Evaluation with the marine fouling barnacles. (Amphibalanus amphitrite, 2 weeks). Evaluation with the marine fouling mussels. (Geukensia demissa, 3 days).
Mimicking a lotus leaf hydrophobicity at home: a facile method to prepare durable ultrahydrophobic/slippery titanium Alexander B. Tesler,1,2,3 Stefan Kolle,2 Caitlin Howell,1,2 Shane Stafslien4 and Joanna Aizenberg1,2 1School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA 2WYSS Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA, USA 3Materials and Interfaces, Weismann Institute of Science, Rehovot, Israel 4Center for Nanoscale Science and Engineering, North Dakota State University, Fargo, ND, USA
Abstract
Ultra hydrophobic Ti Biological model: Nepenthes plant
A simple, nontoxic and inexpensive method to prepare mechanically robust surfaces that repel a variety of liquids and solids has immediate relevance in many industrial applications. Inspired by the Nepenthes pitcher plant, SLIPS surfaces function under high-pressure conditions, instantly self-heal imperfections, repel ice nucleation, and are ultrarepellent to pure and complex fluids as well as solids. In this research, I developed an inexpensive and environmentally friendly electrochemical process to form a porous and mechanically robust layer of hierarchical micro/nanostructured titanium oxide without the use of any post-deposition treatments. These surