the mass loss method ii.To study the mechanistic aspects of corrosion inhibition by potentiodynamic polarization and AC impedance spectra Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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iii.To analyse the protective film by UV-visible absorption spectroscopy and Fluorescence spectra 2. Methods And Materials 2.1. Preparation of specimens Commercial aluminium specimens of dimensions 1.0 x 4.0 x 0.2cm, containing 95% pure aluminium were polished to mirror finish, degreased with trichloroethylene, and used for the Mass-loss method . 2.2. Weight loss method Three aluminium specimens were immersed in 100mL of the solution at pH 10 and various concentrations of the inhibitor in the absence and presence of Zn2+ for a period of 1 day. The weight of the specimen before and after immersion was determined using shimadzu balance AY62.Inhibition efficiency (IE) was calculated from the relationship. IE = 100 [1-W2/W1)] % Where W1 and W2 are the corrosion rates in the absence and presence of the inhibitor, respectively. 2.3. Potentiodynamic polarization study Polarization study was carried out in a CHI electrochemical work station impedance analyzer model 660A. A three electrode cell assembly was used. The working electrode was Aluminium, A saturated calomel electrode (SCE) was the reference electrode and platinium was the counter electrode. The corrosion parameters such as linear polarization Resistance. (LPR), corrosion potential, Ecorr, corrosion current, Icorr, and Tafel slopes (ba and bc) were measured. 2.4. HOMO and LUMO study HOMO and LUMO are the highest occupied molecular orbital

and

lowest unoccupied

molecular orbital, respectively. The energy difference between the HOMO and LUMO is termed the HOMO–LUMO gap. HOMO and LUMO are sometimes referred to as frontier orbitals in Frontier Molecular orbital Theory.

The difference in energy between these



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two frontier orbitals used to predict the strength and stability of transition metal complexes, as well as the colors they produce in solution 2.5.UV – visble spectrum A spectrophotometer can be either single beam or double beam.. In a single beam instrument (such as the Spectronic 20), ), all of the light passes through the sample cell.

must be measured

by removing the sample. This was the earliest design and is still in common use in both teaching and industrial labs. In a double-beam double beam instrument, the light is split into two beams before it reaches the sample. One beam is used as the reference; reference; the other beam passes through the sample. The reference beam intensity is taken as 100% Transmission (or 0 Absorbance), and the measurement displayed is the ratio of the two beam intensities. Some double-beam double beam instruments have two detectors (photodiodes), (photodiodes), and the sample and reference beam are measured at the same time. In other instruments, the two beams pass through a beam chopper,, which blocks one beam at a time. The detector or alternates between measuring the sample beam and the reference beam in synchronism with the chopper. There may also be one or more dark intervals in the chopper cycle. In this case, the measured beam intensities may be corrected by subtracting the intensity inten measured in the dark interval before the ratio is taken. 2.6. Fluroscence spectra In fluorescence spectroscopy, the species is first excited, by absorbing a photon photon, from its ground electronic state to one of the various vibrational states in the excited electronic state. Collisions with other molecules cause the excited molecule to lose vibrational energy until it reaches the lowest vibrational state of the excited electronic state. In a typical fluorescence (emission) measurement, the excitation wavelength is fixed and the detection wavelength varies, while in a fluorescence excitation measurement the detection wavelength is fixed and the excitation wavelength is varied across a regi region of interest.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. (4)(2016) 359 - 375 Int J Nano Corr Sci and Engg 3(4)(2016) Editors: Dr S Rajendran, A Christy Catherine Mary

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Fluorescence spectroscopy is used in, among others, biochemical, medical, and chemical research fields for analyzing organic compounds. There has also been a report of its use in differentiating malignant skin tumors from begin.. 3. Results And Discussion 3.1. Analysis of result of weight loss method The corrosion rate of aluminium in an aqueous solution at pH 10 (dil NaOH) in the absence and presence of inhibitors obtained by weight loss method are given in Table 1. The inhibition efficiency are also given in this table. Table -1 Corrosion rates of Aluminium in an aqueous solution at pH 10 (dil NaOH),in the absence and presence of inhibitor system and the inhibition efficiencies (IE) obtained from weight loss method. Inhibitor system : adipic acid (AA)and Zn2+ adipic acid ppm

Zn2+ system ppm

Corrosion rate mdd

Inhibition %

0 50 100 150 200 250

0 0 0 0 0 0

23.48 5.16 4.69 4.46 3.99 3.28

-78 80 81 83 86

efficiency

Table -2 Corrosion rates of Aluminium in an aqueous solution at pH 10 (dil NaOH),in the absence and presence of inhibitor system and the inhibition efficiencies (IE) obtained from weight loss method. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Corrosion Inhibition of Aluminium in an aqueous solution at pH 10 by adipic acid - Zn2+ system P.Satyabama 2+

Inhibitor system : adipic acid (AA) and Zn adipic acid ppm

Zn2+system Ppm

Corrosion rate Mdd

Inhibition %

0 50 100 150 200 250 0

50 50 50 50 50 50 50

23.48 2.58 2.11 1.87 1.40 1.17 19.25

-89 91 92 94 95 18

efficiency

3.2. Influence of Zn2+ on the inhibition efficiency of adipic acid(AA) The influence of Zn2+ on the IE of AA is given in Table 1. In the presence of Zn2+ ( 50ppm) excellent inhibitive property is shown by AA. A synergistic effect exists between AA and Zn2+ for example , 2mL of AA has 92% IE, 50ppm of Zn2+ has 13% IE. But their combination has 98%. 3.3. Influence of N-Cetyl N,N,N-trimethylammonium Zn2+ (50ppm) system. The influence of CTAB on the inhibition efficiency of AA(250ppm)-Zn2+ (50ppm) system is given in Table 2. It is interesting to find that the IE of the AA -Zn2+ system is not changed by the addition of CTAB. CTAB is a biocide .It can control the corrosion caused by inhibition efficiency. It is expected that this formulation will have excellent biocidal efficiency also. 3.4. Analysis of polarization curves Polarization study has been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process[10-22] .The potentiodynamic polarization curves of aluminium immersed in various solutions at pH 10 are shown in Fig1. The corrosion parameters such as corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr), tafel slopes (ba, bc) and linear polarization (LPR) are given in Table 3. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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When aluminium is immersed in an aqueous solution at pH 10, the corrosion potential is 506 mV vs SCE. When the inhibitors are added, (250ppm of AA and 50ppm of Zn2+) the corrosion potential shifted to anodic side (-416mV vs SCE). Further LPR value increases from 27355 to 400583 and corrosion current decreases from 20.62 10-7 A/cm2 to 1.14x 10-7 A/cm2. These results suggest that a protective film is formed on the metal surface .This protects the metal from corrosion. Table -3 Corrosion parameters of Aluminium immersed in an aqueous solution at pH 10 (dil NaOH),in the absence and presence of inhibitor system obtained from polarization study Inhibitor system : Adipic acid (AA)and Zn2+ AA ppm 0

Zn2+ ppm 0

Ecorr mV vs SCE -506

bc mV 314

ba mV 220

LPR Ohm cm2 27355

I corr A/cm2 20.62x10-7

250

50

-416

202

217

400583

1.14x10-7

Fig 1:Polarization curves of aluminium immersed in an aqueous solution at pH 10



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Fig 2:Polarization curves of aluminium immersed in an aqueous solution at pH 10in presence of AA 250ppm and Zn2+

3.5. Analysis of AC impedance spectra AC impedance spectra (electrochemical impedance spectra) have been used to confirm the formation of protective film on the metal surface . If a protective film is formed on the metal surface , charge transfer resistance (Rt) increases and double layer capacitance value (Cdl) decreases (10 -17).The AC impedence spectra of aluminium immersed in various solution are shown in figure 3 and 4. The AC impedence spectra such as charge transfer resistance (Rt), double layer capacitance value (Cdl) derived from Nyquist and Bode plots are given in Table 4. When aluminium is immersed in an aqueous solution at pH 10, the charge transfer resistance Rt is 2.036 ohm cm2., the double layer capacitance Cdl is 0.05x 10-4 F/cm2 . When the formulation consisting of AA and Zn2+ is added , the Rt, value increases and Cdl value decreases. This confirms that a protective film is formed on the metal surface. This decreases the corrosion rate of aluminium and increases the inhibition efficiency.



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Table -4 Corrosion parameters of Aluminium immersed in an aqueous solution at pH 10 (dil NaoH),in the absence and presence of inhibitor system obtained from AC impedance spectra Inhibiton system :Adipicacid (AA) and Zn2+ AA

Zn2+

Rt

Cdl

Bode plot

Ppm

ppm

ohm cm2

F/cm2

Impedance log(z/ohm)

0

0

85.67

5.836x10-8

2.036

250

50

2911

1.717x10-9

3.624

Fig 3:AC impedance spectra of aluminium immersed in an aqueous solution at pH 10 (Nyquistplot

)



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Fig 4:AC impedance spectra of aluminium immersed in an aqueous solution AA 250ppm + Zn2+ 50ppm at pH 10(Nyquist plot)

Fig 5:AC impedance spectra of aluminium immersed in an aqueous solution at pH 10 (Bode plot)



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Fig 6:AC impedance spectra of aluminium immersed in an aqueous solutionin presence of AA 250ppm+ at Zn2+ 50ppm pH 10 (Bode plot)

3.6. Analysis of UV –visible absorption spectra UV-visible absorption spectrum of an aqueous solution containing adipic acid and Al3+ (Aluminium Sulphate) is shown in Fig.7 A peak appears at 420nm .Is indicate that a complexes from between Al3+ and adipic acid Fig.7



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Corrosion Inhibition of Aluminium in an aqueous solution at pH 10 by adipic acid - Zn2+ system P.Satyabama Fig.7 UV – visible absorption spectrum of an solution containing Adipic acid and Al3+

3.7. Analysis of Fluroscence spectra The Fluroscence spectrum (λexcitation = 300nm) Fluroscence spectrum of an aqueous solution containing Al3+ and adipicacid (Al3+-Adipic acid ) is shown in Figure 8a.Apeak appears at 426.6nm. The fluroscence spectrum of (λexcitation = 300nm) protective film formed on aluminium metal surface after immersion in the solution containing 250ppm of adipic acid and 50ppm Zn2+ solution after for 1 day is shown in figure 8b. A peak appears at 420.5n.The peak matches which that of aluminium adipic acid complex. Hence it is confirm that the protective film formed onthe metal surface is Aluminium and adipic acid complex ion

Fig.8a Fluroscence spectrum of an solution containing Adipic acid and Al3+ Fig.8b Fluroscence spectrum of an solution containing250ppm Adipic acid and 50ppm Zn2+

3.8 Analysis of HOMO and LUMO Based on HOMO and LUMO calculation zinc adipic acid complex is more stable complex. When Aluminium is immersed in corrosive medium, these complexes diffuse towards the metal Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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surfaces. In the presence of Aluminium ion, the Zinc inhibitor complex must be broken and the inhibitor must compile with Al3+. It has been prove that based on HOMO and

LUMO

calculation Zinc adipic acid complex is more stable . So Zinc adipic acid is less readily broken ,so the amount of adipic acid least in the presence of Al3+is high. Hence less amount of Al3+adipic acid complex is formed. Moreover According to Bayer Strain theory aluminum adipic acid complex is four membered ring in Figure7 .

Figure-7 Structure of Adipic acid

It is observed that in the present study consisting of two inhibitor system. The corrosion inhibition efficiency is explained . Bascially more on Bayer Strain theory which explained the stability of strainless complexes. Table 10: Calculated quantum chemical parameters of the studied molecules Parameters

AA

EHOMO (eV) ELUMO (eV) ΔE = ELUMO − EHOMO (eV) I = -EHOMO (eV)( ionization potential) A = -ELUMO (eV) (electron affinity) χ (eV) (Absolute electro negativity) η (eV) (hardness) S (softness) ΔE back donation

-7.5152 -0.6076 6.9076 7.5152 0.6076 4.0614 3.4538 0.2895 0.8634



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Decrease in energy gap ΔE and corrosion inhibition efficiency (IE) It is observed from Table that adipic acid has lower ΔE value(6.9076eV) . It implies that adipic acid has better corrosion inhibition due to the following reasons: ‫ ٭‬Adipic acid is more polarisable and higher reactivity. ‫ ٭‬Adipic acid has low kinetic stability, soft molecule and strongly interact with metal surface. ‫ ٭‬Energy difference is a lower values so it will render good inhibition efficiency, because the energy to remove an electron from the last occupied orbital will be low.

Figure -8 Energy difference between EHOMO AND ELUMO of Adipic acid

Correlation between corrosion inhibiton efficiency and absolute hardness and Softness

Its observed that Adipic acid has lower hardness value (3.4538ev) .A molecule with low hardness value and higher softness value has better inhibition efficiency.The softer a molecule better the inhibition efficiency. The soft molecule malonic acid has low energy gap (6.9076ev) . The correlation between softness of the molecule and corrosion inhibition efficiency is explained as follow Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Absolute hardness and softness are the essential parameters to measure the molecular stability and reactivity. Its well known that the chemical hardness fundamentally signifies the resistance towards the deformation or polarization of the study. 4. Conclusion The present study lead to the following conclusions Inhibition efficiency of Adipic acid in controlling corrosion of aluminium in distilluted water in the absence and presence of Zn2+ has been evaluated by weight loss method UV –visible spectra reveal that the protective film consists of Al3+ and adipic acid complex References [1]. R. Rosliza, W.B. Wan Nik, H.B. Senin, “The effect of inhibitor on the corrosion of aluminum alloys in acidic solutions”, Mater. Chem. Phys., vol. 107, pp. 281-288, 2008. [2]. A. Aytac, “Cu(II), Co(II) and Ni(II) complexes of –Br and –OCH2CH3 substituted Schiff bases as corrosion inhibitors for aluminum in acidic media”, J. Mater. Sci., vol. 45, pp. 68126818, 2010. [3]. I.B. Obot, N.O. Obi-Egbedi, “Fluconazole as an inhibitor for aluminium corrosion in 0.1 M HCl” Colloids Surf A: Physicochem. Eng. Asp., vol. 330, pp. 207-212, 2008. [4]. A.A. Mazhar, W.A. Badaway and M.M. Abou-Romia, Surf. Coat. Techol., 29 (1986)335 [5]. M. Stern and A.I.J. Geary, J. Electrochem. Soc., 104(1957)56 [6]. A.K.Maayta and N.A.F. Al-Rawashdeh , Corros Sci., 46(2004)1129 [7]. E.E.Ebenso ,P.C.Okafor and U.J.Ekpe, Anti-Corrosion Methods and Materials, 37(2003)381 [8]. G.Bereket, A.Pinarbasi and C.Ogretir, Anti-Corrosion Methods and Materials, 51 (2004) 282 [9] A.S.Fouda, M.N.Moussa, F.I.Taha and A.I.Elneanaa, Corros.Sci., 26(1986)719 [10] R.Epshiba,A.PeterPascalRegis and S.Rajendran,“Inhibition Of Corrosion Of Carbon Steel In A Well Water By Sodium Molybdate – Zn2+ System”,Int. J. Nano Corr. Sci. Engg. (1) (2014) 111. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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[11] N. Kavitha and P. Manjula, “Corrosion Inhibition of Water Hyacinth Leaves, Zn2+ and TSC on Mild Steel Inneutralaqueousmedium”,IntJ.NanoCorr.Sci.Engg1(1)2014)

31-38.

[12] R.Nagalakshmi , L.Nagarajan ,R.Joseph Rathish , S.Santhana Prabha ,N.Vijaya , J.Jeyasundari and S.Rajendran, “Corrosion Resistance Of SS316l In Artificial Urine In Presence Of D-Glucose”, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 39-49. [13] J. Angelin Thangakani, S. Rajendran ,J. Sathiabama , R M Joany , R Joseph Rathis , S. SanthanaPrabha Inhibition Of Corrosion Of Carbon Steel In Aqueous Solution Containing Low Chloride Ion By Glycine – Zn2+ System”, Int. J. Nano. Corr. Sci. Engg. 1(1) (2014) 50-62. [14] A. Nithya , P.Shanthy, N.Vijaya, R.Joseph Rathish, S.Santhana Prabha, RM Joany and S.Rajendran, “Inhibition Of Corrosion Of Aluminium By An Aqueous Extract Of Beetroot (Betanin)”,Int. J. Nano Corr. Sci. Engg. 2(1) (2015)1-11. [15] T.Gowrani, P.Manjula, Nirmala Baby, K.N.Manonmani, R.Sudha, T.Vennila,“Thermodyna mical Analysis Of MBTA On The Corrosion Inhibition Of Brass In 3% NaCl Medium”,Int.J. Nano. Corr. Sci. Engg. 2(1) (2015)12-21. [16] K.Namita, K. Johar, Bhrara, R.Epshiba and G. Singh, “Effect Of Polyethoxyethylene N, N, N` 1, 3 Diamino Propane On The Corrosion Of Mild Steel In Acidic Solutions”,Int. J.Nano Corr. Sci. Engg.2(1) (2015)22-31. [17]A.Christy Catherine Mary,S.Rajendran,Hameed Al-Hashem,R.Joseph Rathish , Jeyasundari R.Joseph Rathish, T.Umasankareswari, Simulated

Produced

“Corrosion

Water

In

Resistance

Of

Presence

Mild

Of

Steel

In

Sodium

PotassiumTartrate”,IntJ.NanoCorr.Sci.Engg. 2(1) (2015) 42-50. [18]P.Nithya Devi, J.Sathiyabama , Prabha,Influence of

S.Rajendran , R Joseph Rathish and S Santhana

citric acid-Zn2+ System on Inhibition of Corrosion of Mild Steel in

Simulated Concrete Pore Solution, Int J Nano Corr Sci and Engg 2(3) (2015) 1-13. [19] V.Johnsirani , S.Rajendran , A.Christy Catherine Mary ,

R.Joseph Rathish,

T.Umasankareswari and J Jeyasundari,Corrosion inhibition by dyes from plants, Int J Nano Corr Sci and Engg 2(3)(2015) 22-28. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


374


[20]A.Christy Catherine Mary, S.Rajendran,R Joseph Rathish, A


Inhibition by oxyanions, Int J Nano Corr Sci and Engg 2(3) (2015) 46-59. [21] A.Sahaya Raja, S.Rajendran, J.Sathiyabama, V.Prathipa, S.Anuradha, A. Krishnaveni and J Jeyasundari Synergism And Antagonism In Carbon Steel Corrosion Inhibition By Aminoacetic Acid (Glycine), Int J Nano Corr Sci and Engg 2(2) (2015) 31-39. [22] P.Shanthy, S.Rajendran, R.M.Joany T.Umasankareswari and M.Pandiarajan Influence Of ABiocide On The Corrosion Inhibition Efficiency Of Aspartic Acid- Zn2+System”,Int J Nano Corr Sci and Engg 2(2) (2015) 40-50.




375

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 5 1-(4-aryl aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 5 hydroxybenzaldehyde 11(4-aryl aryl-1, 3-thiazol-2yl)-hydrazones S. R. jayapradhaa & S. Muthusubramanianb aDepartment of Chemistry, Government Arts College for Women, Nilakottai – 624 208. bDepartment of Organic Chemistry, School of Chemistry, Madurai Kamaraj University Madurai -625021 Keywords: 2-methoxy/hydroxy methoxy/hydroxy-5-aryl aryl substituted benzaldehyde, thiazoles.

1. INTRODUTION Thiazole is a heterocyclic system featuring both nitrogen atom and sulfur atom as part of the aromatic five-membered membered ring. The thiazole ring system is useful structural motif possessing numerous biological activities1 along with many other applications and hence thiazole hiazole derivatives are known in pharmaceuticals as well as in agrochemical products.2-7 This class of compounds has also found application in drug devolvement for the treatment of allergies,8 hypertension,9 schizophrenia,10 inflammation,11 bacterial12 and HIV13 infections. Aminothiazoles are known to be ligands of estrogen receptors14 as well as a novel class of adenosine receptor antagonists15 whereas other analogues are used as fungicides, inhibiting in vivo growth of xanthomonas and as an ingredient of of herbicides or as schistosomicidal and anthelmintic drugs.16 Thiazoles are a prominent class of heterocycles, being investigated for further applications such as liquid crystals17 and molecular diodes.18 The interest in substituted thiazoles with reactive functionalities resides also in their synthetic potential as building blocks for natural product synthesis19 and/or as masked aldehydes.20 Furthermore, synthetic thiazoles offer the opportunity to increase the structural diversity of natural thiazole Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, amaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

376

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa substrates. The thiazolium ring present in vitamin B1 serves as an electron sink and its

coenzyme form is important for the decarboxylation of -keto acids.21 Several methods22 for the synthesis of thiazole derivatives were developed by Hantzsch, Tcherniac, Cook–Heilbron, Gabriel and several other groups, amongst which, the most widely used method is Hantzsch’s synthesis.23 This synthesis involves the reaction between a halocarbonyl compound and thioamides, thioureas or thiocarbamic acid derivatives or dithiocarbamic acid derivatives. Relatively newer methods involve cycloaddition of TosMIC to thione derivatives,24 oxidation of thiazoline/thiazolidine ring systems,25 Ugi reaction26 and others.27 Recently, palladium-mediated coupling processes (Suzuki coupling,28 Stille reaction29 and Negishi coupling30) have emerged as powerful tools to introduce various aryl and olefinic moieties into the thiazole ring systems. Nucleophilic reactions of lithiothiazole31 also afford substituted thiazoles.

2. RESULTS AND DISCUSSION Having synthesized new heterocyclic compounds from nitrones derived from 2methoxy/hydroxy-5-aryl substituted benzaldehydes, it is planned exploit the synthetic utility of this aldehyde for the construction of other heterocycles. A heterocycle with nitrogen and sulfur may be of interest and the presence of hydroxyl group in the ortho position of the phenyl ring in the side chain may have added interest as the resultant molecule may possess significant biological activity and possible hydrogen bonding. With this view, it is planned to prepare a new set of thiazoles. Initially thiosemicarbazones of 2-hydroxy-5-substituted arylaldehydes have been prepared by reacting the aldehyde with thiosemicarbazide (Scheme 1). Table 1 indicates the reaction time and yield for the different substituted systems.

OH

OH CHO

H N

S H 2N

N

C

NH 2

NH 2

N

EtOH, Reflux

S

H R

1

R

2

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

377

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa

Scheme 1 Table 1

Comp.

R

Reaction time (h)

Yield (%)

2a

C(CH3)3

2

85

2b

OCH3

3

83

2c

C(CH3)2CH2CH3

3

78

All the three semicarbazones are obtained in good yield and hitherto unreported. The 1

H NMR spectrum of 2a (Figure 1) gives a singlet for nine hydrogens at 1.29 ppm. There is

a one hydrogen doublet at 6.87 ppm with a coupling constant of 8.40 Hz. There is a multiplet around 7.30 ppm accounting for two hydrogens. There is a singlet at 8.23 ppm accounting for one hydrogen which can be assigned to the azomethine hydrogen. The one hydrogen signal at 9.52 ppm and another one hydrogen signal at 11.23 ppm can all be assigned to the replacable hydrogens on oxygen and nitrogen. In the 13C NMR spectrum (Figure 2), the thiocarbonyl carbon appears at 177.0 ppm. The carbon ipso to hydroxyl appears at 154.3 ppm and the azomethine carbon appears at 146.5 ppm. The semicarbazones 2 were then treated with substituted phenacyl bromides (3) prepared from the respective acetophenones. Reaction took place smoothly in DMF-ethanol leading to the formation of the single product 4 in quantitative yield (Scheme 2). The compound obtained, 4, was identified as 5-substituted 2-hydroxybenzaldehyde 1-(4-aryl-1,3thiazol-2-yl)hydrazone. The details of the compounds prepared are given in Table 2.


378

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa O OH H Br N NH 2 N S

X

R

2

3 EtOH DMF Ref lux

OH H N

N

N

X

S R

4

Scheme-2 Table 2

Compd

R

X

Reaction

Yield

time (h)

(%)

4a

C(CH3)3

Cl

3

85

4b

C(CH3)3

H

3

85

4c

OCH3

H

3

83

4d

C(CH3)2CH2CH3

H

3

80

4e

C(CH3)3

CH3

4

78

4f

C(CH3)3

OCH3

4

81

4g

C(CH3)2CH2CH3

CH3

3

84


379


4h

C(CH3)2CH2CH3

OCH3

4

80

4i

C(CH3)2CH2CH3

Cl

3

82

4j

OCH3

CH3

3

85

4k

OCH3

OCH3

4

84

4l

OCH3

Cl

3

81

All the synthesized twelve thiazole derivatives are new and they were characterized by

1

H NMR,

13

C NMR and several 2D-NMR techniques. The 1H NMR spectrum of 4a

(Figure 3) exhibits a singlet at 1.25 ppm for nine hydrogens and a bunch of signals from 6.57 to 7.86 ppm in the aromatic region. The acidic NH proton appears at 9.96 ppm. In the 13C NMR spectrum (Figure 4) of 4a, signals at 169.2, 154.9, 149.7, 144.7, 142.3, 134.1, 132.7, 129.1, 128.6, 127.5, 126.6, 116.5, 116.2, 103.4, 33.9 and 31.4 ppm are observed. The H-H COSY spectrum (Figure 5) shows connectivity between signals at 7.75 ppm and 7.36 ppm and 7.28 ppm and 6.89 ppm. The signal at 6.89 ppm is a doublet and it can be assigned to H3 of the aryl ring. The signal at 7.28 which is a multiplet can be assigned to H-4. There are signals at 6.60, 7.47 and 7.85 ppm which do not have coupling partners. Obviously, the signals at 7.36 and 7.75 ppm are due to the hydrogens of the p-chlorophenyl ring. The signal at 6.89 has HMBC (Figure 7) contours with the signal at 169.2 ppm and 149.7 ppm and hence, this can be assigned to the lone hydrogen of the thiazolyl ring, H-9. The signals at 162.2 and 149.7 ppm are obviously due to C-10 and C-8 respectively. The singlet at 7.47 ppm gives HMBC contour with two quarternary carbons at 154.9 and 116.5 ppm. This hydrogen can be assigned to azomethine hydrogen and hence the carbons at 154.9 and 116.5 can be assigned to C-1 and C-2 carbon. The signal at 7.75 ppm gives HMBC contour with the carbon at 149.7 ppm, so these hydrogens are 2’,6’ hydrogens of the p-chlorophenyl ring. Obviously the signal at 7.36 ppm is due to the 3’,5’ hydrogens of the p-chlorophenyl ring. The signal at 142.3 ppm can be assigned to C-5, as it gives a strong HMBC contour with the t-butyl methyl hydrogens. This carbon also has a HMBC contour with the hydrogen at 6.89 ppm. As the signal at 7.85 ppm gives a HMBC contour with a carbon at 116.2 ppm, it is the hydroxyl hydrogen and the latter carbon is C-3. From these and other spectral data, all the carbons and hydrogens of 4a can be assigned as shown below. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

380

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa 7.85

7.47

OH 6.89

H

154.9

2

H

146.7 7

4 5

142.3

127.5

H N N

H 6.60

33.8

H

H

9.97

6 128.6

126.6 7.28

H 1116.5

116.2 3

7.36

7.75

5'

6'

N

4'

132.7 10

169.2 8

134.1

1'

S 103.4

9

129.1

149.7

H

Cl

2'

H

3'

H

6.80 1.27

31.4

In order to investigate the influence of microwave irradiation on the reaction of the 2{(E)-1-[5-substituted 2-hydroxyphenyl]methylidene}-1-hydrazine carbothioamide 2 with substituted phenacyl bromides 3, an equimolar well ground mixture of these two compounds without any solvent was irradiated in a domestic microwave oven for two minutes. The reaction mixture upon working up has found to contain a single compound identified as 5substituted 2-hydroxybenzaldehyde 1-(4-aryl-1,3-thiazol-2-yl) hydrazone, 4 in good yield.

3. EXPERIMENTAL All chemicals were of reagent grade quality and used with out further purification. All melting points were recorded in open capillaries and are uncorrected. The 1H, and 13C NMR spectra were recorded on a Bruker 300 MHz spectrometer at 300 MHz and 75 MHz respectively in CDCl3 using TMS as internal standard. The related 2D NMR spectra were also recorded on the same instrument. Chemical shifts are given in parts per million (-scale) and coupling constants are given in Hertz. Micro analyses were carried out on a Perkin-Elmer instrument. All chromatographic separations were performed on 60-120 mesh silica gel using petroleum ether- ethyl acetate as eluent. I. Preparation of 2-{(E)-1-[5-substituted -2-hydroxyaryl] methylidene}-1-hydrazine carbothioamide (2) General procedure: To a warm solution of 0.01 m of the appropriate 5-substituted-2hydroxybenzaldehyde 1 in 30 ml of ethanol, a solution of equimolar amount of and Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

381


thiosemicarbazide (5.57 g, 0.05 m) and anhydrous sodium acetate (4.1 g, 0.05 m) in 20 ml of water was added and refluxed for 2-3 hours. The solution was cooled and poured into crushed ice.

The

precipitated

semicarbazone

2-{(E)-1-[5-substituted

-2-hydroxyphenyl]

methylidene}-1-hydrazine carbothioamide 2 was washed with water, dried and recrystallised from ethanol. The details of compounds prepared based on this general procedure are given below. 2-(E)-1-[5-(t-Butyl)-2-hydroxyphenyl]methylidene-1-hydrazine carbothioamide (2a) This compound was obtained as a white solid, mp, 198 C; 1H NMR (300 MHz, CDCl3): δ =1.29 (s, 9H), 6.87 (d, 1H, J = 8.4 Hz), 7.30 (m, 2H), 8.23 (s, 1H), 9.52 (s, 1H), 11.23 (s, 1H);

13

C nmr (75 MHz, CDCl3): δ = 30.8, 33.4, 115.6, 116.7, 126.4, 128.4, 141.8,

146.5, 154.3, 177.0. Reaction time: 2 h

Yield = 85 %

2-[(E)-1-(2-Hydroxy-5-methoxyphenyl)methylidene]-1-hydrazine carbothioamide (2b) This compound was obtained as a white solid, mp, 193 C; 1H NMR (300 MHz, CDCl3): δ =3.77 (s, 3H), 6.85 (d, 1H, J = 8.4 Hz), 7.05 (m, 2H), 8.21 (s, 1H), (9.23, s, 1H), 11. 30 (s, 1H); 13C nmr (75 MHz, CDCl3): δ = 55.9, 117.0, 119.7, 119.9, 141.1, 152.7, 155.9, 170.8, 177.5. Reaction time: 3 h

Yield = 83 %

2-(E)-1-[2-Hydroxy-5-(t-pentyl)phenyl]methylidene-1-hydrazine carbothioamide (2c) This compound was obtained as a white solid, mp, 197 C; 1H NMR (300 MHz, CDCl3): δ =1.25 (s, 6H), 0.65 (3H, t, J = 7.2 Hz), 1.60 (2H, q, J = 7.2 Hz), 6.90 (d, 1H, J = 8.7 Hz), 7.03 (m, 2H), (8.20, s, 1H), (9.49, s, 1H), 11.40 (s, 1H);

13

C NMR (75 MHz,

CDCl3): δ = 8.79, 28.1, 36.3, 36.8, 115.8, 117.1, 127.1, 129.1, 140.2, 146.4, 154.4, 177.3. Reaction time: 3 h

Yield = 78 %

II. Preparation of 5-substituted-2-hydroxy benzaldehyde 1-(4-aryl-1,3-thiazol-2yl)hydrazone (4) General procedure: An equimolar mixture of 2-{(E)-1-[5-substituted-2-hydroxy phenyl] methylidene}-1-hydrazine carbothioamide 2 (0.005 m) and p-substituted phenacyl bromide 3 (0.005 m) were warmed in 25 ml of ethanol. Dimethylformamide was added Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

382


dropwise till a clear solution was obtained. It was further refluxed for 4 hours. The solution was cooled and poured into crushed ice. The precipitated 5-substituted-2-hydroxy benzaldehyde 1-(4-aryl-1,3-thiazol-2yl)-hydrazone 3 was washed with water, dried and recrystallised from ethanol. The details of compounds prepared based on this general procedure are given below. 5-(t-Butyl)-2-hydroxybenzaldehyde 1-[4-(4-chlorophenyl)-1,3-thiazol-2-yl]hydrazone (4a) This compound was obtained as a yellow solid, mp, 162 C; 1H NMR (300 MHz, CDCl3): δ =1.27 (s, 9H), 6.60 -7.82 (m, 9H), (7.82, s, 1H), 9.97 (s, 1H); 13C NMR (75 MHz, CDCl3): δ =31.4, 33.9, 103.4, 116.2, 116.5, 126.6, 127.5, 128.6, 129.1, 132.7, 134.1, 142.3, 144.7, 149.7, 154.9, 169.2. Anal. Calcd. for C20H20 ClN3OS: C, 62.25; H, 5.22; N, 10.89%. Found: C, 62.17; H, 5.15; N, 10.80%. Reaction time: 3 h Yield = 85 % 5-(t-Butyl)-2-hydroxybenzaldehyde 1-(4-phenyl-1,3-thiazol-2-yl)hydrazone (4b) This compound was obtained as a yellow solid, mp, 159 C; 1H NMR (300 MHz, CDCl3): δ = 1.25 (s, 9H), 6.80-7.90 (m, 10H), 9.95 (s, 1H); 13C NMR (75 MHz, CDCl3):

δ

=31.2, 33.7, 102.2, 116.8, 118.7, 126.7, 127.5, 128.3, 128.4, 134.3, 134.9, 141.7, 144.8, 150.7, 154.4, 167.5. Anal. Calcd. for C20H21N3OS: C, 68.35; H, 6.02; N, 11.96%. Found: C, 68.25; H, 5.96; N, 11.87%. Reaction time: 3 h Yield = 85 % 5-Methoxy2-hydroxybenzaldehyde 1-(4-phenyl-1,3-thiazol-2-yl)hydrazone (4c) This compound was obtained as a yellow solid, mp, 192 C;

1

H NMR (300 MHz,

CDCl3): δ = 3.70 (s, 3H), 6.60 (d, 1H, J = 2.7 Hz), 6.84 (m, 3H), 7.79 (d, 2H, J = 7.8 Hz), 7.90 (s, 1H), 9.90 (s, 1H); 13C NMR (75 MHz, CDCl3): δ = 55.6, 102.2, 113.6, 117.1, 117.9, 125.7, 127.7, 128.5, 134.4, 144.7, 150.7, 151.2, 152.3 Anal. Calcd. for C17H15N3O2S: C, 62.75; H, 4.65; N, 12.91%. Found: C, 62.65; H, 4.55; N, 12.81%. Reaction time: 3 h Yield = 83 %


383

Synthesis and characterization of 5-substituted-2-hydroxybenzaldehyde 1-(4-aryl-1, 3-thiazol-2yl)hydrazones S. R. jayapradhaa 5-(t-Pentyl)-2-hydroxybenzaldehyde 1-(4-phenyl-1,3-thiazol-2-yl)hydrazone (4d)

This compound was obtained as a yellow solid, mp, 164 C; 1H NMR (300 MHz, CDCl3): δ = 0.64 (3H, t, J = 7.2 Hz), 1.21 (s, 6H), 1.56 (2H, q, J = 7.2 Hz), 6.80-7.80 (m, 10H), 7.65 (s, 1H), 9.50 (s, 1H); 13C NMR (75 MHz, CDCl3): The compound is not soluble enough in the CDCl3 for taking 13C experiment. Anal. Calcd.for C21H23N3OS: C, 69.01; H, 6.34; N, 11.50%. Found: C, 69.93; H, 6.26; N, 11.38%. Reaction time: 3 h Yield = 80 % 5-(t-Butyl)-2-hydroxybenzaldehyde 1-[4-(4-methylphenyl)-1,3-thiazol-2-yl]hydrazone (4e) This compound was obtained as a yellow solid, mp, 155 C; 1H NMR (300 MHz, CDCl3): δ =1.34 (s, 9H), 2.30 (s, 3H), 6.60-7.80 (m, 9H), 7.82 (s, 1H);

13

C NMR (75 MHz,

CDCl3): δ =21.6, 31.7, 34.3, 102.2, 116.4, 116.6, 126.3, 127.1, 128.2, 129.8, 132.1, 137.7, 142.4, 146.6, 151.2, 155.3, 168.9. Anal. Calcd. for C21H23 N3OS: C, 69.01; H, 6.34; N, 11.50%. Found: C, 68.91; H, 6.24; N, 11.41%. Reaction time: 4 h Yield = 78 % 5-(t-Butyl)-2-hydroxybenzaldehyde 1-[4-(4-methoxyphenyl)-1,3-thiazol-2-yl] hydrazone (4f) This compound was obtained as a yellow solid, mp, 169 C; 1H NMR (300 MHz, CDCl3): δ = 0.64 (3H, t, J = 7.2 Hz), 1.21 (s, 6H), 1.56 (2H, q, J = 7.2 Hz), 6.80-7.80 (m, 9H), 7.85 (s, 1H); The compounds is not soluble enough in the NMR solvents for recording 13

C NMR spectrum.

Anal. Calcd. for C21H23 N3O2S: C, 66.12; H, 6.08; N, 11.01%. Found: C, 66.02; H, 5.98; N, 10.91%. Reaction time: 4 h Yield = 81 % 5-(t-Pentyl)-2-hydroxybenzaldehyde 1-[4-(4-methylphenyl)-1,3-thiazol-2-yl] hydrazone (4g) This compound was obtained as a yellow solid, mp, 161 C; 1H NMR (300 MHz, CDCl3): δ = 0.64 (3H, t, J = 7.2 Hz), 1.21 (s, 6H), 1.56 (2H, q, J = 7.2 Hz), 6.80-7.80 (m, 9H), 7.85 (s, 1H); 7.90 (s, 1H), 9.90 (s, 1H); The compounds is not soluble enough in the NMR solvents for recording 13C NMR spectrum.


384


Anal. Calcd. for C22H25 N3OS: C, 69.62; H, 6.64; N, 11.07%. Found: C, 68.53; H, 6.54; N, 10.97%. Reaction time: 3 h Yield = 84% 5-(t-Pentyl)-2-hydroxybenzaldehyde 1-[4-(4-methoxyphenyl)-1,3-thiazol-2-yl]hydrazone (4h) This compound was obtained as a yellow solid, mp, 154 C; 1H NMR (300 MHz, CDCl3): δ = 0.64 (3H, t, J = 7.2 Hz), 1.21 (s, 6H), 1.56 (2H, q, J = 7.2 Hz), 6.80-7.80 (m, 9H), 7.85 (s, 1H); 7.90 (s, 1H), 9.90 (s, 1H); The compounds is not soluble enough in the NMR solvents for recording 13C NMR spectrum. Anal. Calcd. for C22H25 N3O2S: C, 66.81; H, 6.37; N, 10.62%. Found: C, 66.72; H, 6.25; N, 10.55%. Reaction time: 4 h Yield = 80 % 5-(t-Pentyl)- 2-hydroxybenzaldehyde 1-[4-(4-chlorophenyl)-1,3-thiazol-2-yl]hydrazone (4i) This compound was obtained as a yellow solid, mp, 157 C; 1H NMR (300 MHz, CDCl3): δ = 0.64 (3H, t, J = 7.2 Hz), 1.21 (s, 6H), 1.56 (2H, q, J = 7.2 Hz), 6.80-7.80 (m, 9H), 7.85 (s, 1H); 7.90 (s, 1H), 9.90 (s, 1H); The compounds is not soluble enough in the NMR solvents for recording 13C NMR spectrum. Anal. Calcd. for C21H22 ClN3OS: C, 63.07; H, 5.54; N, 10.51%. Found: C, 62.96; H, 5.44; N, 10.41%. Reaction time: 3 h Yield = 82 % 5-Methoxy-2-hydroxybenzaldehyde 1-(4-methylphenyl-1,3-thiazol-2-yl)hydrazone (4j) This compound was obtained as a yellow solid. mp, 168 C; The compound is not at all soluble in NMR solvents for recording 1H and 13C spectra. Anal. Calcd. for C18H17N3O2S: C, 63.70; H, 5.05; N, 12.38%. Found: C, 63.60; H, 4.95; N, 12.27%. Reaction time: 3 h Yield = 85 % 5-Methoxy-2-hydroxybenzaldehyde 1-(4-methoxyphenyl-1,3-thiazol-2-yl)hydrazone (4k) This compound was obtained as a yellow solid, mp, 153 C; The compound is not at all soluble in NMR solvents for recording 1H and 13C spectra. Anal. Calcd. for C18H17N3O3S: C, 60.83; H, 4.82; N, 11.82%. Found: C, 60.73; H, 4.71; N, 11.72%. Reaction time: 4 h Yield = 84 % Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

385


5-Methoxy-2-hydroxybenzaldehyde 1-(4-chlorophenyl-1,3-thiazol-2-yl)hydrazone (4l) This compound was obtained as a yellow solid, mp, 171 C; The compound is not at all soluble in NMR solvents for recording 1H and 13C spectra. Anal. Calcd. for C17H14 ClN3O2S: C, 56.74; H, 3.92; N, 11.68%. Found: C, 56.66; H, 3.57; N, 11.54%. Reaction time: 3 h

Yield = 81 %

4. REFERENCES 1.

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Patt, W. C.; Hamilton, H. W.; Taylor, M. D.; Ryan, M. J.; Taylor, D. G., Jr.; Connolly, C. J. C.; Doharty, A. M.; Klutchko, S. R.; Sircar, I.; Steinbaugh, B. A.; Bately, B. L.; Painchand, C. A.; Rapundalo, S. T.; Michniewicz, B. M.; Olzon, S. C. J. J. Med. Chem. 1992, 35, 2562.

10.

Jaen, J. C.; Wise, L. D.; Caprathe, B. W.; Tecle, H.; Bergmeier, S.; Humblet, C. C.; Heffner, T. G.; Meltzner, L. T.; Pugsley, T. A. J. Med. Chem. 1990, 33, 311.

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(a) Haviv, F.; Ratajczyk, J. D.; DeNet, R. W.; Kerdesky, F. A.; Walters, R. L.; Schmidt, S. P.; Holms, J. H.; Young, P. R.; Carter, G. W. J. Med. Chem. 1988, 31, 1719. (b) Clemence, F.; Marter, O. L.; Delevalle, F.; Benzoni, J.; Jouanen, A.; Jouquey, S.;

Mouren, M.; Deraedt, R. J. Med. Chem. 1988, 31, 1453. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 376 - 388 Editors: Dr S Rajendran, A Christy Catherine Mary

386


12.

Tsuji, K.; Ishikawa, H. Bioorg. Med. Chem. Lett. 1994, 4, 1601.

13.

Bell, F. W.; Cantrell, A. S.; Hoberg, M.; Jaskunas, S. R.; Johansson, N. G.; Jordon, C. L.; Kinnick, M. D.; Lind, P.; Morin, J. M., Jr.; Noreen, R.; Oberg, B.; Palkowitz, J. A.; Parrish, C. A.; Pranc, J.; Zhang, H.; Zhou, X.-X. J. Med. Chem. 1995, 38, 4929.

14.

Fink, B. A.; Mortensen, D. S.; Stauffer, S. R.; Aron, Z. D.; Katzenellenbogen, J. A. Chem. Biol. 1999, 6, 205.

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Van Muijlwijk-Koezen, J. E.; Timmerman, H.; Vollinga, R. C.; Von Drabbe Kunzel, J. F.; De Groote, M.; Visser, S.; Ijzerman, A. P. J. Med. Chem. 2001, 44, 749.

16.

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Mori, A.; Sekiguchi, A.; Masui, K.; Shimada, T.; Horie, M.; Osakada, K.; Kawamoto, M.; Ikeda, T. J. Am. Chem. Soc. 2003, 125, 1700.

18.

Ng, M.; Yu, L. Angew. Chem., Int. Ed. 2002, 41, 3598.

19.

(a) Nicolaou, K. C.; Sarabia, F.; Ninkovic, S.; Finlay, M. R.; Boddy, C. N. C. Angew. Chem., Int. Ed. 1998, 37, 81. (b) Kelly, T. R.; Lang, F. J. Org. Chem. 1996, 61, 4623. (c) Nicolaou, K. C.; King, N. P.; Finlay, M. R. V.; He, Y.; Roschangar, F.; Vourloumis, D.; Vallberg, H.; Sarabia, F.; Ninkovic, S.; Hepworth, D. Bioorg. Med. Chem. 1999, 7, 665.

20.

Dondoni, A.; Marra, A. Chem. Rev. 2004, 104, 2557.

21.

Breslow, R. J. Am. Chem. Soc. 1958, 80, 3719.

22.

Metzger, J. V. In Comprehensive Heterocyclic Chemistry 1984, 6, 235.

23.

(a) Hantzsch, A.; Weber, J. H. Ber. Dtsch. Chem. Ges. 1887, 20, 3118. (b) Aguilar, E.; Meyers, A. I. Tetrahedron Lett. 1994, 35, 2473. (c) Varma, R. S. Pure Appl. Chem. 2001, 73, 193. (d) Ochiai, M.; Nishi, Y.; Hashimoto, S.; Tsuchimoto, Y.; Chen, D.-W. J. Org. Chem. 2003, 68, 7887 and references cited therein.

24.

Bergstrom, D. E.; Zhang, P.; Zhou, J. J. Chem. Soc. Perkin Trans. 1994, 1, 3029.

25.

(a) Martin, L. M.; Hu, B. H. Tetrahedron Lett. 1999, 40, 7951. (b) You, S. L.; Kelly, J. W. J. Org. Chem. 2003, 68, 9506.

26.

Kazmaier, U.; Ackermann, S. Org. Biomol. Chem. 2005, 3, 3184.


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(a) Mustafa, S. M.; Nair, V. A.; Chittoor, J. P.; Krishnapillai, S. Mini-Rev. Org. Chem. 2004, 1, 375. (b) Walek, W.; Pallas, M.; Augustin, M. Tetrahedron 1976, 32, 623. (c) Golankiewicz, B.; Januszczyk, P.; Gdaniec, M.; Kosturkiewicz, Z. Tetrahedron 1985, 41, 5989. (d) Lin, Y.-I.; Seifert, C. M.; Kang, S. M.; Dusza, J. P.; Lang, S. A., Jr. J. Heterocycl. Chem. 1979, 16, 1377. (e) Short, K. M.; Ziegler, C. B., Jr. Tetrahedron Lett. 1993, 34, 71.



388

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3

THE INFLUENCE OF CTAB WITH WATER SOLUBLE POLYMER TO CONTROL THE CORROSION OF CARBON STEEL S.Anithaa, A. John Amalraja*, V. Dharmalingama, J. Wilson Sahayarajb and P. Johnrajc [a] PG and Research Department of Chemistry, Periyar E.V.R College, Trichy – 620 023, Tamil Nadu, India. Email: [email protected] [b] Department of Chemistry, Jeppiaar Engineering College, Chennai- 600 119, Tamil Nadu, India. [c] Post Graduate Department of Chemistry, Nehru Memorial College (Autonomous), Trichy, India. Abstract The corrosion inhibition effect of carbon steel in ground water by polyacrylic acid (PAA)- Mg2+ system has been evaluated using classical weight-loss method. The influence of N- Cetyl-N,N,N Trimethyl Ammonium Bromide (CTAB) on (PAA)- Mg2+ system has also studied. The PPAMg2+-CTAB offer 71% of inhibition efficiency. The synergistic effect exists between CTAB Mg2+ - PAA systems. The mixed inhibitors show better inhibition efficiency than individual. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


389

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 Polarization study reveals that this formulation controls the anodic reaction predominantly. AC impedance spectra prove the protective film formation on the carbon steel. FTIR spectra reveals that the protective film consists of Fe2+ - CTAB complex and Fe2+ - PAA complex formed on anodic sites of metal surface and Mg(OH)2 formed on cathodic sites of metal surface. The SEM study proves the protective film formed on the metal surface. The EDS study determines the elements of CTAB - Mg2+ - PAA system on the carbon metal surface. The mechanistic aspects of corrosion inhibition based on the results obtained from the classical weight-loss method and the electrochemical method such as AC impedance and polarization study. Keywords: Carbon steel; polyacrylic acid; Inhibition efficiency; protective film; 1.Introduction Corrosion inhibitors protect the surface of metal from the corrosion. The organic, inorganic inhibitors are being widely used as corrosion inhibitors. Polymers can be made from inorganic or organic molecules. Although synthetic polymers, organic and inorganic compounds were applied as inhibitors to reduce the dissolution of Al in alkaline media, little attention has been focused on application of natural polymers as dissolution inhibitors in alkaline medium. The corrosion inhibition by various cationic polymers such as polyethyleneimine derivative, polyacrylamide derivative, polydicyanodiamide derivative, and anionic polymers such as polymaleic acid derivative, polyacrylic acid derivative, and polyacrylic acid, have been investigated[1-6]. The present paper objectives are: 1. To study the corrosion inhibition percentage of polyacrylic acid (PPA) –Mg2+ system on carbon steel in well water environment. 2. To enhance the inhibition efficiency of PPA, the surfactant CTAB added. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


390

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 3. To study the electrochemical behavior of inhibitors analyze by potentiodynamic polarization study and AC impedance spectra. 4. To investigate the adsorbed substance formed on the carbon steel by SEM, EDS and FTIR spectrophotometer. 5. To frame the possible corrosion prevention mechanism are given by results obtained in this study. 2. Methodology 2.1 Preparation of the specimen Carbon steel (0.026%S, 0.06%P, 0.4%Mn, 0.1% C, and the rest Fe) specimen of dimension 1 cm x 4 cm x 0.2 cm were used for weight-loss study. Carbon steel specimens polished to mirror finish with help of emery paper of different grade and cleansed with the solvent trichloroethylene. 2.2 Weight loss method Carbon steel specimens in triplicate were suspended by means of glass hooks in 100 ml of well water containing various concentrations of the inhibitors, in the absence, presence of, and Mg2+ ions, for a period of seven days. The parameters of well water are given in Table 1. The weight of the specimens was determined using Shimadzu balance, AY62 model. The corrosion products formed on the carbon steel were cleansed with Clarke’s solution[7]. The corrosion rates (CR) of the metal specimens were calculated by the given relationship: Where CR = ∆m/A*t CR - corrosion rate Δm - loss in weight (mg) A - surface area of the specimen (dm2) Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


391

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 t - Period of immersion (days) The corrosion inhibition efficiency (IE) was calculated by using the equation

Where, W1 and W2 are the corrosion rates in the absence and presence of the inhibitor respectively. Table 1: Parameters of well water

S.NO

Parameters

Value

1.

PH

8.19

2.

Electrical Conductivity (µs)

1068

3.

Total Dissolved Solids (TDS) (mg/lit)

728

4.

Chloride ( mg/lit)

164

5.

Sulphate (mg/lit)

10

6.

Total Hardness (mg/lit)

490

2.3 Polarization study Polarization studies recorded with help of CHI electrochemical impedance analyzer, model 660A. A three-electrode cell set up used in this work. A rectangular carbon steel with one face of the electrode exposed to the air and the rest shielded with red lacquer was working electrode. A saturated calomel electrode (SCE) and a rectangular platinum foil were used as the reference and counter electrode respectively. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


392

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 2.4 AC impedance study The cell set up used was similar to the polarization measurement. The impedance experiments were carried out at various frequencies. The real part (Z) and imaginary part(Z’) of the cell impedance were observed. The charge transfer resistance (Rt) and the double layer capacitance (Cd1) were analyzed. 2.5 Surface analysis The carbon steel specimens were suspended by means of glass hook in the presence of inhibitor systems for seven days. After seven days, the specimens were taken out from the beaker, washed with double distilled water and dried by using drier. The film formed on the metal surface can be used for surface examination studies. 2.6 Analysis of FTIR Spectra The adsorbed substance formed on the carbon steel specimen carefully removed with sharp edged glass rod, mixed with KBr and made into pellets. Perkin- Elmer 1600 spectrophotometer was used for this study. 2.7 SEM / EDS study The Surface structure of the carbon steel specimens examined by using JEOL JSM 6390 model. All SEM micrographs of carbon steel are taken at a magnification of X=500. 3. Results and discussion 3.1 Analysis of Weight – loss study The corrosion rate(CR) and corrosion inhibition effect(IE) of carbon steel specimens immersed in well water environment in absence and presence of inhibitor systems are given in table 2 -5. Table 2: Corrosion inhibition efficiency(IE)) of Carbon in the presence and absence of inhibitor and obtained by weight - loss method Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


393

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 Inhibitor system: CTAB system Immersion Period: 7 days

CTAB

CR

I.E

(ppm)

(mdd)

%

1.

0

-

-

2.

100

26.88 -78.44

3.

200

20.00 -32.75

4.

300

24.41 -62.06

5.

400

10.77

28.44

6.

500

5.32

64.65

7.

600

7.27

51.72

S.NO

It is observed from table 1 that the PPA alone is poor inhibitor. The addition of Mg2+ shows low IE. But addition of CTAB to the PPA – Mg2+ system has better inhibition efficiency. For example, 50 ppm of Mg2+,500 ppm PPA and 300 ppm of CTAB shows 71% IE. This strongly indicates that a synergistic effect[8,9] appears between CTAB – Mg2+-PPA system. Table 3: Corrosion inhibition efficiency(IE)) of Carbon in the presence and absence of inhibitor and obtained by weight - loss method Inhibitor system: PPA system

Immersion Period: 7 days S.NO

PPA

CR

I.E



394

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 (ppm) (mdd) % 1.

0

-

-

2.

100

12.07

19.82

3.

200

11.94

20.68

4.

300

11.16

25.86

Corrosion

5.

400

10.51

30.17

inhibition

of Carbon in the presence

6.

500

9.35

37.93

and absence of inhibitor

and obtained by weight -

7.

600

8.70

42.24

loss method

Table

4:

Inhibitor system: PPA – Mg2+ system

efficiency(IE))

Immersion Period: 7 days

PPA

Mg2+

(ppm)

(ppm) (mdd)

CR

I.E

S.NO %

1.

0

0

-

-

2.

500

10

6.36

57.75

3.

500

20

6.49

56.89

4.

500

30

6.88

54.31

5.

500

40

7.53

50.00

6.

500

50

7.66

49.13

7.

500

60

8.57

43.96



395


Table 5: Corrosion inhibition efficiency(IE)) of Carbon in the presence and absence of inhibitor and obtained by weight - loss method Inhibitor system: PPA – Mg2+-CTAB system

Immersion Period: 7 days

PAA

Mg2+

CTAB

CR

I.E

(ppm)

(ppm)

(ppm)

(mdd)

%

1.

0

0

0

-

-

2.

500

50

100

6.88

54.31

3.

500

50

200

6.49

56.89

4.

500

50

300

4.28

71.50

5.

500

50

400

7.01

53.44

6.

500

50

500

7.79

48.27

7.

500

50

600

8.31

44.82

S.NO

3.2 Analysis of Polarization study The potentiodynamic polarization studies were carried out to determine the kinetics of the cathodic and anodic reactions. Figure1. Shows the potentiodynamic polarization curves for mild steel electrodes in well water in the absence and presence of various inhibitor combinations. Electrochemical kinetic parameters, i.e., the corrosion potential (Ecorr), corrosion current density Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


396

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 (Icorr), and anodic and cathodic tafel slopes (ba and bc), obtained from extrapolation of the polarization curves are listed in Table 6. When carbon steel is immersed in well water, the corrosion potential (Ecorr) is -576 mV/dec and the corrosion current is 9.19 μA/cm2. When 300 ppm CTAB to 500 ppm of PAA and 50 ppm Mg2+ are added to well water medium the corrosion potential is shifted toward anodic side and it is found to be -551 mV/dec and corrosion current is 2.80 μA/cm2. The corrosion current decreases from 9.19 μA/cm2 to 2.80μA/cm2. The tafel slopes for the formulation is almost same. This shows that the formulation functions act as mixed inhibitor type. Table 6: Corrosion parameters of mild steel immersed in the absence and presence of inhibitor obtained by potentiodynamic polarization studies Concentration (ppm) PAA

CTAB

Ecorr (mV/dec)

0

0

0

- 576

9.19

149

170

50

500

300

- 551

2.80

183

179

Mg

2+

Icorr (µA/cm2)

ba (mV/dec)

bc (mV/dec)



397

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 Figure. 1. Potentiodynamic polarization curves of carbon steel a). Well water b). 50 ppm Mg2+ + 500 ppm PAA + 300 ppm CTAB Analysis of Electrochemical Impedance spectroscopy The Nyquist plots for the corrosion behavior of carbon steel immersed in various solutions are shown in Figure.2. The AC impedance parameters, namely, charge transfer resistance (Rt) and double layer capacitance (Cdl) are given in (Table 7). The carbon steel immersed in well water environment, Rt value of 18 Ω cm2 and Cdl value of 148x10-5 F cm-2 observed. When the formulation consisting of 50 ppm Mg2++ 500 ppm of PAA+ 300 ppm of CTAB added to well water environment, Rt value increases tremendously from 18 Ω cm2 to 60 Ω cm2. The Cdl value decreases from148x10-5 F cm-2 to 9.5x10-5 F cm-2. This suggests that a protective film formed on the surface of the metal. This accounts for the very high IE of PAA - Mg2+ - CTAB system.

Table 7: Corrosion parameters of mild steel immersed in the absence and

presence of

inhibitor obtained by AC impedance studies Concentration (ppm)

Rt

Cdl

(Ωcm2)

(F/cm2)

Mg2+

PAA

CTAB

0

0

0

18

148 x 10-5

50

500

300

60

9.5 x 10-5



398


Figure 2. AC impedance spectra curves of carbon steel in various test solutions a). Well water b). 50 ppm Mg2+ + 500 ppm PAA + 300 ppm CTAB 3.3 Analysis of Fourier transforms infrared spectroscopy The FTIR spectrum of pure PAA is shown in Figure 3a. The C=O stretching vibration at 1719 cm-1 and the broad absorption peak at 3448 cm-1 shows OH stretching vibration.



399


Transmittance (%)

(a)

-1 3448 cm -1 1719 cm

(b)

1464 cm

-1

-1 1656 cm -1 3385 cm

1092 cm

-1

4000 3500 3000 2500 2000 1500 1000

500

-1 Wave number (cm )

Figure 3. FTIR Spectra (a). Pure solid Polyacrylic acid (b). Film formed on the carbon steel after immersion of 50 ppm Mg2+ + 500 ppm PAA + 300 ppm CTAB The FT-IR spectrum of the film formed on the surface of mild steel after immersion in the solution consisting of 50 ppm of Mg2+, 500ppm PAA and 300 ppm of CTAB is shown in Figure 3b. It is observed that the OH stretching frequency of PAA decreases from 3448 cm-1 to 3385 cm-1.The C=O stretching frequency has decreased from 1719cm-1 to 1656cm-1. This shift is caused by the electron cloud density from the O atom of carbonyl groups to Fe2+. This suggests that the O atom of the polyacrylic acid is coordinate to Fe2+ resulting in the formation of Fe2+ PAA, complex on the metal surface. Further it is observed that the C-N stretching frequency CTAB has 1092cm-1. This suggests that CTAB has coordinate with Fe2+ through oxygen atom Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


400

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 resulting in the formation of Fe2+ - CTAB complex on the anodic sites of the metal surface[1011]. The peak at 1464 cm-1 is due to Mg(OH)2 on the cathodic Sites of the metal surface. Thus FTIR spectral study leads to the conclusion that the protective film consists of Fe2+ - PAA complex, Fe2+ - CTAB complex and Mg(OH)2. 3.6 Analysis of Scanning Electron Microscope SEM analysis provides a pictorial representation of the surface. To understand the nature of the surface film in the absence and presence of inhibitors and the extend of corrosion of carbon steel. Figure 4a show the polished metal surface of carbon steel before corrosion Figure 4b show the metal surface immersion of well water solutions. This shows the roughness of the metal surface by the corrosive environment and there is formation of different forms of corrosion products. Figure 4c show the metal surface immersion of 500 ppm PAA to of 300 ppm of CTAB and 50 ppm Mg2+ are added to well water- medium gives metal surface incorporating into the passive film in order to block the active site present on the carbon steel surface. Comparative examination of these images, clearly suggest that the surface of carbon steel is smoothened to a very large extent in the presence of the combined inhibitor system. This smoothening might be due to the adsorption of the inhibitor molecules on it and thus the surface is fully covered.



401

The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 Figure 4. SEM images of carbon steel (a) Polished carbon steel surface (b) Carbon steel immersed in well water (c) 50 ppm Mg2+ + 500 ppm PAA + 300 ppm CTAB 3.7 Analysis of Energy Dispersive X-ray Analysis The EDS spectra was used to determine the elements present on the surface of carbon steel absence and presence of inhibitors in the uninhibited and inhibited well water. Figure 5a gives characteristics peaks of the elements (Fe, Carbon and Mn) constituting the polished carbon steel specimen.



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Figure 5. EDS spectra of carbon steel (a) Polished carbon steel surface (b) Carbon steel immersed in well water (c) 50 ppm Mg2+ + 500 ppm PAA + 300 ppm CTAB Figure 5b portrays the EDS analysis of carbon steel in well water which indicates only the presence of Fe and O. This confirms that the passive film contained only . The EDS of presence of inhibitor Figure 3c in shows the presence of additional lines due to Fe, C, O, Cl, Mn and Fe. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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This may beat tribute to the presence of inhibitor on carbon steel which protects the steel surface from corrosion 4. Mechanism of corrosion inhibition In order to explain all the experimental results, the following mechanism of corrosion inhibition can be proposed[12-13]. Carbon steel undergoes initial corrosion to form Fe2+ ions at anodic sites: Fe

Fe2+ + 2e-

And the cathodic reaction is: O2 + 2H2O + 4e-

4OH_

When the environment containing 50ppm Mg2+-500 ppm PAA-300 ppm CTAB was prepared, a [Mg2+-PAA-CTAB] complex was formed in the solution. Besides this complex, there is presence of free PAA, CTAB and Mg2+ ions. While the metal was immersed in this environment, the [Mg2+-PAA and Mg2+ -CTAB] complex diffused from the bulk of the solution on to the surface of the metal and further complexes with Fe2+ ions available due to initial corrosion. Free PAA and CTAB molecules diffuse from the bulk of the solution to the metal surface and form [Fe2+PAA and Fe2+- CTAB] complexes. These complexes fill the pores of the film formed on the surface and make it productive. [Mg2+ - PAA] +Fe2+ [Mg2+– CTAB] +Fe2+

[Fe2+ - PAA] +Mg2+ [Fe2+ - CTAB] +Mg2+

Free Mg2+ ions diffuse from the bulk of the solution to the metal surface and form Mg(OH)2 at the local cathodic sites. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 Mg2+ + 2OHMg(OH)2 Thus, PAA, Mg2+ and CTAB play a very important role in the controlling corrosion through the formation of a protective film on the metal surface. 5.Conclusion The present study leads to the following conclusions: 

The formulation consisting of 50 ppm of Mg2+, 300 ppm of CTAB and 500 ppm of PAA offers 71% inhibition efficiency.



The synergistic effect exists between CTAB - Mg2+ - PAA systems. The mixed



inhibitors show better inhibition efficiency than individual.



Polarization study reveals that this formulation controls the anodic reaction predominantly.



AC impedance spectra prove the protective film formation on the carbon steel.



FTIR spectra reveals that the protective film consists of Fe2+ - CTAB complex and Fe2+ - PAA complex formed on anodic sites of metal surface and Mg(OH)2 formed on cathodic sites of metal surface.



The SEM study proves the protective film formed on the metal surface.



The EDS study determines the elements of CTAB - Mg2+ - PAA system on the carbon metal surface.

6. Acknowledgement The Authors are very much thankful to their respective managements 7. References [1 ] I Sekine, M Sanbongi, H Hagiuda, T Oshibe, M Yuasa, V Imahama, Y Shibata, T Wake, J Electrochem. Soc. 1992,139(11), 3167.



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The influence of CTAB with water soluble polymer to control the corrosion of carbon steel S.Anitha1, A. John Amalraj1*, V. Dharmalingam1, J. Wilson Sahayaraj2 and P. Johnraj3 [2 ] D.I. Bragadish, I.A. Mathakiya, A.K. Shah, A.K. Rakshit, Polymer International, 2000 49, 685.

[3 ] B. Muller, I Forster, W Klager, Progress Org. Coating 1997, 31(3), 229. [4 ] S.S. Abdel Rehim, F.M. Tohommy, M.M. Seleet, Surfactant Tech. 1984,21(2),169.

[5 ] K.S. Khairou, El Sayed A, J. Appl. Polymer Sci., 2003,88(4), 866. [6 ] S. Rajendran, S.P. Sridevi, N. Anthony, A. John Amalraj and M. Sundearavadivelu, AntiCorros. Method, 2005,52(2), 102.

[7 ] G.

Wranglen,

Introduction

to

Corrosion and

Protection

of

Metals(London,

U.K:Chapman and Hall), 236 (1985) [8 ] J. Wilson sahayaraj, A. John Amalraj , Susai Rajendran and N. Vijaya, Journal of Chemistry, 2012, 9(4), 1746. [9 ] Felicia Rajammal Selvarani, S Santhamadharasai, J. Wilson Sahayaraj, A. John Amalraj and S. Rajendran, Bulletin of Electrochem., 2004, 20, 561. [10 ] Nakamoto K., Infrared and Raman Spectra of Inorganic and Coordination Compounds, Wiley and Sons, New York, 4th edition, 95 (1986) [11 ] Silverstein R.M., Bassler G.C. and Morril T.C., Spectrometric Identification of Organic compounds, John Wiley and Sons, New York , 72 (1986). [12 ] S. K. Selvaraj, A. John Amalraj, V. Dharmalingam,bJ. Wilson Sahayaraj, Int. J Nano. Corr. Sci. Engg. 2016, 3(1), 96. [13 ] J. Wilson Sahayaraj, A. John Amalraj, Susai Rajendran, Journal of Chemical and Pharmaceutical Sciences, 2016, 9(3), 1491.



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CAN PEOPLE IMPLANTED WITH ORTHODONTIC WIRES MADE OF THERMOACTIVE SUPERELASTIC SHAPE MEMORY ALLOY AND 22 K GOLD TAKE SYZYGIUM CUMINI FRUIT JUICE ORALY? S.Madhumitha

CAN PEOPLE IMPLANTED WITH ORTHODONTIC WIRES MADE OF THERMOACTIVE SUPERELASTIC SHAPE MEMORY ALLOY AND 22 K GOLD TAKE SYZYGIUM CUMINI FRUIT JUICE ORALY? S.Madhumitha 1, V.Priyadharshini 1, A.Sheela 1, C.Aadhithya 1, Dr. M. Sangeetha 2, Dr. S. Rajendran 2 1. Department of Biomedical engineering, RVS School of engineering and Technology, Dindigul madhumitha1997@gmail – 624005, E-mail: [email protected] [email protected]

2. Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India, Email :[email protected] ABSTRACT Corrosion resistance of two orthodontic wires made of thermoactive superelastic shape memory alloy and 22 K gold in artificial saliva in the absence and presence of syzygium cumini extract has been evaluated by AC impedance spectra. It is observed that in the presence of artificial saliva containing 20 mL fruit extract, the corrosion resistance of thermoactive superelastic shape memory alloy decreases. Hence people implan implanted ted with orthodontic wires made of thermoactive superelastic shape memory alloy should avoid taking the fruit juice. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India.


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However interesting the corrosion resistance of 22 K gold increases in presence of artificial saliva containing 20 mL of fruit extract. Hence it implies that people implanted with orthodontic wire made of 22 K gold need not to hesitate to take the fruit juice orally. Keywords: Artificial Saliva, Orthodontic Wires, Thermoactive Superelastic Shape Memory Alloy, 22 K Gold, syzygium cumini 1. INTRODUCTION Our human civilization cannot exist without metals and yet corrosion is their Achilles heel. Corrosion process are responsible for numerous losses mainly in the industrial scope. Considerable efforts are made to find suitable compounds to be used as corrosion inhibitors in various corrosive media. Though many synthetic compounds showed good anticorrosive activity, most of them are highly toxic to both human beings and environment. Extracts of plant materials contain a wide variety of organic compounds. Most of them contain heteroatoms such as P, N, S, O. These atoms coordinate with the corroding metal atom (their ions), through their electrons. Hence protective films are formed on the metal surface and hence corrosion is prevented. They are eco friendly, bio degradable and available in plenty. Recently may researchers doing work on natural inhibitors. Several studies have been published on the use of natural products as corrosion inhibitors. Recently several juice extract are used as corrosion inhibitors for mild steel [1-4], garlic extract is used for aluminium metal [5], ginger [6] and extract of jamun seed for acid medium [7] have been used as corrosion inhibitors. The present work is undertaken to evaluate corrosion resistance of two orthodontic wires made of thermoactive superelastic shape memory alloy and 22 K gold in artificial saliva in the absence and presence of syzygium cumini extract by AC impedance spectra.



408


2. Methods and materials 2.1 Preparation of Artificial saliva solution Artificial saliva is prepared in laboratory and the composition of artificial saliva is as follows: KCl - 0.4 g/lit, NaCl - 0.4 g/lit, CaCl2.2H2O - 0.906 g/lit, NaH2PO4.2H2O -

0.690 g/lit,

Na2S.9H2O -0.005 g/lit, Urea – 1 g/lit. 2.2 Preparation of syzygium cumini extract An aqueous extract of syzygium cumini (naval fruit) was prepared by adding 10g of syzygium cumini , with distilled water and boiled the water for 15 mins filtering the suspending impurities, and making up to 100 ml. The extract was used as corrosion inhibitor in the present study. 2.3 AC impedance measurements A CHI 660A electrochemical impedance analyzer model was used to record AC impedance measurements. The cell set up was the same as that used for polarization measurements. The real part (Z’) and imaginary part (Z”) of the cell impedance were measured in ohms for various frequencies. The Rt (charge transfer resistance) and Cdl (double layer capacitance) values were calculated. 3. RESULTS AND DISCUSSION 3.1 Analysis of AC Impedance spectra AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface. If a protective film is formed on the metal surface, charge transfer resistance (Rt) increases; double layer capacitance value (Cdl) decreases. Impedance value increases [8-15]. The AC impedance spectra of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained from AC impedance spectra are shown in Fig.1.The AC impedance parameters namely charge transfer resistance (Rt) and double layer capacitance (Cdl) derived from Nyquist plots are given in Table 1. It is observed that when fruit extract is added to artificial saliva, the charge transfer resistance (Rt) decreases from 9695 ohm cm2 to 1709 ohm cm2 for (AS + 10 mL fruit Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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extract) and 9627 ohm cm2 for (AS + 20 mL fruit extract) respectively and the (Cdl ) increases

from 6.0856 x 10-10 F/ cm2 to 34.51 x 10-10 F/ cm2 and 6.128 x 10-10 F/ cm2 for (AS + 10 mL fruit extract) (AS + 20 mL fruit extract) respectively. All this observations lead to the conclusion that when we are adding fruit extract to artificial saliva, corrosion resistance of the thermoactive superelastic shape memory alloy is decreased and there is no formation of protective film on the metal surface. Hence people implanted with orthodontic wires made of thermoactive superelastic shape memory alloy should avoid taking the fruit juice.

Fig 1: AC impedance spectra of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract (Nyquist Plots) : (a) Artificial Saliva (AS) ; (b) syzygium cumini fruit extract (c) AS + 10 mL fruit extract (d) AS + 20 mL fruit extract Table .1 AC impedance parameters of thermoactive superelastic shape memory alloy immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained by AC impedance spectra. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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System AS Fruit extract AS + 10 mL fruit extract AS + 20 mL fruit extract

Rt ohm cm2 9695 3394

6.0856 x 10-10 17.383 x 10-10


1709

34.51 x 10-10

1.680

9627

6.128 x 10-10

1.265

Cdl F/ cm2

3.2 Analysis of AC Impedance spectra The AC impedance spectra of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained from AC impedance spectra are shown in Fig.2.The AC impedance parameters namely charge transfer resistance (Rt) and double layer capacitance (Cdl) derived from Nyquist plots are given in Table 2. It is observed that when fruit extract is added to artificial saliva, the charge transfer resistance (Rt) increases from 4262 ohm cm2 to 4657 ohm cm2 for (AS + 10 mL fruit extract) and 5587 ohm cm2 for (AS + 20 mL fruit extract) respectively and the (Cdl ) decreases from 1.384 x 10-9 F/ cm2 to 1.266 x 10-9 F/ cm2 and 1.056 x 10-9 F/ cm2 for (AS + 10 mL fruit extract) (AS + 20 mL fruit extract) respectively. These results lead to the conclusion that a protective film is formed on the metal surface. All these observations lead to the conclusion that in presence of fruit extract the corrosion resistance of 22 K in contact with artificial saliva, increases. Hence AC impedance spectra lead to the conclusion that people having orthodontic wires made of 22 K gold need not hesitate to take syzygium cumini fruit juice. The active ingredients of the juice have not corroded the orthodontic wires made of 22 K gold ; rather they have protected the wire by formation of protective film on the surface of the wires.



411


Fig 1: AC impedance spectra of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract (Nyquist Plots) : (a) Artificial Saliva (AS) ; (b) syzygium cumini fruit extract (c) AS + 10 mL fruit extract (d) AS + 20 mL fruit extract Table .2 AC impedance parameters of 22 K gold immersed in Artificial Saliva (AS) in the absence and presence of fruit extract, obtained by AC impedance spectra.

System AS Fruit extract AS + 10 mL fruit extract AS + 20 mL fruit extract

Rt ohm cm2 4262 6587

Cdl F/ cm2 1.384 x 10-9 0.895 x 10-9


4657

1.266 x 10-9

1.351

5587

1.056 x 10-9

1.361



412


4. Conclusion Results of the AC impedence study lead to the conclusion that  In artificial saliva alone, thermoactive superelastic shape memory alloy is more corrosion resistant than 22K gold.  In fruit juice alone 22 K gold is found to be more corrosion resistant than thermoactive superelastic shape memory alloy.  In presence of artificial saliva containing 10 mL of extract, 22 K gold is found to be more corrosion resistant than thermoactive superelastic shape memory alloy.  The increase in corrosion resistance of the orthodontic wire in presence of fruit extract may be due to the formation of protective film formed on the metal surface due to the adsorbtion of active principle of the ingrediants present in the fruit juice.  People implanted with orthodontic wire made of 22 K gold needs not to hesitate to take the fruit juice orally. 5. References 1. C.A.Loto, A.I.Mohammed, Loto, “Inhibition evaluation of mango juice extracts on the corrosion of mild steel in HCl”. Corrosion Prevention and Control 50(3), (2003), pp.107118. 2. C.A.Loto, A.I.Mohammed, “The effect of cashew juice extract on corrosion inhibition of mild steel in HCl”. Corrosion Prevention and Control 47(2), (2000), pp.50-56. 3. J.C.Da Rocha, J.A.da Cunha Ponciano Gomes, E.D Elia, “Corrosion inhibition of carbon steel in hydrochloric acid solution by fruit peel aqueous extracts”. Corrosion Science 52(7), (2010) pp.2341-2348. 4. P.C.Okafor, E.E.Ebenso, “Inhibitive action of Carica papaya extracts on the corrosion of mild steel in acidic media and their adsorption characterristics”. Pigment and Resin Technology 36(3), (2007), pp.134-140. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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5. S.L.Priya, A.Chitra, S.Rajenderan, K.Anuradha, “Corrosion behaviour of aluminium in rain water containing garlic extract”. Surface Engineering 21(3), (2005), pp.229-231. 6. A.Bouyanzer, B.Hammouti, “Naturally occurring ginger as corrosion inhibitor for steel in molar hydrochloric acid at 353 K”. Bulletin of Electrochemistry 20(2), (2004), pp.63-65. 7. Ambrish Singh, M. A. Quraishi, “The extract of Jamun (Syzygiumcumini) seed as green corrosion inhibitor for acid media”. Research on Chemical Intermediates 41 (3) , (2015), pp 2901–2914 8. R.Epshiba, A.Peter Pascal Regis and S.Rajendran, Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 1-11. 9. N. Kavitha and P. Manjula , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 31-38. 10. R. Nagalakshmi , L. Nagarajan , R.Joseph Rathish , S. Santhana Prabha , N. Vijaya , J. Jeyasundari and S. Rajendran , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 39-49. 11. J. Angelin Thangakani, S. Rajendran ,J. Sathiabama , R M Joany , R Joseph Rathis , S Santhana Prabha , Int. J. Nano. Corr. Sci. Engg. 1(1), (2014), pp 50-62. 12. A. Nithya , P.Shanthy, N.Vijaya, R.Joseph Rathish, S.Santhana Prabha, RM Joany and S. Rajendran, Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 1-11. 13. T.Gowrani , P.Manjula , Nirmala Baby, K.N.Manonmani, R.Sudha, T.Vennila, Int. J. Nano. Corr. Sci. Engg. 2(1), (2015), pp 12-21. 14. Namita K. Johar, K. Bhrara, R.Epshiba and G. Singh, Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 22-31. 15. A.Christy Catherine Mary, S.Rajendran, Hameed Al-Hashem, R.Joseph Rathish, T. Umasankareswari and J Jeyasundari Int. J. Nano Corr. Sci. Engg. 2(1), (2015), pp 42-50.



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Corrosion behaviour of carbon steel in isoelectric point and nearly neutral aqueous medium by L – arginine and zinc ion as a synergist S.Sulochana1

Corrosion behaviour of carbon steel in isoelectric point and nearly neutral aqueous medium by L – arginine and zinc ion as a synergist S.Sulochana1*, P.Revathi1, A.Sahaya Raja1, J. Sathiyabama1, V.Prathipa2 1PG& Research Department of Chemistry, G.T.N. Arts College, Dindigul, Tamilnadu, India 2Department of chemistry, PSNA College Engineering and Technology, Dindigul, Tamilnadu, India Abstract

The inhibitor system L - arginine- Zn2+ was investigated by weight loss method, Polarization study and AC impedance spectroscopy. A synergistic effect exists between L – arginine and Zn2+ system. The formulation consisting of L - arginine- Zn2+ offers maximum inhibition efficiency (IE). Polarization study reveals that this formulation functions as an anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. At isoelectric point, the IEs of L – arginine and also the L - arginine-Zn2+ systems are very low. In some cases there is acceleration of corrosion negative IEs. Keywords: Corrosion; Carbon steel; L – arginine; Polarization study; AC impedance spectra Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

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1. Introduction

Carbon steel is a metal alloy. It is a combination of two elements, iron and carbon. In which the carbon percentage is 0.12–2.0%. As the carbon percentage content rises, steel has the ability to become harder and stronger. Carbon steel finds a lot of application in industries. It gets rusted when it comes in contact with any aqueous medium. The use of inhibitors is one of the best methods for protecting metals against corrosion. Corrosion is a natural process, which converts a refined metal to a more stable form, such as its oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usually metals) by chemical and/or electrochemical reaction with their environment. Corrosion inhibitor is a substance which, when added to an environment in a small concentration, effectively reduces the corrosion rate of a metal exposed to that environment. There are three types of corrosion inhibitors: 1.Anodic inhibitors, 2.Cathodic inhibitors, 3.Mixed inhibitors. The majority of well –known inhibitors are organic compounds containing heteroatom, such as O, N, S and multiple bonds1. Most of the organic compounds are not only expensive but also toxic to both human beings and environments2 and therefore the use of hazardous chemical inhibitors is totally reduced because of environmental regulations. It is better to look for environmentally safe inhibitors. Many researchers investigated the inhibition effect of environment friendly inhibitors like amino acids on metal corrosion3-13. This is due to the fact that amino acids are non-toxic, biodegradable, relatively cheap, and completely soluble in aqueous media and produced with high purity at low cost. Various amino acids have been used to inhibit the corrosion of metals and alloys14-17.Eco–Friendly Inhibitor L–Cysteine–Zn2+ System to control corrosion of carbon steel in Aqueous Medium6. The corrosion of SS 316L has been inhibited by glycine, leucine, valine, and arginine7. Sivakumar et al have used L-Histidine to prevent Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

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corrosion on carbon steel8. Cystein, glycine, glutamic acid, and glutathione have been used as corrosion inhibitor to prevent the corrosion of copper in HCl9. Amino acid such as DL-Phenylalanine has been used to prevent corrosion of carbon steel10.The corrosion of brass in O2-free NaOH has been prevented by methionine11. Sahaya Raja et al have used Glycine along with Zn2+ to prevent corrosion of carbon steel in well water12. Prathipa et al was studied corrosion inhibition of carbon steel using green inhibitor (L-Alanine)18. Arginine - Zn2+ system has been used to inhibit corrosion of carbon steel13, 19. L – Alanine as inhibitor for carbon steel in well water was studied 20. 2. Material and Methods: Chosen inhibitor – L – arginine is shown in Fig – 1. Determination of corrosion rate - All the weight of the carbon steel specimens before and after corrosion was carried out using Shimadzu Balance-AY62.Corrosion rates were calculated using the following relationship. Corrosion Rate (mm/y) = [loss in weight (mg) X 1000 / surface area of the specimen (dm2) X period of the immersion (days)] X (0.0365/ ρ).Electrochemical and Impedance measurements - Potentiodynamic polarization studies and AC Impedance measurements are carried out using CHI electrochemical impedance analyzer (model 660A) All solutions were prepared using well water collected from N.S. Nagar, Dindigul, Tamil Nadu, India. The study was carried out at room temperature 303K. The chosen environmental well water and its some physicochemical parameters are pH- 8, Conductivity - 1677 µmhos/cm,TDS – 1200ppm,TH – 860ppm, Chloride – 490ppm


417


Fig.1.Structure of Arginine at different pH 3. Result and discussion 3.1 Analysis of the weight loss method Corrosion rates (CR) of carbon steel immersed in well water in the absence and presence of inhibitor (L - arginine) are given in Table 1.The inhibition efficiencies (IE) are also given these table. It is observed that L - arginine shows some inhibition efficiencies. 50 ppm of L - arginine has 48 percent IE, as the concentration of L - arginine increases the IE decreases. This is due to the fact that as the concentration of L – arginine increases, the protective film (probably iron L – arginine complex) formed on the metal surface goes into solution. That is, the system passes from passive region to active region. Similarly, for a given concentration of L - arginine the IE increases as the concentration of Zn2+ increases it is also observed that a synergistic effect exists between L - arginine and Zn2+. For example, 5 ppm of Zn2+ has 15 percent IE; 250 ppm of L - arginine has 34 percent IE. Interestingly their combination has a high IE, namely, 98 percent. In presence of Zn2+ more amount of L arginine is transported towards the metal surface. Thus the anodic reaction and cathodic reaction are controlled effectively. This accounts for the synergistic effect existing between Zn2+ and L - arginine. The IE of L – arginine -Zn2+ system at the isoelectric point of Arginine (pH=10.8) is given in Table 1. At isoelectric point, L – arginine exists as zwitter ion. At isoelectric Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

418


point, when an electric field is applied there is no movement of ions. Accordingly it is observed from Table 1, the IEs of L – arginine and also the L - arginine-Zn2+ systems are very low. In some cases there is acceleration of corrosion (negative IEs). Table.1: Corrosion rates (CR) of carbon steel immersed in well water in the presence and absence of inhibitor system at various concentrations and the inhibition efficiencies (IEs) obtained by weight loss method. At pH – 8 L - arginine ppm 0 0 50 100 150 200 250

Zn2+ (0 ppm) IE % CR (mm/y) -0.0874 ---

At pH – 10.8 Zn2+ (5 ppm) IE % CR (mm/y) ---

Zn2+ (0 ppm) IE % CR (mm/y) 0.0790 --

Zn2+ (5 ppm) IE % CR (mm/y) ---

15

0.0743

--

--

33

0.0529

48

0.0455

82

0.0157

22

0.0616

26

0.0584

46

0.0472

85

0.0131

17

0.0655

19

0.0639

40

0.0525

90

0.0087

13

0.0687

11

0.0703

39

0.0533

92

0.0069

7

0.0737

5

0.0750

34

0.0577

98

0.0017

2

0.0774

-4

0.0821

3.2 Analysis of Potentiodynamic Polarization study

Polarization study has been used to confirm the formation of protective film formed on the metal surface during corrosion inhibition process6,8,10,21,22. If a protective film is formed on the metal surface, the corrosion current value (Icorr) decreases. The potentiodynamic polarization curves of carbon steel immersed in well water in the absence and presence of inhibitors are shown in Fig-2. The corrosion parameters are given in Table 2. When carbon steel was immersed in well water the corrosion potential was -672 mV vs SCE. When L - arginine (250 ppm ) and Zn2+ (5 ppm) were added to the above Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

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system the corrosion potential shifted to -623 mV vs SCE. This suggests that a protective film is formed on the metal surface. Further the corrosion current decreases from 5.784 X -7

-7

10 A/cm2 to 5.111 X10 Thus polarization study confirms the formation of a protective film on the metal surface. At isoelectric point, when carbon steel was immersed in well water the corrosion potential was -647 mV vs SCE. When L – arginine (250 ppm) and Zn2+ (5 ppm) were added to the above system, the corrosion potential shifted to -660 mV vs SCE. The corrosion potential is shifted cathodic side (active site). It is observed that Icorr value increases, there is no protection of metal, the metal undergoes corrosion. This is in agreement with weight loss results. This is due to the fact that at isoelectric point (pH = 10.8) there is no migration of L arginine towards the metal surface. Therefore amount of L – arginine transported towards the metal surface is reduced. So, metal is not protected by L – arginine . Hence there is no IE at isoelectric point. Table 2: Corrosion parameters of carbon steel immersed in well water in the absence and presence of inhibitor system obtained from potentiodynamic polarization study At pH – 8 System

Well water Well water + L - arginine (250ppm)+ Zn2+ (5ppm)

At pH – 10.8

Tafel Results Ecorr mV Icorr A/cm2 vs SCE -7

-672

5.784 X 10

-623

5.111 X10

-7

Tafel Results Ecorr mV vs Icorr A/cm2 SCE -7

-647

6.702 X 10

-660

6.756 X10

-7


420


Fig 2: Polarization curves of carbon steel immersed in various test solutions a) Well water (Blank) ; b)Well water + L - arginine (250 ppm) + Zn2+ (5 ppm)

3.3 Analysis of AC Impedance spectra

AC impedance spectra (electro chemical impedance spectra) have been used to confirm the formation of protective film on the metal surface11,13,23,24. If a protective film is formed on the metal surface, charge transfer resistance (Rt) increases; double layer capacitance value (Cdl) decreases. The AC impedance spectra of carbon steel immersed in well water in the absence and presence of inhibitors (L - arginine-Zn2+) are shown in Fig-3 (Nyquist plot). The AC impedance parameters namely charge transfer resistance (Rt) and double layer capacitance (Cdl) derived from Nyquist plot are given in Table 3. It is observed that when the inhibitors (L - arginine (250 ppm) +Zn2+ (5 ppm)) are added the charge transfer resistance (Rt) increases from 1190 Ω cm2 to 16255 Ω cm2. The Cdl value decreases from -9

3.8755x10

-10

F/cm2 to 3.1572x10

F/cm2. These results lead to the conclusion that a

protective film is formed on the metal surface. At isoelectric point, when the inhibitors [L - arginine(250 ppm) + Zn2+ (5 ppm)] are added, the charge transfer resistance (Rt) decreases from 1550 Ω cm2 to 1520 Ω cm2 . Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

421

Corrosion behaviour of carbon steel in isoelectric point and nearly neutral aqueous medium by L – arginine and zinc ion as a synergist S.Sulochana1 -9

-9

The Cdl value increases from 3.3059 x10 F/cm2 to 3.3805 x10 F/cm2. When a protective film is not formed, charge transfer resistance (Rt) decreases and Cdl increases; the impedance value decreases, there is no protection of metal, the metal undergoes corrosion. This is in agreement with weight loss results. This is due to the fact that at isoelelctric point (pH=10.8) there is no migration of L – arginine towards the metal surface. Therefore amount of L – arginine transported towards the metal surface is reduced. So, metal is not protected by L – arginine. Hence there is no IE at isoelectric point. Table 3: Corrosion parameters of carbon steel immersed in well water in the absence and presence of inhibitor system obtained from AC impedance spectra. At pH – 8 System Rt Ω cm2 Well water

1190

Well water + 16255 L - arginine (250ppm)+ Zn2+ (5ppm)

At pH – 10.8

Nyquist plot Cdl F/cm2 -9

3.8755x10 -10

3.1572x10

Nyquist plot Rt Cdl 2 Ω cm F/cm2 -9

1550

3.3059 x10

1520

3.3805 x10

-9


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Fig 3: AC impedance spectra of carbon steel immersed in various test solutions (Nyquist plots) a) Well water (Blank) ; b)Well water + L - arginine (250 ppm) + Zn2+ (5 ppm)

4. Conclusion

The results of the weight - loss study show that the formulation consisting of 250 ppm L – arginine , 5 ppm of Zn2+ has 98% IE, in controlling corrosion of carbon steel in well water. A synergistic effect exists between Zn2+ and L – arginine system. Polarization study reveals that the formulation functions as anodic inhibitor controlling the anodic reaction predominantly and to some extent controls the cathodic reaction. AC impedance spectra reveal that a protective film is formed on the metal surface. At isoelectric point (pH=10.8) Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 415 - 427 Editors: Dr S Rajendran, A Christy Catherine Mary

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polarization study and AC impedance spectra revealed that there is no synergistic effect exists between Zn2+ and L – arginine and indicated that there is no protection of metal, the metal undergoes corrosion 5. Acknowledgement

The authors are thankful to their respective management, Principal, G.T.N.Arts College, Dindigul, Tamil Nadu, India for providing the required facilities for completion of the work. 6. References 1. P. Bothi Raja, M.G. Sethuraman,2008, Inhibitive effect of black pepper extract on the sulphuric acid corrosion of mild steel, Mater. Lett. 62, 2977 2. A.Y. El-Etre, 2006,Khillah extract as inhibitor for acid corrosion of SX 316 steel, Appl. Surf. Sci. 252, 8521 3. Ashassi-Sorkhabi, M.R. Majidi and K. Seyyedi, 2004,Investigation of inhibition effect of some amino acids against steel corrosion in HCl solution, Appl. Surf. Sci. 225, 176 4. Z. Ghasemi and A. Tizpar, 2006 The inhibition effect of some amino acids towards Pb-Sb-Se-As alloy corrosion in sulfuric acid solution, Appl. Surf. Sci. 252, 3667 5. N. O. Eddy, U. J. Ibok, and B. I. Ita, 2011,QSAR and quantum chemical studies on the inhibition potentials of some amino acids for the corrosion of mild steel in H2SO4, J. Comp. Methods. Sci. Engg. 11, 25 6. A.Sahaya Raja, J. Sathiyabama , R. Venkatesan , V. Prathipa, 2014,Corrosion Control of Carbon Steel by Eco–Friendly Inhibitor L–Cysteine–Zn2+ System in Aqueous Medium, J. Chem. Biol. Phy. Sci. 4, 3182


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7. N. A. Abdel Ghany, A. E. El-Shenawy, and W. A. M. Hussien, 2011,The inhibitive effect of some amino acids on the corrosion behaviour of 316L stainless steel in sulfuric acid solution, Modern Appl. Sci. 5, 19 8. S.Sivakumar, A.Sahaya Raja, J.Sathiyabama, V.Prathipa, 2014, Spectroscopic methods used for analyzing protective film formed by L-Histidine on carbon steel, Int. J. Pharm. Drug Anal. 2, 601 9. D.-Q. Zhang, B. Xie, L.-X. Gao, Q.-R. Cai, H. G. Joo, and K. Y. Lee,2011, Intramolecular synergistic effect of glutamic acid, cysteine and glycine against copper corrosion in hydrochloric acid solution, Thin Solid Films., 520, 356 10. A. Sahaya Raja, S. Rajendran, and P. Satyabama,2013, Inhibition of Corrosion of Carbon Steel in Well Water by DL-Phenylalanine-Zn2+ System, J. Chem. 2013, 1 11. A.Sahaya Raja, S. Rajendran, J. Nagalakshmi, Angelin Thangakani and M. Pandiarajan,2012, Eco-Friendly Inhibitor Glycine-Zn2+ System Controlling Corrosion of Carbon Steel in Well Water, Euro. Chem. Bull. 1, 130 12. J. Wu, Q. Wang, S. Zhang, and L. Yin,. Wu, Q. Wang, S. Zhang, and L. Yin, 2011,Methionine as corrosion inhibitor of brass in O2-free 1M NaOH solution, Adv. Mat. Res. 308, 241 13. Anthony Samy Sahaya Raja and Susai Rajendran, 2012,Inhibition of corrosion of carbon steel in well water by arginine - Zn2+ system, J. Electrochem. Sci. Engg. 2, 91 14. A.Sahaya

Raja,

P.Angel,

R.Sonisheeba,

J.Thomas

Paul

raj,

S.Sivakumar,

R.Venkatesan, J.Sathiyabama, 2014,Corrosion Control by Green Solution – An Overview, International Journal of Advanced research in Chemical Science (IJARCS).,1, 10


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15. A.Sahaya Raja, R.Venkatesan, R.Sonisheeba, J.Thomas Paul raj, S.Sivakumar , P.Angel, J.Sathiyabama,2014, Corrosion Inhibition by Cysteine– An Overview, International Journal of Advanced research in Chemical Science(IJARCS)., 1, 101 16. A.Sahaya Raja, S. Rajendran, J.Sathiyabama and P. Angel,2014, Corrosion Control by Aminoacetic acid (Glycine) – An Overview, International Journal of Innovative research in Science, Engineering and Technology., 3, 11455 17. V.Prathipa, A.Sahaya Raja, 2015, A Review on the Assessment of Amino Acids Used As Corrosion Inhibitor of Metals and Alloys, J. Chem. Bio. Phy. Sci., 5, 1585 18. V.Prathipa, A. Sahaya Raja, S. Rajendran,2015, Electrochemical study and spectroscopic methods used for analyzing protective film formed by L-alanine on carbon steel in well water: A green approach, J. Adv. Chem. Sci., 1, 59 19. A.Sahaya Raja, S.Rajendran , J.Sathiyabama ,T.S.Muthumegala, A.Krishnaveni, N.Palaniswamy, P. Prabhakar,2011, Corrosion Inhibition by Arginine – Zn2+ system, Zastita Materijala., 52, 101 20. A.Sahaya Raja, N.Rajendran, V.Prathipa, S. Rajendran,2015, Nano analyses of protective film formed by L-alanine-zinc ion system onto carbon steel, J. Adv. Chem. Sci., 1 , 78 21. P.Angel , A. Sahaya Raja , J. Sathiyabama and V. Prathipa,2014, Corrosion inhibition of Vitex Negundo Extract as a green corrosion inhibitor for carbon steel in well water, International

Journal of Chemical Studies., 2, 31

22. J.ThomasPaulraj , A.Sahaya Raja , J.Sathiyabama , V.Prathipa,2014, A Study of Acalypha Indica Extract as a Novel Green Inhibitor for Carbon Steel in Aqueous Medium International Journal of Green and Herbal Chemistry., 3 , 1033


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23. R.Soni Sheeba, A Sahaya Raja, J.Sathiyabama and V.Prathipa,2014, Green approach to corrosion inhibition of carbon steel by the extract of Polyalthia Longifolia, Journal of Applicable chemistry,3, 2055 24. A.Sahaya Raja, Corrosion inhibition by Amino Acids, 2011, Ph.D.thesis, PG and Research department of chemistry, G.T.N. Arts college, Affiliated to Madurai Kamaraj University



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Cobalt Complex of 8-hydroxyquinoline derivative as potential Corrosion Inhibitor for Mild steel in aqueous Sodium Chloride solution S.S.Syed Abuthahir

COBALT COMPLEX OF 8-HYDROXYQUINOLINE DERIVATIVE AS POTENTIAL CORROSION INHIBITOR FOR MILD STEEL IN AQUEOUS SODIUM CHLORIDE SOLUTION S. S. Syed Abuthahir[a], A. Jamal Abdul Nasser[a], M.Muhammed Azar[a], K.Muhammed Rashid [a], S. Rajendran[b] [a] Post Graduate & Research Department of Chemistry Jamal Mohamed College (Autonomous), Tiruchirappalli 620 020, India. Email: [email protected], [email protected] [b] Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India, Email :[email protected] Abstract The effect of Cobalt complex of 1-(8-hydroxy quinolin-2yl-methyl) urea (Co-HUF) on the corrosion inhibition of mild steel has been investigated in aqueous sodium chloride solution. Result showed that the corrosion inhibition efficiency offered by 50 ppm of Co-HUF is 84 %. The corrosion resistance was observed because of the formation of more stable and compact Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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protective film on the mild steel surface. Electrochemical Impedance spectra reveal that the protective film formed on the mild steel surface. The surface of the samples exposed to the inhibited solutions was analyzed using EDAXs. Co-HUF has the ability to prevent the growth of certain microorganisms. Keywords: Transition metal complex, Corrosion inhibition, Mild Steel, EIS, EDAXs and Biocidal Activity. 1. Introduction Deterioration of materials from corrosion is still a challenging problem and a field of active interest for researchers and engineers. Inhibition is a keyword in the case of corrosion prevention by changing chemistry of corrosive media. Many industrial divisions such as acid cleaning bath, water cooling system, various refinery units, pipelines, chemical operations, steam generators, ballest tanks, oil and gas production units are involved with inhibitors due to high corrosion rate occur in these specific parts. Because of the wide applications, one could obviously obtain special importance of inhibitors in various industries. So many researchers are trying to introduce new organic compounds containing hetero atoms like nitrogen, oxygen and sulphur which are more effective and cost effective with easy access. It is believed that inhibitors efficiency basically refers to their molecular structure. Existence of unique atoms like nitrogen, sulphur and oxygen in heterocyclic compounds has been widely reported as an effective parameter in improvement of inhibitors efficiency. The structure and lone pair of electrons in the hetero atoms are important characteristics that determine the adsorption mechanism of these molecules on a metallic surface. Generally organic inhibitor molecules may physically or chemically adsorb on a corroding metal. In any case adsorption is general over the metal surface and the resultant adsorbed layer functions as a barrier which isolates the exposed metal from further deterioration. In neutral aqueous solutions containing chloride ions are extensively used for many purpose in various types of industries to clean heat exchanging apparatus to remove Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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deposits, in pickling operations for scale removed and for improvement of heat transfer efficiency of corrosion inhibition for the mild steel immersed in neutral media [1-4]. Metal complexes are widely used as catalyst of chemical reactions, e.g. oxidative dehydrogenation (ODH) of ethane and epoxidation of geraniol [5-7] and as stabilizer or precursor in sol-gel processes [8-10]. the effect of different concentration of the inhibitor on the corrosion behavior of mild steel has been studied in an aqueous solution containing 60 ppm of Cl-. The inhibition effect of acetylacetonates in some media has been discussed by the authors. Having good adsorption properties acetylacetonate complexes of Zinc(II), Magnese(II), Cobalt(II) and Copper(II) are shown to reduce the corrosion rate of mild steel in acid media [11-14]. The present work intends to evaluate the corrosion inhibitive effect of Cobalt Complex of 1-(8hydroxy quinolin-2yl-methyl) urea with different concentration on the mild steel immersed in aqueous solution containing 60 ppm of Cl- solution electrochemical impedance spectra as well as surface analysis, EDAX. This work is focused on the evaluation of corrosion inhibition of Cobalt Complex of 1-(8-hydroxy quinolin-2yl-methyl) urea in neutral solution. Co-HUF has the ability to prevent the growth of certain microorganisms such as E.Coli, Streptococcus, Pseudomonas and Entrobacter. 2. Materials and Methods 2.1 Metal specimens Mild steel specimens; (0.028% S, 0.066% P, 0.37 % Mn, 0.12 % C and the rest iron ) of dimensions 1.0 cm ×4.0×0.2 cm were polished to mirrors finish and degreased with acetone. 2.2 AC impedance spectra The instrument used for polarization study was also used for AC impedance spectra. The cell set up was the same as that was used for polarization measurements. The real part (Z’) and the imaginary part (Z’’) of the cell impedance were measured in ohms at various frequencies. AC Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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impedance spectra were recorded with initials E (v) =0V, high frequency limit was 1×105 Hz, low frequency limit was 1 Hz, amplitude =0.005V and quiet time tq=2 s. The values of charge transfer resistance Rt and the double layer capacitance Cdl were calculated. Cdl = ½ πRtfmax Where fmax is maximum frequency. 2.3 Surface Characterization studies The mid steel specimens were immersed in various test solution for a period of one day. After one day the specimens were taken out and dried. The nature of the film formed on the surface of the metal specimen was analyzed by various surface analysis techniques. 2.4 Energy Dispersive Analysis of X-rays (EDAXs) The mild steel specimen immersed in blank and in the inhibitor solution for a period of one day was removed, dried and observed in an Energy Dispersive Analysis of X-rays (EDAXs) to examine the elements presents on the metal surface. The elements present on the metal surface were examined using Bruker computer controlled Energy Dispersive Analysis of X-rays (Brucker, Nano, GMBH, Germany). 2.5 Bacterial Enumeration Bacterial cell are count based on their colony forming unit (CFU) by standard plate count. The protocols are as follows. Label the plate 10-2, 10-4, 10-6 and 10-8 at the bottom of plate and one plate as a blank or control. Using aseptic technique transfer 1ml of four different cultures to 99ml of sterile saline blank. A test tube labelled 10-2 and the dilution is proceeded by taking 1ml from 10-2 test tube to the next 99ml sterile saline blank labeled as to the next 99ml sterile saline blank labeled as 10-4 and proceed until 10-8. Shake all the test tubes for equal distribution of bacteria. Transfer 1ml of the sample into each of the labelled plates 10-2 to 10-8 correspondingly. Containing agar medium all the plates are immersed and incubate at 370C for 24 hours. After the


431


incubation, select the plate contains 30 to 300 colonies and counts the colonies. The number of CFU are calculated as CFUs/dilution × amount plated = No.of bacterial cell / ml. 3. RESULTS AND DISCUSSION 3.1 Analysis of AC impedance spectra AC impedance spectra [electrochemical impedance spectra] have been used to confirm the formation of protective film on the metal surface [15-18]. The AC impedance spectra of mild steel immersed in aqueous solution containing 60ppm of Cl- in the absence and presence of inhibitors are shown in Fig.1( Nyquist plots) and Fig.2 (Bode plots). The impedance parameters namely charge transfer resistance (Rt) double layer capacitance (Cdl) and impedance lg(z/ohm) are given in Table-1. If a protective film is formed on the metal surface, Rt value increases and the Cdl value decreases. . Table 1. The AC impedance spectra of mild steel immersed in aqueous solution containing 60ppm of Cl- in the absence and presence of Co-HUF inhibitor system.

Systems

Rt Ω cm2

Cdl F cm-2

Impedance, Log ( Z ohm-1)

60 ppm Cl-

20.19

5.235 × 10-5

0.973

3.519 × 10-6

2.022

60 ppm

Cl- + 50 300.32

ppm Co- HUF


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When mild steel is immersed in aqueous solution containing 60ppm of Cl-, Rt value is 20.19 Ω cm2 and Cdl value is 5.235 × 10-5 F cm-2. When Co-HUF are added to the aqueous solution containing 60ppm of Cl- Rt value increases from 20.19 Ω cm2 to 300.32 Ω cm2 and the Cdl value decreases from 5.235 × 10-5 F cm-2 to 3.519 × 10-6 F cm-2 . The impedance value increases from 0.973 to 2.022. This account for the high inhibition efficiency of Co-HUF system and a protective film is formed on the metal surface. This is also supported by the fact that for the inhibitor system the phase angle increases from 47.88 to 62.38 o (Fig.2).

Figure 1.AC impedance spectra (Nyquist plots) of mild steel immersed in various test solutions a) aqueous solution containing 60ppm of Cl-. b) aqueous solution containing 60ppm Cl- + 50 ppm Co-HUF


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Figure 2a. AC impedance spectra (Bode Plot) of mild steel immersed in aqueous solution containing 60ppm of Cl-

Figure 2b. AC impedance spectra (Bode Plot) of mild steel immersed in solution containing 60ppm of Cl- + 50ppm of Co- HUF Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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3.2 Energy Dispersive Analysis of X-Rays (EDAXs) The EDAX survey spectra were used to determine the elements present on the mild steel surface before and after exposure to the inhibitor solution [19-22]. The objective of this section was to confirm the results obtained from chemical and electrochemical measurements that a protective surface film of inhibitor is formed on the mild steel surface. To achieve this, EDAX examinations of the mild steel surface were performed in the absence and presence of inhibitors system [19-22]. The EDAX spectrum of mild steel is shown in Fig 3 (a) and EDAX spectrum of mild steel immersed in an aqueous solution containing 60 ppm of Cl- is shown in Fig.3 (b). They show the characteristic peaks of some of the elements constituting the mild steel sample. The EDAX spectrum of mild steel immersed in an aqueous solution containing 60 ppm of Cl- and 50 ppm of Co-HUF is shown in Fig.3 (c). It shows the additional line characteristic for the existence of Co, the intensity of O signals is reduced and the intensity of Fe signal is increased. The appearance of Fe signal and this enhancement of O signal are due to the presence of inhibitor. These data show that mild steel surface is covered with the N, O, C, Fe and Co atoms. This layer is undoubtedly due to the inhibitor system. The Fe, Co signal and this high contribution of O and C is not present on the mild steel surface exposed in an aqueous solution containing 60 ppm of Cl-. Fig.3.(c) shows that the Fe peaks observed in the presence of inhibitor are considerably suppressed relative to these observed in an aqueous solution containing 60 ppm of Cl- (blank solution). The suppression of the Fe peaks occurs because of the overlying inhibitor film. This observation indicates the existence of an adsorbed layer of inhibitor that protects steel against corrosion. These results suggest that O, N and C atoms of Co-HUF has coordinated with Fe2+, Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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resulting in the formation of Fe2+-HUF complex on the cathodic sites of mild steel surface and presence of Co atoms are precipitated as Co(OH)2 on the anodic sites of mild steel surface. cps/eV

10

8

6 C

Mn O Fe

Mn

Fe

4

2

0 1

2

3

4 keV

5

6

7

8

Fig.3 (a) EDAX spectrum of Mild steel specimen (control)


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Fig.3(b) EDAX spectrum of Mild steel sample after immersion in an aqueous solution containing 60 ppm of Cl- (blank)

Fig.3 (c ) EDAX spectrum of Mild steel sample after immersion in an aqueous solution Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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containing 60 ppm of Cl- + 50 ppm of Co-HUF 3.3 Bacterial Enumeration count The results of bacterial enumeration count [23-26] of the aqueous solution containing 60ppm of Cl- and 60ppm of Cl- with Co-HUF inhibitor are presented in Table 2. The aqueous solution containing 60ppm of Cl- without inhibitor shows more bacterial count against the growth of pathogenic bacteria strains such as E.Coli, Streptococcus, Pseudomonas and Entrobacter. The aqueous solution containing 60ppm of Cl- with inhibitor Co-HUF shows less bacterial count against the growth of pathogenic bacteria strains such as E.Coli, Strptococcus, Pseudomonas and Entrobacter. A good result was obtained when addition of Co-HUF inhibitor to the corrosive media. Table 2. Colonies forming unit (CFU) of mild steel in aqueous solution containing 60 ppm of Cl- in the absence and presence of Co-HUF inhibitor obtained by bacterial enumeration count method. Systems

60 ppm Cl-

Colonies Forming Unit (per ml) E.Coli

Streptococcus

Pseudomonas

Entrobacter

140 × 10 6

146 × 10 6

130 × 10 6

127 × 10 6

55 × 10 6

57 × 10 6

63 × 10 6

60 ppm Cl- + 54 × 10 6 50 ppm CoHUF


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4. CONCLUSIONS The results show that the formulation consisting of 60 ppm of Cl- and 50 ppm of Co-HUF has 84% inhibition efficiency in controlling corrosion of mild steel. AC impedance spectra reveal that a protective film is formed on the mild steel surface. EDAX spectra confirm the presence of a protective film on the mild steel surface. The bacterial enumeration has been reduced by the addition of Co-HUF inhibitor to the corrosive media. 5. ACKNOWLEDGEMENT The authors are thankful to their management of Jamal Mohamed College (Autonomous), Tiruchirappalli-20, Tamilnadu, India. 6. REFERENCES [1] Migahed MA, Abdul Raheim AM, Atta AM, Brostow W, Synthesis and evaluation of a new water soluble corrosion inhibitor from recycled poly (ethylene terphethalate). Materials Chemsitry and Physics., 195, (2010), 3590-3596.

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P.Cicmanec, P.Knotek, Oxidative dehydrogenation of ethane over vanadium supported on mesoporous materials of M41S family, Appl.Catal.A Vol.342, pp.99-106, 2008. [6] C.Pereira, A. Rosa Silva, A.Paula Carvalho, J. Pires, C. Freire, Vanadyl acetylacetonate anchored onto amine-functionalised clays and catalytic activity in the epoxidation of geraniol, J. Mol. Catal. A,Vol. 283, pp. 5-14, 2008. [7] C. Pereira, S. Patricio, A.Rosa Silva, A.L. Magalhaes, A.Paula Carvahlo, J.Pires, Cristina Freire, Copper acetylacetonate anchored onto amine-funtionalised clays, J. Colloid interf. Sci.Vol. 316, pp. 570-579, 2007. [8] S. Fujihara, Sol-gel processing of fluoride and oxyfluoride materials, in:H. Kozuka (Ed.), Handbook of Sol-Gel Science and Technology: Volume 1- Sol-Gel Processing, Kluwer Academic Publoshers, pp. 219, 2005. [9] M. Cernea, O.Monnereau, P.Llewellyn, L. Tortet, C. Galassi, Sol-Gel synthesis and characterization of Ce doped- BaTiO3, J. Eur.Ceram.Soc.Vol. 26, pp.3241-3246,2006. [10] S.Tangwiwat, S.J.Milne, Barium titanate sols prepared by a diol – based sol-gel route, J.Non-Cryst. Solids, Vol. 351, pp. 976-980, 2005. [11] Ghanbari A, Attar MM, Mahdavian M, Prog.Color Colorants Coat. 2, (2009), 115-122. [12] Mahdavian M, Attar MM, Corros.Sci, 51 (2009), 409-414. [13] Mahdavian M, Attar MM, Prog.Org.Coat, 66 (2009) 137-140. [14] Naderi R, Mahdavian M, Attar MM, Electrochim.Acta 54, (2009), 6892-6895. [15] Sathiyabama, J., Rajendran, S., Arockia Selvi, J., Jeyasundari, J., Open Corrs. J., 2009, 2, 84. [16] Shyamala Devi, B., Rajendran, S., Eur. Chem.Bull., 2012, 1, 150. [17] Syed Abuthahir S.S., Jamal Abdul Nasser., Rajendran S., Inhibition effect of copper complex of 1-(8-Hydroxy quinolin-2yl-methyl) thiourea on the corrosion of mild steel in Sodium Chloride solution., The open.Mater. Sci.J. 8, (2014), 71-80. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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[18] Rajendran, S., Anuradha, K., Kavipriya, K., Krishnaveni, A., Andelin Thangakani, J., Eur.Chem.Bull., 2012, 1, 503. [19] Amin M A., Abd El-Rehim S S., El-Sherbini E F F., Bayoumi R S, “The inhibition of low carbon steel corrosion in hydrochloric acid solutions by succinic acid. Part I. Weight loss, polarization, EIS, PZC, EDX and SEM studies,” Electrochimica Acta, vol.52, no. 11, pp. 3588-3600, 2007. [20] Amin M A., Abd El-Rehim S S.,Abdel- Fatah, “Electrochemical frequency modulation and inductively coupled plasma atomic emission spectroscopy methods for monitoring corrosion rates and inhibition of low alloy steel corrosion in HCl solutions and a test for validity of the Tafel extrplotation method,” Corrosion Science, Vol. 51, no. 4, pp. 882-894, 2009. [21] Rahim S S A., Hazzazi O A., Amin M A., Khelad K F., “On the corrosion inhibition of low carbon steel in concentrated sulphuric acid solutions. Part I: chemical and electrochemical (AC and DC) studies,” Corrosion Science, Vol. 50, no. 8, pp.2258-2271, 2008. [22] Migahed M A., Azzam E M S., Morsy S M J., “Electrochemical behavior of carbon steel in acid chloride solution in the presence of dodecyl cysteine hydrochloride self-assembled on gold nanoparticles,” Corrosion Science, Vol. 51, no, 8, pp. 1636-1644, 2009. [23] Jackie Reynolds/Mark Farinha., Richland College, (2005). [24] Maruthamuthu S., Ponmariappan S., Indira K.R., Rengaswamy N.S and Subramanian A., Bull.Electrochem., 166 (2000) 209. [25] Atia A.A and Saleh M.M, J.Appl.Electrochem., 33 (2003) 171. [26] Syed Abuthahir S S., Jamal Abdul Nasser A., Rajendran S, Vijaya K., Electrochemical study of the corrosion behavior of Mild steel with Zinc Complex of 1-(8-Hydroxy quinolin2yl-methyl) thiourea as Inhibitor in Sodium Chloride solution., J.Appl.Chem.Sci.Int., 5(3), (2016), 134-146. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 428 - 442 Editors: Dr S Rajendran, A Christy Catherine Mary

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DECOLOURISATION OF DYES OF TEXTILE INDUSTRIES BY BIOCHEMICAL METHODS T. Marimuthu

DECOLOURISATION OF DYES OF TEXTILE INDUSTRIES BY BIOCHEMICAL METHODS T. Marimuthu1*, S.Rajendran2, 1Research and Development Centre, Bharathiar University, Coimbatore,Tamil Nadu, India. CELLNO :9942255402

email:[email protected]

Department of Chemistry, St.Antony’s college of arts and sciences for women, Dindigul, Tamilnadu, India, Email :[email protected] Abstact A variety of synthetic dyestuffs were released from the textile industry ry and made a threat to environmental safety. Azo dyes account for the majority of all dyestuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Existing effluent treatment procedures are unable to remove various dyes completely from effluents because of their color fastness, stability and resistance to degradation. Bacterial decolorization orization and degradation of dyes under certain environmental conditions. conditions The method of treatment, as these are inexpensive, eco-friendly eco and can be applied to wide range of such dyes. This study mainly focuses on the different of bacterial decolorization processes and find a solution to decolorization of dyes and dye effluents. Key words :dye dye decolorization ,bacterial decolorization,dye effluent,

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 443-453 Editors: Dr S Rajendran, A Christy Catherine Mary

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1.INTRODUCTION BACTERIA BIODEGRADATION Efforts to isolate bacterial cultures [1-9]capable of degrading azo dyes started in the 1970s with reports of a bacillus subtilis (Horitsu et al., 1977), followed by numerous bacteria pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders( Yu et al, 2001); Chang et al(2004) used the extracellular metabolites of a dye-decolorizing strain, Escherichia coli strain NO3, as a biostimulator to entice E. coli strain NO3 into a beneficial mode of metabolism for an conomically feasible colorization.To design technical decolorization processes of textile wastewater treatment with sulfide produced by reducing bacteria (SRB) was designed to decolorize textile wastewater treatment with sulfide(Yoo, 2002) .In general, the wastewater from textile industry contains many various dyes. To gain a widespread reception, the azo-degrading bacteria should exhibit decolorizing ability for a wide range of dyes, aeromonas hydrophila was selecte from six bacterial strains with the capability of degrading textile dyes (Chen et al, 2003). 2.MATERIALS AND METHODS The present study has been carried out to find the suitable bioremediation measures of textile dye effluent by using Biological and chemical agent. SAMPLE COLLECTION The dye effluent was collected from the Balammalpuran in Karur. The samples were collected by using sterile sample bottles and transported to the laboratory within 24 hrs of collection. The collected samples were stored at low temperature for further analysis. 2.1.ENUMERATION OF TOTAL MICROBES IN THE DYE EFFLUENT SAMPLE Total microbial counts in the dye effluent sample serially diluted (10ˉ¹to 10ˉ9). One ml from the dilution 10-3 was plated in Nutrient agar plates, using spread plate method and incubated at 37oC for 24 hrs for bacterial counts and PDA agar for fungal counts incubated at 28⁰C for 48 hrs. Colonies on the plates were counted by using colony counter.


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The Bacterial cultures were isolated and identified by pure culture and Biochemical methods. Bacterial culture isolated from dye effluent sample, dilution 0.1ml of sample was inoculated on Nutrient Agar plates and kept for incubation at 37oC for 24 hrs. broth and were incubated at 370 C for three days and 3 ml of alpha napthol was added followed by 1 ml of 40% KOH. It was mixed well and allowed to stand for 30 min. The results were interpreted based on the change of colour to pink. 2.2 ASSAY OF DECOLORIZATION ACTIVITY The bacterial strains (Bacillus, Pseudomonas, Acineto bacter, Legionella,Staphylococcus) and were grown on PDA agar plates and were streaked on plates containing dyes in media. The plates contained MM2 – Carbon, MM2 – Nitrogen, MM2 – Nitrogen – Carbon. Decolorization of the dye was visually observed for the extent of zone clearing on the plates.The extent of dye decolorization by the microbial cultures in broth was determined by spectrophotometer at the maximum absorbance of the respective dyes in the cell free extracts. The percentage of dye decolorization by the cells was done using the modified method of Yatome et al., (1991). Cultures were grown in 50 ml of broth for overnight at 37o C and 80 rpm to an OD of 1.00 at 600nm. The cultures were centrifuged at 10,000 rpm for 10 min. and washed twice with sterile saline (0.85%) and resuspended in 10 ml of saline solution. 0.1ml of the inoculum was added to the broth containing dye and incubated at 37°C, 85 – 110 rpm for 24 hr. The supernatant was collected after centrifugation for absorbance measurement at respective wavelengths. The percentage decolorization was calculated as follows: % age Decolorization = Initial O.D - Final O.D X100 Initial O.D 2.3. ANALYSING OF PHYSICO-CHEMICAL PARAMETERS OF THE DYE EFFLUENT SAMPLE The dye effluent sample was used for various Physico-chemical analysis viz., colour of the sample, Odour by direct smelling of the sample, Standard thermometer was used for temperature measurements, The pH of the sample was determined by pH meter.


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ADMI color was determined with a Spectrophotometer in accordance with the ADMI Tristimulus method 2120 D detailed in Standard Methods (1998). The spectrophotometer was calibrated before each use with standard platinum cobalt color solutions of 100, 200, 300, 400, and 500 ADMI color units. (Edwards, 2000). Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) were analyzed.

2.4 .BIOLOGICAL OXYGEN DEMAND (BOD) Adjust the pH of water sample to neutrality using 1N acid or 1N alkaline solutions. Fill the water sample in 6 BOD bottles without bubbling. Add 1 ml of Allyl thiourea to each bottle. Determine dissolved oxygen content in 3 of the 6 BOD bottles by titration method. Take the mean of the 3 readings (D1). Incubate the rest of 3 BOD bottles at 27ºC in a BOD incubator for 3 days. Estimate the oxygen concentration in all the 3 incubated samples. Take the mean of 3 readings (D2). Calculate the BOD of water in mg/l by using the following formula BOD (mg/l) = D1-D2 ,Where, D1

=

Initial dissolved oxygen in the sample (mg/l)

D2

=

Dissolved oxygen in the water sample (mg/l) after 3 days of incubation.

2.5.CHEMICAL OXYGEN DEMAND (COD) Take three , 100 ml conical flasks and pour 50 ml of water sample in each ( i.e., in triplicate). Simultaneously run distilled water blank standards (also in triplicate). Add 5 ml of potassium dichromate solution in each of the 6 flasks. Keep the flasks in water bath at 100ºC for 1 hour. Allow the samples to cool for 10 minutes. Add 5 ml potassium iodide solution in each flask. Add 10 ml of H2SO4 in each flask. Titrate the contents of each flask with 0.1 M of sodium thiosulphate solution until the appearance of pale yellow colour. Add 1 ml of starch solution to each flask (solution turns blue colour). Titrate the again with 0.1 M sodium thiosulphate until the blue colour disappears completely. Find out the COD (mg/l) of the water sample by using the following formula


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8*C*(Vв-VA)*1000 COD of the sample (mg/l) =

-------------------------S

Where, C

=

Concentration of titrant (0.l M)

Vв

=

Volume of titrant used for sample (ml)

VA

=

Volume of titrant used for blank (ml)

S

=

Volume of sample taken (ml)

2.6 .DEGRADATION ANALYZING FOR BACTERIA The isolated Bacterial samples Bacillus sp, Pseudomonas sp, Acineto bacter, Legionella and Staphylococcus was checked for the extent of dye degradation both in solid media plates as well as in liquid media.

All the isolates gave maximum degradation. Visual degradation

indicated that degradation was higher in case of broth as compared to minimal media. The overnight broth cultures (Bacillus sp, Pseudomonas sp, Acineto bacter, Legionella and Staphylococcus) with crude oil were centrifuged and resuspended in 10 ml of saline solution and 0.1ml of the inoculum was added to the broth containing crude oil and incubated at 37°C, 85 – 110 rpm for 24 hr. The supernatant was collected after centrifugation for absorbance measurement at 650 nm wavelengths. Among the five isolated bacterial strains, Pseudomonas showed higher degradation than Bacillus. The percentage degradation was calculated and given in Table-1 TABLE – 1 BACTERIAL DECOLORIZATION OF DYE EFFLUENT S.

BACTERIAL

NO

CULTURES

1

Bacillus sp

2

Pseudomonas sp

O.D BEFORE

O.D AFTER

DECORIZATION DECORIZATION

PERCENTAGE OF DEGRADATION (%)

0.34

0.12

65

0.34

0.09

73


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3

Acineto bacter

0.34

0.16

52

4

Legionella

0.34

0.19

45

0.34

0.14

58

Staphylococcus

5

% OF DECOLORIZATION

% OF Decolorization 80 70 60 50 40 30 20 10 0

% OF Decolorization

BACERIAL STRAIN

Fig -1 Bacterial Decolorization


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After inoculation of isolated microorganisms, the physico-chemical physico chemical parameters were analyzed for 2 weeks intervals.

Table -2 COD Removal by bacterial strain

COD mg per litre S.NO

1 2

Bacterial strain

Bacillus sp Pseudomonas sp

%OF COD

FIRST

3

6

9

12

DAY

DAYS

DAYS

DAYS

DAYS

938

872

801

743

688

26.65

938

863

737

624

502

46.48

REMOVAL AFTER 12 DAYS

Acineto bacter

938

789

671

409

374

60.12

4

Legionella

938

857

789

737

645

31.23

5

Staphylococcus

938

865

798

714

632

53.94

5OF COD REMOVAL

3

70 60 50 40 30 20 10 0

% OF COD Removal by bacterial strain

BACERIAL STRAIN

Fig -2 2 COD Removal by bacterial strain Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 443-453 Editors: Dr S Rajendran, A Christy Catherine Mary

449


Table -3 BOD Removal by Baterial strain BOD mg perlitre S.NO

Bacterial strain

FIRST DAY

3 DAYS

6 DAYS

9 DAYS

12 DAYS

%OF BOD REMOVAL AFTER 12 DAYS

1

Bacillus sp

45

41

35

29

26

42.22

2

Pseudomonas sp

45

38

34

29

24

46.66

3

Acineto bacter

45

37

32

30

27

40.0

4

Legionella

45

42

38

33

29

35.5

5

Staphylococcus

45

43

37

35

32

28.88

50 45

% BOD Removal by bacterial strain

40 35 30 25 20 15 10 5 0

Fig -3 3 BOD Removal by Baterial strain


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Table -4 pH variations by bacterial strain pH S.NO

Bacterial strain

FIRST

3

6

9

12

DAY

DAYS

DAYS

DAYS

DAYS

1

Bacillus sp

8.1

7.7

7.5

7.3

7.2

2

Pseudomonas sp

8.1

8.O

7.8

7.7

7.6

3

Acineto bacter

8.1

7.9

7.7

7.6

7.3

4

Legionella

8.1

7.8

7.6

7.5

7.4

5

Staphylococcus

8.1

8.O

7.9

7.7

7.5

pH

VARIATION

8 7.8 PH

7.6 7.4 7.2 7 6.8 7.7

8.O

7.9

7.8

8.O

8.1

8.1

8.1

8.1

8.1

Legionella

Staphylococcus

Bacillus sp Pseudomonas spAcineto sp bacter SAMPLE NO

FIG :4

pH

VARIATION BY BACERIAL STRAIN

In the present study, decolorization proceeded gradually even up to 12 days in effluent-adapted effluent bacterial treatment. Effluent adapted bacillus sp gave 35.68% reduction in color according acco to olukanni et al .but but present work gave 73% of decolorization of dye effluent only.


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The microbes utilized carbon, nitrogen and sulphate found in effluent medium for their nutrition. Decolorization % will be further increased and prolonged by supplementing the effluent medium with other cheaper effective carbon or energy source such as sucrose, starch and hydrolysed starch. Acineto bacter had high COD removal % (60.12) and pseudomonas sp had high BOD removal % (46.66)

4.CONCLUSION Bacteria is a cheaper and better environment friendlier alternative for colour removal in textile dye effluents.biological treatment has been effective in reducing dye house effluents and when used properly has a lower operating cost than other remediation decolorization process. Microbial consortium has become a very good source for the textile industry in getting rid of theireffluent problem by Biodegradation and Decolorization process. Since they are cost effective and efficient it is highly recommended for the industries in making use of

the

consortium for the proper disposal of textile effluents.

5. REFERENCES [1]M. Iqbal, A. Saeed Process Biochem, 2007, 42, 1160-1164. [2] Z. Aksu, A.I. Tatli, O. Tunc, Chem Eng J, 2008 , 1422, 23-39. [3)]M.A. Khalaf, Bioresource Technol,2008, 99, 6631-6634. [4]O. Anjaneya, M. Santhosh kumar, S. Nayak Anand, T.B. Karegoudai, det Biodeg, 2009, 63, 782-787. [5]I. Kiran, S. Iihan, N. Caner, C.F. Iscen, Z. Y ildiz, Desalin,2009, 249, 273-278. [6]X.J. Xiong, X.J. Meng, T.L. Zheng, J Hazard Mater , 2010,175, 241-246. [7] Kapdan, K.I., F. Kargi, G. McMullan and R. Marchant (2000).: Effect of environmental conditions on biological decolorization of textile dyestuff by C. versicolor. Enzyme and Microbial Technoloy, 26, 381-387.


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[8] Faryal,R., Hameed,A. 2005. Isolation and characterization of various fungal strains from textile effluent for their use in bioremediation. Pak.J.Bot.; 1003-1008. [9] Khadijah,O., Lee,K.K., Mohd Faiz F., Abdullah. 2009. Isolation, screening and development of local bacterial consortia with azo dyes decolourising capability. Malaysian Journal of Microbiology.;25-32.



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Influence of “SUGAR CANE JUICE” on the corrosion resistance of orthodontic wires in artificial saliva A.Christy Catherine Mary, V.Jeslina, A. Subhashini mary, P.Geethanjali, .Geethanjali, G.Bowriya, J.ClaraAngelin , S.Rajendran, J.Jeyasundari

Influence of “SUGAR CANE JUICE” on the corrosion resistance of orthodontic wires in artificial saliva A.Christy Catherine Mary[1], V.Jeslina[1] , A.. Subhashini mary [1], P.Geethanjali[1], G.Bowriya[1], J.ClaraAngelin[1] S.Rajendran[2], J.Jeyasundari[3], [1] [2] Department of Chemistry, St.Antony’s College of Arts and Sciences for women, Thamaraipadi, Dindigul, India. Email: [email protected] [3]PG and Research Department of Chemistry, SVN College, Madurai, India.

Abstract Corrosion resistance of 22 carat gold, thermoactive alloy, in artificial saliva (AS) in the absence and presence of sugar cane juice has been evaluated by electrochemical studies such as polarization study. For 22 carat gold, thermoactive alloy, polarization study lead to the conclusion that corrosion resistance of 22 carat gold decreases in the order AS + sugar cane juice > sugar cane juice > AS For thermoactive alloy polarization study lead to the conclusion that corrosion resistance r of thermoactive alloy decreases in the order AS > sugar cane juice >AS + sugar cane juice Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

454

Influence of “SUGAR CANE JUICE” on the corrosion resistance of orthodontic wires in artificial saliva A.Christy Catherine Mary, V.Jeslina, A. Subhashini mary, P.Geethanjali, G.Bowriya, J.ClaraAngelin , S.Rajendran, J.Jeyasundari

People implanted with orthodontic wire, made of 22 carat gold can take sugar cane juice orally without any hesitation. People implanted with orthodontic wire, made of thermoactive alloy should avoid taking sugar cane juice. Keywords: corrosion resistance, orthodontic wires, artificial saliva, sugar cane juice, extract of natural products, 22 carat gold, thermoactive alloy polarization study.

1. Introduction To regulate the growth of teeth, dentist make use of orthodontic wires made of different metals and alloys. For this purpose orthodontic wires made of several metals and alloys have been used. Vieira et al., have studied the tribocorrosion of Ti in artificial saliva (AS) in presence of citric acid and sodium nitrate [1]. Mareci et al., have analysed the corrosion resistance of NiCo based alloy in AS [2].The influence of eugernol of the corrosion resistance of Ti in AS has been studied [3]. Ziebowicz et al., have evaluated the corrosion resistance of commercial metallic or wires in simulated intra-oral environmental [4]. Chenglong Liu et al., have studied the corrosion resistance of CrNi, NiTi, CuNiTi wires in AS [4]. Corrosion behaviors of NiTi orthodontic brackets in AS has been investigated [5]. Rajendran et al., have studied the corrosion behavior metals in AS in presence of spirulina powder [6]. Corrosion behavior metals in AS in presence of D-glucose has been investigated [7]. corrosion behavior of SS316L in AS in presence of

electoral has been studied by Rajendran et al., [8].The corrosion behavior of

Aluminium-bronze dental alloy in AS has been studied by polarization test , polarization resistance measurement and weight loss method [9]. The present work is undertaken to evaluate corrosion resistance of orthodontic wires made of 22 carat gold and Ni-Ti alloy in AS in presence of rasam by polarization study and AC impedance spectra.

2. Experimental Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

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Orthodontic wires made of Gold 22 carat and thermoactive alloy are used in the present study. The metal specimens were used as working electrode. They were immersed in Fusayamma Meyer artificial saliva whose composition is[8];

The pH of the solution was 6.5

2.1Preparation of Sugar cane juice Cleaned sugar cane was crushed and the extract was used in present study.

2.2 Polarization study Polarization studies were carried out in a CHI-Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The working electrode was mild steel coated with zinc SS316L. a saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr), and Tafel Slopes (anodic = ba and cathodic = bc) were calculated.

3. Result and Discussion 3.1 Analysis of Polarization curves Corrosion resistance of 22 carat gold, thermoactive alloy in various test solution has been evaluated by polarization study. When corrosion resistance increases Linear Polarization Resistance (LPR) increases; Corrosion current(Icorr) decreases. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

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3.2.

22 Carat Gold

The polarization curves of 22 carat gold immersed in various test solutions are shown in figure 1. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes ((bc= cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2.

Table2. Corrosion parameters of metals immersed in artificial saliva (AS) in the presence and absence of sugar cane juice, obtained by polarization study Metal

22 carat gold

Thermo active alloy

System

AS Sugar cane juice AS+ Sugar cane juice AS Sugar cane juice AS+ Sugar cane juice

Ecorr mV vs SCE

bc mV/ decade

ba mV/ decade

LPR ohm cm2

-398

223

331

1179450

-101

159

167

5781739

-416

563

176

6819415

-481

252

206

1854996

-437

130

286

13362295

-452

181

187

7043728

Icorr A/cm2 4.915 x10-8 0.6115x10-8 1.525x10-8 2.658x10-8 0.28951x10-8 0.5684x10-8

When 22 carat gold immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 1179450 ohm cm2. The Corrosion current(Icorr) is 4.915x10-8 A/ cm2 . The Corrosion Potential (Ecorr) is -398mV vs SCE. When 22 carat gold immersed in Sugar cane juice, Linear Polarization Resistance (LPR) value increases from 1179450 to 5781739 ohm cm2. The Corrosion current (Icorr) decreases from Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

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4.915x10-8 to 0.6115x10-8

A/ cm2 . This indicates that 22 carat gold is more corrosion resistant

in rasam. Further the Corrosion Potential (Ecorr) value shifts from -398 to -416 mV vs SCE When 22 carat gold immersed in the system consisting of AS and Sugar cane juice, the LPR value further increases to 6819415 ohm cm2.the corrosion current decreases to 1.525 x10-8 A/ cm2. This indicates the 22 carat gold is more corrosion resistant in AS + Sugar cane juice system than in Sugar cane juice system or AS system. Thus the polarization study leads to the conclusion that when 22 carat gold is immersed in various test solution, the decreasing order of corrosion resistance of 22 carat gold is as follows: AS + Sugar cane juice > Sugar cane juice > AS This study reveals that people having orthodontic wires made of 22 carat gold need not hesitate to take rasam. Because in this medium the corrosion resistance of 22 carat gold increases.

Fig 1 Polarisation curve of 22 Carat gold immersed in solution (a) AS (b) sugar cane juice


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Fig 2 Polarisation curve of 22 Carat gold immersed in solution (a) sugar cane juice

Inter Collegiate Meet-Fig National Level Seminar ongold “New Perspective and Technology”, 2 Polarisation curve of 22 Carat immersed in solutionin (a)Science AS th (NPST-2016), 7 October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

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3.3 Thermoactive alloy The polarization curves of thermoactive alloy immersed in various test solutions are shown in figure 2. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes ((bc= cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2. When thermoactive alloy immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 1854996 ohm cm2. The Corrosion current (Icorr) is 2.658x10-8 A/ cm2 . The Corrosion Potential (Ecorr) is -481mV vs SCE. When thermoactive alloy immersed in sugar cane juice, Linear Polarization Resistance (LPR) value decreases from 1854996 to 1336229 ohm cm2. The Corrosion current (Icorr) increases from 2.658x10-8 x10-8 to 0.2895 x10-8A/ cm2. This indicates that corrosion resistant of thermoactive alloy decreases in sugar cane juice, when compare to that in saliva system. When thermoactive alloy immersed in AS and

sugar cane juice system, the LPR value further

decreases and the corrosion current value further increases.

This indicates the corrosion

resistance of thermoactive alloy further decreases in AS + sugar cane juice system. Thus the polarization study leads to the conclusion that when thermoactive alloy is immersed in various test solution, the decreasing order of corrosion resistance of thermoactive alloy is as follows: AS > thermoactive alloy >AS + thermoactive alloy


460


This study suggest that people having orthodontic wires made of thermoactive alloy should avoid taking thermoactive alloy. Because in this medium the corrosion resistance of thermoactive alloy decreases.

Fig 2 Polarisation curve of 22 Carat gold immersed in solution (a) sugar cane juice (b) S+AS (c) AS

4. Conclusion 

Corrosion resistance of 22 carat gold and Thermoactive alloy in artificial saliva (AS) in

the absence and presence of sugar cane juice has been evaluated by electrochemical studies such as polarization study. 

For 22 carat gold alloy polarization study and to the conclusion that corrosion resistance

of 22 carat gold decreases in the order AS + sugar cane juice > sugar cane juice > AS


461




For Thermoactive alloy polarization study lead to the conclusion that corrosion resistance

of thermoactive alloy decreases in the order AS > sugar cane juice >AS + sugar cane juice 

People implanted with orthodontic wire, made of 22 carat gold alloy can take sugar cane

juice orally without any hesitation. 

People implanted with orthodontic wire, made of Thermoactive alloy should avoid

taking sugar cane juice.

5. Acknowledgment The authors are thankful to their respective managements, for their constant help and encouragement.

6. References [1]A.C. Vieira, A.R.Ribeiro, L.A.Rocha and J.P.Celis, Influence of pH and corrosion inhibitorsonthe tribocorrosion of titanium in artificial saliva, WEAR, 261(2006) 994. [2] D.Mareci, G.H.Nemtoi, N.Aelenei and C.Bocanu, TheElectrochemical Behaviour of Various Non-preciousNi and Co based alloys in Artificial Saliva, EuropeanCells and Materials, 10 (2005) 1. [3] L.Kinani and A.Chtaini, Corrosion inhibition oftitanium in artificial saliva containing fluoride,Leonardo Journal of Sciences, 11 (2007) 33-40. [4] A.Ziebowicz, W.Walke, A.Barucha-Kepka and M.Kiel, Corrosion behaviour of metallic biomaterialsused as orthodontic wires, Journal of Achievements in Materials and Manufacturing Engineering, 27 (2008)151-154. [5] Chenglong Liu, K.Paul, Chu, Guoqiang Lin and DazhiYang, Effects of Ti/TiN Multilayer on corrosionresistance of nickel-titanium orthodontic brackets inartificial saliva, CorrosionScience, 49 (2007) 3783. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

462


[6] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari andM. Manivanna, “Corrosion behavior ofmetals inartificial saliva, in present of spirulina powder”,Journal of Dentistry and oralhygiene,1(2009) 1-8. [7] S. Rajendran, V. Uma, A. Krishnaveni, J. Jeyasundari,B. Shyamaladevi and M. Manivannan, “CorrosionBehaviour of metals in artificial saliva in presence ofD-Glucose”, The Arabian Journal for Science andEngineering, 34(2C) (2009) 147-158. [8] S. Rajendran, P. Chitradevi, S. Johnmary, A. Krishnaveni, S. Kanchana, Lydia Christy, R. Nagalakshmi, B. Narayanasamy, “Corrosion behaviour of SS 316 L in artificial saliva in presence of electoral, ZAŠTITA MATERIJALA 51 (2010) 149-158. [9] S. Rajendran, S. ShanmugaPriya, T. Rajalakshmi and A.J. Amal Raj, Corrosion, 61(2005)685-692. [10] V. Sribharathy, SusaiRajendran ,P. Rengan, R. Nagalakshmi Eur. Chem. Bull. 2(7) (2013), 471-476. [11]R.Epshiba , A.Peter Pascal Regis and S.Rajendran Int.J.NanoCorros.Sci and Engg. 1(1) (2014) - 1 - 11. [12] N. Kavitha , P. Manjula Int.J.NanoCorros.Sci and Engg.1(1) (2014) 31 - 38. [13]R.

Nagalakshmi

,

L.

Nagarajan

,

R.JosephRathish,

S.SanthanaPrabha,N.Vijaya,

J.Jeyasundari and S. Rajendran Int.J.NanoCorros.SciandEngg. 1(1) (2014) 39 - 49. [14]J. AngelinThangakani, S. Rajendran and J.Sathiabama, R.M.Joany, R.JosephRathis ,S.Santhana Prabha Int.J.NanoCorros.Sci and Engg.1(1) (2014) 50 - 62. [15] A.Christy Catherine Mary, S.Rajendran,R Joseph Rathish, A


Inhibition by oxyanions, Int J Nano Corr Sci and Engg 2(3) (2015) 46-59.

Received-15-09-2016 Accepted-20-09-2016 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 454 - 463 Editors: Dr S Rajendran, A Christy Catherine Mary

463

Influence of “SUGAR CANE JUICE” on the corrosion resistance of Ni-Ti Ti alloy in presence of artificial saliva A.Christy Catherine Mary , A.S.Arshiya Fathima, X. Susmitha, D.Keerthana, A.Infant Deepa S.Rajendran, J.Jeyasundari

Influence of “SUGAR CANE JUICE” on the corrosion resistance of Ni-Ti Ti alloy in presence of artificial saliva A.Christy Catherine Mary[1],A.S.Arshiya A.S.Arshiya Fathima[1], X. Susmitha[1], D.Keerthana[1],A.Infant Deepa[1], S.Rajendran[2], J.Jeyasundari[3], [1] [2] Department of Chemistry, St.Antony’s College of Arts and Sciences for women, Thamaraipadi, Dindigul, India. Email: [email protected] [3]PG and Research Department of Chemistry, SVN College, Madurai, Madurai, India.

Abstract Corrosion resistance of Ni-Ti Ni alloy in artificial saliva (AS) in the absence and presence of sugar cane juice has been evaluated by electrochemical studies such as polarization. For Ni-Ti alloy,, polarization study lead to the conclusion that corrosion resistance of Ni-Ti Ti alloy decreases in the order AS + sugar cane juice > sugar cane juice > AS People implanted with orthodontic wire, made of Ni-Ti alloy can take sugar cane juice orally without any hesitation.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 463 - 470 Editors: Dr S Rajendran, A Christy Catherine Mary

464

Influence of “SUGAR CANE JUICE” on the corrosion resistance of Ni-Ti alloy in presence of artificial saliva A.Christy Catherine Mary , A.S.Arshiya Fathima, X. Susmitha, D.Keerthana, A.Infant Deepa S.Rajendran, J.Jeyasundari

Keywords: corrosion resistance, orthodontic wires, artificial saliva, sugar cane juice, extract of natural products, Ni-Ti alloy polarization study.




2. Experimental Orthodontic wires made of Ni-Ti alloy are used in the present study. The metal specimens were used as working electrode. They were immersed in Fusayamma Meyer artificial saliva whose composition is[8];


465



2.1Preparation of Sugar cane juice Cleaned sugar cane was crushed and the extract was used in present study


3. Result and Discussion 3.1 Analysis of Polarization curves Corrosion resistance of Ni-Ti alloy in various test solution has been evaluated by polarization study. When corrosion resistance increases Linear Polarization Resistance (LPR) increases; Corrosion current(Icorr) decreases.

3.2.

Ni-Ti alloy

The polarization curves of Ni-Ti alloy immersed in various test solutions are shown in figure 1. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes ((bc= Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 463 - 470 Editors: Dr S Rajendran, A Christy Catherine Mary

466


cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2.


Ni-Ti alloy

System

AS Sugar cane juice AS+ Sugar cane juice

Ecorr mV vs SCE

bc mV/ decade

ba mV/ decade

LPR ohm cm2

-587

209

225

2273190

-647

167

217

2456278

-633

158

222

4233439

Icorr A/cm2 2.074 x10-8 1.671x10-8 0.9470x10-8

When Ni-Ti alloy immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 2273190 ohm cm2. The Corrosion current(Icorr) is 2.074 x10-8A/ cm2 . The Corrosion Potential (Ecorr) is -587mV vs SCE. When Ni-Ti alloy immersed in Sugar cane juice, Linear Polarization Resistance (LPR) value increases from 2273190 to 2456278 ohm cm2. The Corrosion current (Icorr) decreases from 2.074 x10-8 to 1.671x10-8 A/ cm2 . This indicates that Ni-Ti alloy is more corrosion resistant in Sugar cane juice. Further the Corrosion Potential (Ecorr) value shifts from -587 to -633 mV vs SCE When Ni-Ti alloy immersed in the system consisting of AS and Sugar cane juice, the LPR value further increases to 4233439 ohm cm2.the corrosion current decreases to 0.9470x10-8 A/ cm2. This indicates the Ni-Ti alloy is more corrosion resistant in AS + Sugar cane juice system than in Sugar cane juice system or AS system. Thus the polarization study leads to the conclusion that Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 463 - 470 Editors: Dr S Rajendran, A Christy Catherine Mary

467


when Ni-Ti alloy is immersed in various test solution, the decreasing order of corrosion resistance of Ni-Ti alloy is as follows: AS + Sugar cane juice > Sugar cane juice > AS This study reveals that people having orthodontic wires made of Ni-Ti alloy need not hesitate to take sugar cane juice. Because in this medium the corrosion resistance of Ni-Ti alloy increases.

Fig 1 Polarisation curve of 22 Carat gold immersed in solution (a) sugar cane juice (b)S+ AS (c) AS

4. Conclusion 

Corrosion resistance of Ni-Ti alloy in artificial saliva (AS) in the absence and presence of

sugar cane juice has been evaluated by electrochemical studies such as polarization study. 

For Ni-Ti alloy polarization study and to the conclusion that corrosion resistance of Ni-Ti

alloy decreases in the order Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 463 - 470 Editors: Dr S Rajendran, A Christy Catherine Mary

468


AS + sugar cane juice > sugar cane juice > AS 

People implanted with orthodontic wire, made of Ni-Ti alloy can take sugar cane juice

orally without any hesitation.


6. References [1]A.C. Vieira, A.R.Ribeiro, L.A.Rocha and J.P.Celis, Influence of pH and corrosion inhibitorsonthe tribocorrosion of titanium in artificial saliva, WEAR, 261(2006) 994. [2] D.Mareci, G.H.Nemtoi, N.Aelenei and C.Bocanu, TheElectrochemical Behaviour of Various Non-preciousNi and Co based alloys in Artificial Saliva, EuropeanCells and Materials, 10 (2005) 1. [3] L.Kinani and A.Chtaini, Corrosion inhibition oftitanium in artificial saliva containing fluoride,Leonardo Journal of Sciences, 11 (2007) 33-40. [4] A.Ziebowicz, W.Walke, A.Barucha-Kepka and M.Kiel, Corrosion behaviour of metallic biomaterialsused as orthodontic wires, Journal of Achievements in Materials and Manufacturing Engineering, 27 (2008)151-154. [5] Chenglong Liu, K.Paul, Chu, Guoqiang Lin and DazhiYang, Effects of Ti/TiN Multilayer on corrosionresistance of nickel-titanium orthodontic brackets inartificial saliva, CorrosionScience, 49 (2007) 3783. [6] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari andM. Manivanna, “Corrosion behavior ofmetals inartificial saliva, in present of spirulina powder”,Journal of Dentistry and oralhygiene,1(2009) 1-8. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 463 - 470 Editors: Dr S Rajendran, A Christy Catherine Mary

469


[7] S. Rajendran, V. Uma, A. Krishnaveni, J. Jeyasundari,B. Shyamaladevi and M. Manivannan, “CorrosionBehaviour of metals in artificial saliva in presence ofD-Glucose”, The Arabian Journal for Science andEngineering, 34(2C) (2009) 147-158. [8] S. Rajendran, P. Chitradevi, S. Johnmary, A. Krishnaveni, S. Kanchana, Lydia Christy, R. Nagalakshmi, B. Narayanasamy, “Corrosion behaviour of SS 316 L in artificial saliva in presence of electoral, ZAŠTITA MATERIJALA 51 (2010) 149-158. [9] S. Rajendran, S. ShanmugaPriya, T. Rajalakshmi and A.J. Amal Raj, Corrosion, 61(2005)685-692. [10] V. Sribharathy, SusaiRajendran ,P. Rengan, R. Nagalakshmi Eur. Chem. Bull. 2(7) (2013), 471-476. [11]R.Epshiba , A.Peter Pascal Regis and S.Rajendran Int.J.NanoCorros.Sci and Engg. 1(1) (2014) - 1 - 11. [12] N. Kavitha , P. Manjula Int.J.NanoCorros.Sci and Engg.1(1) (2014) 31 - 38. [13]R.

Nagalakshmi

,

L.

Nagarajan

,

R.JosephRathish,







470

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari,

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary[1], S.Suganya[1], G.Deiva[1], S.Bhuvaneshwari[1], M.Vijaya Sri[1], G.Geetha[1] , S.Rajendran[2], J.Jeyasundari[3], [1] [2] Department of Chemistry, St.Antony’s College of Arts and Sciences for women, Thamaraipadi, Dindigul, India. Email: [email protected] [3]PG and Research Department of Chemistry, SVN College, Madurai, India.

Abstract Corrosion resistance of SS18/8 alloy in artificial saliva (AS) in the absence and presence of sugar cane juice has been evaluated by electrochemical studies such as polarization. For SS18/8 alloy,, polarization study lead to the conclusion conclusion that corrosion resistance of SS18/8 alloy decreases in the order Sugar cane juice >AS > AS + Sugar cane juice People implanted with orthodontic wire, made of SS18/8 alloy should avoid to take sugar cane juice orally.

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 471 - 477 Editors: Dr S Rajendran, A Christy Catherine Mary

471

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari, Keywords: corrosion resistance, orthodontic wires, artificial saliva, sugar cane juice, extract of natural products, SS18/8 alloy polarization study.




2. Experimental Orthodontic wires made of SS18/8 alloy are used in the present study. The metal specimens were used as working electrode. They were immersed in Fusayamma Meyer artificial saliva whose composition is[8];


472



2.1Preparation of Sugar cane juice Cleaned sugar cane was crushed and the extract was used in present study


3. Result and Discussion 3.1 Analysis of Polarization curves Corrosion resistance of SS18/8 alloy in various test solution has been evaluated by polarization study. When corrosion resistance increases Linear Polarization Resistance (LPR) increases; Corrosion current(Icorr) decreases.

3.2.

SS18/8 alloy

The polarization curves of SS18/8 alloy immersed in various test solutions are shown in figure 1. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes ((bc= Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 471 - 477 Editors: Dr S Rajendran, A Christy Catherine Mary

473

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari, cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2.


SS18/8 alloy

System

AS Sugar cane juice AS+ Sugar cane juice

Ecorr mV vs SCE

bc mV/ decade

ba mV/ decade

LPR ohm cm2

-414

265

205

11768307

-479

156

191

2469717

-472

174

445

11010133

Icorr A/cm2 0.4271 x10-8 1.514x10-8 0.4947x10-8

When SS18/8 alloy immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 11768307 ohm cm2. The Corrosion current(Icorr) is 0.4271 x10-8A/ cm2 . The Corrosion Potential (Ecorr) is -414mV vs SCE. When SS18/8 alloy immersed in Sugar cane juice, Linear Polarization Resistance (LPR) value increases from 11768307 to 2469717ohm cm2. The Corrosion current (Icorr) decreases from 0.4271 x10-8 to 1.514x10-8 A/ cm2 . This indicates that SS18/8 alloy is more corrosion resistant in Sugar cane juice. Further the Corrosion Potential (Ecorr) value shifts from -414 to -479 mV vs SCE

When SS18/8 alloy immersed in the system consisting of AS and Sugar cane juice, the

LPR value further decreases to 11010133 ohm cm2.the corrosion current increases to 0.4947x10-8 A/ cm2. This indicates the SS18/8 alloy is less corrosion resistant in AS + Sugar cane juice system than in Sugar cane juice system or AS system. Thus the polarization study leads to the Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 471 - 477 Editors: Dr S Rajendran, A Christy Catherine Mary

474

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari, conclusion that when SS18/8 alloy is immersed in various test solution, the decreasing order of corrosion resistance of SS18/8 alloy is as follows: Sugar cane juice >AS > AS + Sugar cane juice This study reveals that people having orthodontic wires made of SS18/8 alloy should avoid to take sugar cane juice. Because in this medium the corrosion resistance of SS18/8 alloy decreases.

Fig 1 Polarisation curve of SS18/8 immersed in solution (a) AS (b) sugar cane juice (c) S+ AS

4. Conclusion 

Corrosion resistance of SS18/8 alloy in artificial saliva (AS) in the absence and presence

of sugar cane juice has been evaluated by electrochemical studies such as polarization study. 

For SS18/8 alloy polarization study and to the conclusion that corrosion resistance of

SS18/8 alloy decreases in the order Sugar cane juice >AS > AS + Sugar cane juice Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 471 - 477 Editors: Dr S Rajendran, A Christy Catherine Mary

475




People implanted with orthodontic wire, made of SS18/8 alloy should avoid to take sugar

cane juice orally.


6. References [1]A.C. Vieira, A.R.Ribeiro, L.A.Rocha and J.P.Celis, Influence of pH and corrosion inhibitorsonthe tribocorrosion of titanium in artificial saliva, WEAR, 261(2006) 994. [2] D.Mareci, G.H.Nemtoi, N.Aelenei and C.Bocanu, TheElectrochemical Behaviour of Various Non-preciousNi and Co based alloys in Artificial Saliva, EuropeanCells and Materials, 10 (2005) 1. [3] L.Kinani and A.Chtaini, Corrosion inhibition oftitanium in artificial saliva containing fluoride,Leonardo Journal of Sciences, 11 (2007) 33-40. [4] A.Ziebowicz, W.Walke, A.Barucha-Kepka and M.Kiel, Corrosion behaviour of metallic biomaterialsused as orthodontic wires, Journal of Achievements in Materials and Manufacturing Engineering, 27 (2008)151-154. [5] Chenglong Liu, K.Paul, Chu, Guoqiang Lin and DazhiYang, Effects of Ti/TiN Multilayer on corrosionresistance of nickel-titanium orthodontic brackets inartificial saliva, CorrosionScience, 49 (2007) 3783. [6] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari andM. Manivanna, “Corrosion behavior ofmetals inartificial saliva, in present of spirulina powder”,Journal of Dentistry and oralhygiene,1(2009) 1-8. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 471 - 477 Editors: Dr S Rajendran, A Christy Catherine Mary

476

Can people implanted with SS18/8 alloy orthodontic wire drink “SUGAR CANE JUICE” orally? A.Christy Catherine Mary, S.Suganya, G.Deiva, S.Bhuvaneshwari, M.Vijaya Sri, G.Geetha S.Rajendran, J.Jeyasundari, [7] S. Rajendran, V. Uma, A. Krishnaveni, J. Jeyasundari,B. Shyamaladevi and M. Manivannan, “CorrosionBehaviour of metals in artificial saliva in presence ofD-Glucose”, The Arabian Journal for Science andEngineering, 34(2C) (2009) 147-158. [8] S. Rajendran, P. Chitradevi, S. Johnmary, A. Krishnaveni, S. Kanchana, Lydia Christy, R. Nagalakshmi, B. Narayanasamy, “Corrosion behaviour of SS 316 L in artificial saliva in presence of electoral, ZAŠTITA MATERIJALA 51 (2010) 149-158. [9] S. Rajendran, S. ShanmugaPriya, T. Rajalakshmi and A.J. Amal Raj, Corrosion, 61(2005)685-692. [10] V. Sribharathy, SusaiRajendran ,P. Rengan, R. Nagalakshmi Eur. Chem. Bull. 2(7) (2013), 471-476. [11]R.Epshiba , A.Peter Pascal Regis and S.Rajendran Int.J.NanoCorros.Sci and Engg. 1(1) (2014) - 1 - 11. [12] N. Kavitha , P. Manjula Int.J.NanoCorros.Sci and Engg.1(1) (2014) 31 - 38. [13]R.

Nagalakshmi

,

L.

Nagarajan

,

R.JosephRathish,







477

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin A.Lidvin Daisy, M.Afritha M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary[1],A.Lidvin Daisy[1] , M.Afritha[1], K.Divya[1] ,N.Sugantha[1] S.Rajendran[2], J.Jeyasundari[3], [1] [2] Department of Chemistry, St.Antony’s College of Arts and Sciences for women, Thamaraipadi, Dindigul, India. Email: [email protected] [3]PG and Research Department of Chemistry, SVN College, Madurai, India.

Abstract Corrosion resistance of SS316L SS alloy in artificial saliva (AS) in the absence and presence of Neem Stick Extract has been evaluated by electrochemical studies such as polarization. For SS316L alloy,, polarization study lead to the conclusion that corrosion resistance of SS316L alloy decreases in the order Neem Stick Extract > AS + Neem Stick Extract >AS People implanted with orthodontic wire, made of SS316L alloy need not hesitate to clean their teeth with neem stick. Keywords: corrosion resistance, orthodontic wires, artificial saliva, extract of neem stick , SS316L alloy polarization study.. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST (NPSTth 2016), 7 October, 2016- St Antony’s College of Arts and Sciences for Women, TThamaraipadi, amaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 478-484 478 Editors: Dr S Rajendran, A Christy Catherine Mary, Mary P.Nithya Devi

478

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari

1. Introduction To regulate the growth of teeth, dentist make use of orthodontic wires made of different metals and alloys. For this purpose orthodontic wires made of several metals and alloys have been used. Vieira et al., have studied the tribocorrosion of Ti in artificial saliva (AS) in presence of citric acid and sodium nitrate [1]. Mareci et al., have analysed the corrosion resistance of Ni-Co based alloy in AS [2].The influence of eugernol of the corrosion resistance of Ti in AS has been studied [3]. Ziebowicz et al., have evaluated the corrosion resistance of commercial metallic or wires in simulated intra-oral environmental [4]. Chenglong Liu et al., have studied the corrosion resistance of CrNi, NiTi, CuNiTi wires in AS [4]. Corrosion behaviors of NiTi orthodontic brackets in AS has been investigated [5]. Rajendran et al., have studied the corrosion behavior metals in AS in presence of spirulina powder [6]. Corrosion behavior metals in AS in presence of D-glucose has been investigated [7]. corrosion behavior of SS316L in AS in presence of electoral has been studied by Rajendran et al., [8].The corrosion behavior of Aluminium-bronze dental alloy in AS has been studied by polarization test , polarization resistance measurement and weight loss method [9]. The present work is undertaken to evaluate corrosion resistance of orthodontic wires made of 22 carat gold and Ni-Ti alloy in AS in presence of rasam by polarization study and AC impedance spectra.

2. Experimental Orthodontic wires made of SS316L alloy are used in the present study. The metal specimens were used as working electrode. They were immersed in Fusayamma Meyer artificial saliva whose composition is[8];

Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 478-484 Editors: Dr S Rajendran, A Christy Catherine Mary, P.Nithya Devi

479

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari


2.1Preparation of Neem Stick Extract Neem sticks were cut down from neem tree. They were dried in the shade. 50gms of the sticks was boiled with distilled water and the extract was made upto 100ml. 2.2 Polarization study Polarization studies were carried out in a CHI-Electrochemical workstation with impedance, Model 660A. A three-electrode cell assembly was used. The working electrode was mild steel coated with zinc SS316L. a saturated calomel electrode (SCE) was the reference electrode and platinum was the counter electrode. From the polarization study, corrosion parameters such as corrosion potential (Ecorr), corrosion current (Icorr), and Tafel Slopes (anodic = ba and cathodic = bc) were calculated.

3. Result and Discussion 3.1 Analysis of Polarization curves Corrosion resistance of SS316L alloy in various test solution has been evaluated by polarization study. When corrosion resistance increases Linear Polarization Resistance (LPR) increases; Corrosion current(Icorr) decreases.

3.2.

SS316L alloy


480

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari The polarization curves of SS316L alloy immersed in various test solutions are shown in figure 1. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes ((bc= cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2. Table2. Corrosion parameters of metals immersed in artificial saliva (AS) in the presence and absence of sugar cane juice, obtained by polarization study Metal

SS316L alloy

System

AS Neem Stick Extarct AS+ Neem Stick extarct

Ecorr mV vs SCE

bc mV/ decade

ba mV/ decade

LPR ohm cm2

-567

165

275

2117936

-597

170

222

4499340

-702

162

243

4160711

Icorr A/cm2 2.115 x10-8 0.9309x10-8 1.014x10-8

When SS316L alloy immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 2117936 ohm cm2. The Corrosion current(Icorr) is 2.115 x10-8A/ cm2 . The Corrosion Potential (Ecorr) is -567mV vs SCE. When SS316L alloy immersed in Neem Stick extract, Linear Polarization Resistance (LPR) value increases from 2117936 to 4499340 ohm cm2. The Corrosion current (Icorr) decreases from 2.115 x10-8 to 0.9309x10-8 A/ cm2 . This indicates that SS316L alloy is more corrosion resistant in Neem Stick extract. Further the Corrosion Potential (Ecorr) value shifts from -567 to -702 mV vs SCE When SS316L alloy immersed in the system consisting of AS and Neem Stick extract, the LPR value further decreases to 4160722 ohm cm2.the corrosion current increases to 1.014x10-8 A/ cm2. This indicates the SS316L alloy is less corrosion resistant in AS + Neem Stick extract system than in Neem Stick extract system or AS system. Thus the polarization study leads to the


481

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari conclusion that when SS316L alloy is immersed in various test solution, the decreasing order of corrosion resistance of SS316L alloy is as follows: Neem Stick Extract > AS + Neem Stick Extract >AS This study reveals that people having orthodontic wires made of SS316L alloy need not hesitate to clean their teeth with neem stick.

Fig 1 Polarisation curve of SS316L immersed in solution (a) Neem stick extract(b) Neem (c) AS

4. Conclusion 

Corrosion resistance of SS316 Lalloy in artificial saliva (AS) in the absence and presence

of sugar cane juice has been evaluated by electrochemical studies such as polarization study. 

For SS316 Lalloy polarization study and to the conclusion that corrosion resistance of

SS316 Lalloy decreases in the order Neem Stick Extract > AS + Neem Stick Extract >AS


482

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari People implanted with orthodontic wire, made of SS316 L alloy need not hesitate to clean their teeth with neem stick.


6. References [1]A.C. Vieira, A.R.Ribeiro, L.A.Rocha and J.P.Celis, Influence of pH and corrosion inhibitorsonthe tribocorrosion of titanium in artificial saliva, WEAR, 261(2006) 994. [2] D.Mareci, G.H.Nemtoi, N.Aelenei and C.Bocanu, TheElectrochemical Behaviour of Various Non-preciousNi and Co based alloys in Artificial Saliva, EuropeanCells and Materials, 10 (2005) 1. [3] L.Kinani and A.Chtaini, Corrosion inhibition oftitanium in artificial saliva containing fluoride,Leonardo Journal of Sciences, 11 (2007) 33-40. [4] A.Ziebowicz, W.Walke, A.Barucha-Kepka and M.Kiel, Corrosion behaviour of metallic biomaterialsused as orthodontic wires, Journal of Achievements in Materials and Manufacturing Engineering, 27 (2008)151-154. [5] Chenglong Liu, K.Paul, Chu, Guoqiang Lin and DazhiYang, Effects of Ti/TiN Multilayer on corrosionresistance of nickel-titanium orthodontic brackets inartificial saliva, CorrosionScience, 49 (2007) 3783. [6] S. Rajendran, J. Paulraj, P. Rengan, J. Jeyasundari andM. Manivanna, “Corrosion behavior ofmetals inartificial saliva, in present of spirulina powder”,Journal of Dentistry and oralhygiene,1(2009) 1-8. [7] S. Rajendran, V. Uma, A. Krishnaveni, J. Jeyasundari,B. Shyamaladevi and M. Manivannan, “CorrosionBehaviour of metals in artificial saliva in presence ofD-Glucose”, The Arabian Journal for Science andEngineering, 34(2C) (2009) 147-158. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 478-484 Editors: Dr S Rajendran, A Christy Catherine Mary, P.Nithya Devi

483

Can people implanted with SS18/8 alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary ,A.Lidvin Daisy, M.Afritha, K.Divya ,N.Sugantha S.Rajendran, J.Jeyasundari [8] S. Rajendran, P. Chitradevi, S. Johnmary, A. Krishnaveni, S. Kanchana, Lydia Christy, R. Nagalakshmi, B. Narayanasamy, “Corrosion behaviour of SS 316 L in artificial saliva in presence of electoral, ZAŠTITA MATERIJALA 51 (2010) 149-158. [9] S. Rajendran, S. ShanmugaPriya, T. Rajalakshmi and A.J. Amal Raj, Corrosion, 61(2005)685-692. [10] V. Sribharathy, SusaiRajendran ,P. Rengan, R. Nagalakshmi Eur. Chem. Bull. 2(7) (2013), 471-476. [11]R.Epshiba , A.Peter Pascal Regis and S.Rajendran Int.J.NanoCorros.Sci and Engg. 1(1) (2014) - 1 - 11. [12] N. Kavitha , P. Manjula Int.J.NanoCorros.Sci and Engg.1(1) (2014) 31 - 38. [13]R. Nagalakshmi , L. Nagarajan , R.JosephRathish, S.SanthanaPrabha,N.Vijaya, J.Jeyasundari and S. Rajendran Int.J.NanoCorros.SciandEngg. 1(1) (2014) 39 - 49. [14]J. AngelinThangakani, S. Rajendran and J.Sathiabama, R.M.Joany, R.JosephRathis ,S.Santhana Prabha Int.J.NanoCorros.Sci and Engg.1(1) (2014) 50 - 62. [15] A.Christy Catherine Mary, S.Rajendran,R Joseph Rathish, A





484

Inhibition of acidic corrosion of mild steel by some organic compounds. Geetha M.B, Susai Rajendran

Inhibition of acidic corrosion of mild steel by some organic compounds. Geetha M.B1*, Susai Rajendran 2 1Department of Chemistry, St. Michael College of Engineering & Technology, Kalayarkoil Sivagangai. 630 551,Tamil Nadu, India. 2 Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul 624 005,Tamil Nadu, India. Email: [email protected] *Corres.author: [email protected] Phone- 09842122752 Abstract This paper analyzes inhibitive effect in the corrosion of mild steel using Urea, Zn2+ and LPhenylalanine as inhibitors in sulphuric acid solution at pH-4. The inhibitor efficiency was calculated using the weight loss method. The system was found to have 93% Inhibition efficiency. Polarization study reveals that urea -Zn -L- phenylalanine system functions as a mixed - type 2+

inhibitor. The formation of protective film has been confirmed by FTIR.

Keywords: Corrosion; Mild steel; Urea; L-Phenylalanine; Weight loss method.

492 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


1. Introduction Mild steel finds a variety of applications industrially, for mechanical and structural purposes, like bridge work, building, boiler plates, steam engine parts and automobiles. It finds various uses in most of the chemical industries due to its low cost and easy availability for fabrication of various reaction vessels, tanks, pipes etc. Since it suffers from severe corrosion in aggressive environment, it has to be protected. Acids like HCl and H2SO4 have been used for drilling operations, pickling baths and in decaling processes. Corrosion of mild steel and its alloys in different acid media have been extensively studied [1-4]. It has been reported that addition of certain organic compounds bearing hetero atoms, retards the corrosion of mild steel in acidic environments, [5-6.].Recently considerable interest has been generated in the use of nitrogen, oxygen and sulphur containing organic compounds as corrosion inhibitor for mild steel in different acids [7-8]. Among various organic compounds, urea and its derivatives shows significant corrosion inhibition of metals and alloys in corrosive media. As urea molecule contains one oxygen and two nitrogen atoms, hence urea and its derivatives can act as very good corrosion inhibitors [9-11]. The aim of the present study was to investigate the corrosion inhibition of various concentration of urea in the absence and presence of Zn2+ in sulphuric acid solution at pH - 4 .The inhibition efficiency was enhanced by adding various concentrations of L-phenylalanine. The corrosion inhibition efficiency was calculated using weight loss. The protective film formed on the metal surface characterized using FTIR.



2. Methods 2.1 Specimen Preparation Mild steel specimen (0.026% S, 0.06% P, 0.4% Mn and 0.1% C and rest iron), with dimensions of 1.0 X 4.0 X 0.2 cm were polished to get a mirror finish. The specimen was degreased with trichloroethylene and used in weight-loss method and surface examination studies. 2.2 The Weight – Loss Method: Mild steel triplicate specimens were immersed for 24 Hrs in 100 ml of the sulphuric acid solution at pH-4, with or without varying inhibitor concentrations. It was then cleaned with Clark’s solution [12]. The weight of the specimens before and after immersion were determined using a digital balance and the inhibition efficiency was calculated using the equation IE  100[1  (W2 /W1 )] %

Where

--- (1)

W1 is the weight loss in the absence of an inhibitor and W2 is the weight loss in

presence of an inhibitor. 2.3 Potentiodynamic Polarization Study Polarization study was carried out with an Electrochemical Impedance Analyzer, model CHI 660A, using a three electrode cell assembly. The working electrode was a rectangular specimen of mild steel. A constant area of 1 cm2 of the electrode was exposed.

A saturated calomel

electrode (SCE) was used as reference electrode. A rectangular platinum foil was used as the counter electrode. Polarization curves were recorded by doing iR compensation. During the 494 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


polarization study, the scan rate (V/s) was found to be 0.005, Hold time at Ef (s) was found to be zero and the quiet time (s) was 2.

Figure 1 . Circuit diagram of three-electrode cell assembly 2.4 FTIR spectra: The FTIR spectra were recorded using a Perkin Elmer1600 spectrophotometer. The film formed on the metal surface was carefully removed and thoroughly mixed with KBr, so as to make it uniform throughout.

3. Result and Discussion 3.1 Weight Loss Results Analysis Corrosion inhibition of binary inhibitor system, Urea-Zn2+ was shown in table 1. In order to achieve higher IE at lower concentration levels of binary inhibitor system, various



concentrations of another inhibitor, L-Phenylalanine is added to 150 ppm of Urea and 25 ppm of Zn2+ and the experimental results are given in table 2.

Table 1 Corrosion rates (CR) and inhibition various inhibitors in controlling the corrosion of MS immersed in H2SO4 solution at pH-4 obtained by weight loss method.

Zn 2+ 0 ppm

Urea ppm

IE %

CR

mm/y

Zn 2+- 25ppm IE %

CR

mm/y

0

---

0.1947

10

0.1762

50

21

0.1530

43

0.1113

100

31

0.1344

57

0.0834

150

33

0.1297

65

0.0672

200

36

0.1252

67

0.06493

250

38

0.1205

69

0.06029

Urea ppm

Zn2+ ppm

L-Phenylalanine

Corrosion

ppm

Rate

I.E %

mm/y



0

0

0

0.1947

---

0

25

0

0.1762

10

150

25

50

0.02087

89

150

25

100

0.01855

91

150

25

150

0.01855

91

150

25

200

0.01623

92

150

25

250

0.01391

93

Urea inhibits the corrosion of MS. As the concentration of Urea increases, the IE increases. When 25 ppm of Zn2+ is added to Urea, the IE increases with increase in the Urea concentration. 25 ppm of Zn2+ has 10 percent IE and 250 ppm of Urea have 38 % IE. The combination of 250 ppm of Urea and 25 ppm of Zn2+ shows 69 %.

It is found that when L-Phenylalanine is added, the IE of Urea-Zn2+ increases. The combination of 150 ppm Urea, 25 ppm Zn2+ and 250 ppm L-Phenylalanine shows 93 %. Therefore, this ternary combination shows more IE than the individual inhibitors. A Synergistic effect exists between Urea-Zn2+ and L-Phenylalanine. Due to synergism, IE increases and corrosion rate decreases. 3.2 Analysis of polarization curves Table 3 presented the corrosion parameters of mild steel immersed in sulphuric acid solution at pH-4 for 24 hours namely the corrosion current ( corr), cathodic Tafel slope (bc) and anodic Tafel slope (ba). Fig.2 represents the polarization curves of mild steel immersed in sulphuric acid solution at pH- 4 for 24 hours, in the absence and presence of inhibitors. 497 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


Table 3. Polarization Corrosion Parameters of mild steel immersed in sulphuric acid solution at pH-4 for 24 hours Urea Zn2+

L-

Ecorr

ppm

Phenylalanine

ppm

bc

ba

LPR

Icorr

mV vs. mV/decade

mV/dec

ohm cm2

A/cm2

ppm

SCE

ade

0

0

0

-598

205

167

16724.9

2.394x10-6

150

25

250

- 639

192

159

53202.3

7.107 x10-7

It can be found that in the presence of inhibitors, both the cathodic and anodic reactions are inhibited. Cathodic reactions are more controlled, since the corrosion potential, Ecorr shifts catholically.

An addition of 150 ppm of urea and 25 ppm of Zn2+ and 250 ppm of L-

phenylalanine decreased the metal dissolution while retarding hydrogen evolution. The shifts were found to be marginal. A compound is classified as anodic or cathodic based on the value of ECorr when it is greater than 85 mV [13]. The largest displacement exhibited by the proposed inhibitor system was 41 mV. So this system considered as mixed inhibitor. Corrosion current, Icorr decreased considerably with the addition of inhibitors. These observations indicate the formation of protective film on the metal surface [14-17].



Fig.2 Polarization curves of mild steel immersed in various test solutions a) Sulphuric acid solution at pH-4 b) Sulphuric acid solution at pH-4 containing 150 ppm of Urea + 25 ppm of Zn2+ + 250 ppm of L-phenylalanine. 3.3 FTIR Spectra Analysis The formation of protective film on the surface were studied by FTIR and important peaks discussed [18]. Fig. 3 depicts FTIR spectra of pure urea, pure L-phenylalanine and film formation on the metal surface after the immersion in sulphuric acid solution at pH-4 containing urea, Zn2+ and L-phenylalanine. The FTIR spectrum (KBr) of pure Urea is depicted in Fig.3 (a). The C=O stretching frequency appeared at 1594.55 cm-1 while the N – H stretching frequency appeared at 3415.60 cm-1. The N 499 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


– H bending frequency appeared at 1391.12 cm-1 and C – N stretching frequency appeared at 1474.47 cm-1.. Fig. 2(b) depicts the FTIR spectrum (KBr) of pure L-phenylalanine.

Fig. 3 (a) - FTIR spectrum (KBr) of pure Urea



Fig.3 (b) - FTIR spectrum (KBr) of pure L-Phenylalanine

Fig 3 (c) - FTIR spectrum of the film formed on the metal surface after immersion in sulphuric solution at pH-4 with urea, Zn2+ and L-Phenylalanine . In L-phenylalanine, The C=O stretching frequency of carboxyl appeared at 1732.92cm-1, C-N stretching frequency appeared at 1125.03 cm-1, The N-H stretching frequency of amine appeared at 3410.43cm-1. Fig 3 (c) depicts the FTIR spectrum of the film formed on the metal surface after immersion in sulphuric solution at pH-4 containing urea (150 ppm) and Zn2+ (25 ppm) and 250 ppm of L-phenylalanine. Various shifts in frequencies were observed which showed Urea and L-phenylalanine bonded with Fe2+, resulting in the formation of Fe2+ -Urea- L-Phenylalanine complex on the metal surface. 4.Conclusions This paper has analyzed inhibitive effect in the corrosion of mild steel using sulphuric acid solution at pH-4, with a new combination of Urea, Zn2+ and L-Phenylalanine as inhibitors. The 501 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


ternary system consisting of 150ppm urea, 25ppm Zn2+ and 250ppm L-phenylalanine has a good inhibition efficiency of 93%. Polarization results show that the inhibitor system acts as a mixed type inhibitor. FTIR results confirmed the formation of a protective film formed and corrosion inhibition occur due to the adsorption of inhibitors on the surface of mild steel. These inhibitors form a complex acting as a inhibitive layer on the metal surface and controlling corrosion. 5. References 1. Quarishi M.A., Rawat J. and Ajmal M., Corros., its control, Proc. Int Conf. Corros., 2, 634, (1997) 2. Laskawiec J., Sozanska B., Trzcionka J., Koroz Sukurczynska, 38, 249 (1995) 3. Shibad P.R. and Adhe K.N., Electrochem J. Sec.(India), 30, 103 (1981) 4. Shibad P.R., Electrochem J. Soc. (India), 27, 55,(1987)5. Yadav P.N. and Wadhwani R., Trans. SAEST, 25,134, (1993) 5. Yadav P.N. and Wadhwani R., Trans. SAEST, 25,134, (1993) 6. Edwards B.C., Corros. Sci., 9, 395 (1969) 7. Abdennabi A.M.S. and Addulhadi A.I. Abu-orabis,Anti Corrros. Meth. and Mat., 45, 103 (1998) 8. Suetaka W., Bull. Chem. Soc., 37, 112 (1964) [9] Joseph M. Sandri, John M. Calentine, Paadena and Seymour M. Liner, United States Patent 19: (1980). [10] Da-Quan Zhang, Li-Xin Gao and Guo-Ding Zhou, Surface and Coatings Technology 204: 1646-1650 (2010). 502 Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 492-503 Editors: Dr S Rajendran,


[11] D. Prakash singh, R. Kumar, G. Udayabhanu kumari and Ranju, Bulleting of Electrochemistry 22: 257-262 (2006). [12] G. Wranglen, Introduction to Corrosion and Protection of Metals, Chapman and Hall, London, 236 (1985). [13] XJ. Raj & Rajendran, N 1, International Journal of Electrochemical Science, Vol.6, no., pp. 348-366. (2011). [14] S. Shanthi, J. Arockia Selvi, S. Agnesia Kanimozhi, S. Rajendran, A. John Amalraj, B. Narayanasamy and N. Vijaya, Journal of Electrochemical Society of India 56 ½ : 48-51 (2007). [15] X. Joseph Raj and N. Rajendran, , International Journal of Electrochemical Science 6: 348366 (2011). [16] S. Agnesia Kanimozhi and S. Rajendran, , The Open Corrosion Journal 2: 166-174 (2009). [17] M. Manivannan and S. Rajendran, 1 (2): 241-249 (2011). [18] M. Srimathi , R. Rajalakshmi, S. Subhashini , Arabian Journal of Chemistry. 7: 647–656. (2010) 647–656.



Can people implanted with Thermoactive alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary,P.Nandhini, P.Nandhini, U.Veeranagammal, S.Selvarathinam, Kohila, Kohila S.Rajendran, J.Jeyasundari,

Can people implanted with Thermoactive alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary[1], P.Nandhini[1], U.Veeranagammal[1], S.Selvarathinam[1], Kohila[1] S.Rajendran[2], J.Jeyasundari[3] [1] [2] Department of Chemistry, St.Antony’s College of Arts and Sciences for women, Thamaraipadi, Dindigul, India. Email: [email protected] [3]PG and Research Department of Chemistry, SVN College, Madurai, India.

Abstract Corrosion resistance of Thermoactive alloy in artificial saliva (AS) in the absence and presence of Neem Stick Extract has been evaluated by electrochemical studies such as polarization. For Thermoactive alloy, polarization study lead ead to the conclusion that corrosion resistance of Thermoactive alloy decreases in the order AS + Neem Stick Extract > Neem Stick Extract > AS People implanted with orthodontic wire, made of Thermoactive alloy can take neem extract orally without any hesitation . Keywords: corrosion resistance, orthodontic wires, artificial saliva, extract of neem stick , Thermoactive alloy polarization study. study Inter Collegiate Meet- National Level Seminar on ““New New Perspective in Science and Technology”, th (NPST-2016), 7 October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, T Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 484-491 Editors: Dr S Rajendran, A Christy Catherine Mary

485

Can people implanted with Thermoactive alloy orthodontic wire clean their teeth with neem stick ? A.Christy Catherine Mary,P.Nandhini, U.Veeranagammal, S.Selvarathinam, Kohila, S.Rajendran, J.Jeyasundari,




2. Experimental Orthodontic wires made of Thermoactive alloy are used in the present study. The metal specimens were used as working electrode. They were immersed in Fusayamma Meyer artificial saliva whose composition is[8];


486



2.1Preparation of Neem Stick Extract Neem sticks were cut down from neem tree. They were dried in the shade. 50gms of the sticks was boiled with distilled water and the extract was made upto 100ml.


3. Result and Discussion 3.1 Analysis of Polarization curves Corrosion resistance of Thermoactive alloy in various test solution has been evaluated by polarization study. When corrosion resistance increases Linear Polarization Resistance (LPR) increases; Corrosion current(Icorr) decreases.

3.2.

Thermoactive alloy

The polarization curves of Thermoactive alloy immersed in various test solutions are shown in figure 1. The corrosion parameters namely Corrosion Potential (Ecorr), Tafel slopes Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 484-491 Editors: Dr S Rajendran, A Christy Catherine Mary

487


((bc= cathodic; (ba=anodic)), Linear Polarization Resistance (LPR) and Corrosion current(Icorr) are shown in table 2. Table2. Corrosion parameters of metals immersed in artificial saliva (AS) in the presence and absence of sugar cane juice, obtained by polarization study Metal

System

Thermo AS active Neem Stick Extarct alloy AS+ Neem Stick extarct

Ecorr mV vs SCE

bc mV/ decade

ba mV/ decade

LPR ohm cm2

-481

252

206

1854996

-572

145

229

3449865

-702

162

243

4160722

Icorr A/cm2 2.65x10-8 1.121x10-8 1.014x10-8

When Thermoactive alloy immersed in Artificial Saliva (AS), Linear Polarization Resistance (LPR) value is 1854996 ohm cm2. The Corrosion current(Icorr) is 2.65 x10-8A/ cm2 . The Corrosion Potential (Ecorr) is -481mV vs SCE. When Thermoactive alloy immersed in Neem Stick extract, Linear Polarization Resistance (LPR) value increases from 1854996 to 3449865 ohm cm2. The Corrosion current (Icorr) decreases from 2.65 x10-8 to 1.121x10-8 A/ cm2 . This indicates that Thermoactive alloy is more corrosion resistant in Neem Stick extract. Further the Corrosion Potential (Ecorr) value shifts from -481 to -702 mV vs SCE When Thermoactive alloy immersed in the system consisting of AS and Neem Stick extract, the LPR value further increases to 4160722 ohm cm2.the corrosion current decreases to 1.014x10-8 A/ cm2. This indicates the Thermoactive alloy is more corrosion resistant in AS + Neem Stick extract system than in Neem Stick extract system or AS system. Thus the polarization study leads to the conclusion that when Thermoactive alloy is immersed in various test solution, the decreasing order of corrosion resistance of Thermoactive alloy is as follows: AS + Neem Stick Extract > Neem Stick Extract > AS Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 484-491 Editors: Dr S Rajendran, A Christy Catherine Mary

488


This study reveals that people having orthodontic wires made of thermoactive alloy, can take neem extract orally without any hesitation . Because in this medium the corrosion resistance of thermoactive alloy increases.

Fig 1 Polarisation curve of Thermoactive alloy immersed in solution (a) Neem stick extract(b) Neem (c) AS

4. Conclusion 

Corrosion resistance of thermoactive Lalloy in artificial saliva (AS) in the absence and

presence of sugar cane juice has been evaluated by electrochemical studies such as polarization study. 

For thermoactive alloy polarization study and to the conclusion that corrosion resistance

of thermoactive alloy decreases in the order AS + Neem Stick Extract > Neem Stick Extract > AS People implanted with orthodontic wire, made of thermoactive alloy, can clean their teeth with neem stick without any hesitation . Because in this medium the corrosion resistance of thermoactive alloy increases. Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST-2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India. Int J Nano Corr Sci and Engg 3(4)(2016) 484-491 Editors: Dr S Rajendran, A Christy Catherine Mary

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Applications Of Uv-Visible Absorption Spectroscopy In Corrosion Inhibition Study N.Karthiga, S.Rajendran and P.Prabhakar

Applications Of Uv-Visible Absorption Spectroscopy In Corrosion Inhibition Study N.Karthiga[1], S.Rajendran[2] and P.Prabhakar[3] 1Department of Chemistry, SBM College of Engineering and Technology, Dindigul, India. Email: [email protected] 2 Department of Chemistry, St.Antony’s college of arts and sciences for women-dindigul 624 005,Tamil Nadu, India. Email: [email protected] 3PG and Research Department of Chemistry, APA College of Arts and Culture, Palani, India. Abstract UV-visible absorption spectroscopy and UV-visible reflectance spectroscopy have been used in various fields such as detection of impurities in food samples and estimation of various compounds. They have been used in corrosion inhibition study also. It is observed that the protective film formed on the metal surface consists of metal-inhibitor complexes.

1. INTRODUCTION Inter Collegiate Meet- National Level Seminar on “New Perspective in Science and Technology”, (NPST2016), 7th October, 2016- St Antony’s College of Arts and Sciences for Women, Thamaraipadi, Dindigul, India.


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Applications Of Uv-Visible Absorption Spectroscopy In Corrosion Inhibition Study N.Karthiga, S.Rajendran and P.Prabhakar UV spectroscopy is an important tool in analytical chemistry. The other name of UV (UltraViolet) spectroscopy is Electronic spectroscopy as it involves the promotion of the electrons from the ground state to the higher energy or excited state. UV spectroscopy is type of absorption spectroscopy in which light of ultra-violet region (200-400 nm.) is absorbed by the molecule. Absorption of the ultra-violet radiations results in the excitation of the electrons from the ground state to higher energy state. The energy of the ultra-violet radiation that are absorbed is equal to the energy difference between the ground state and higher energy states ( ∆ = ℎ ). Generally, the most favoured transition is from the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO). For most of the molecules, the lowest energy occupied molecular orbitals are s orbital, which correspond to sigma bonds. The p orbitals are at somewhat higher energy levels, the orbitals (nonbonding orbitals) with unshared paired of electrons lie at higher energy levels. The unoccupied or antibonding orbitals (pie*and sigma*) are the highest energy occupied orbitals. In all the compounds (other than alkanes), the electrons undergo various transitions. Some of the important transitions with increasing energies are:

→

∗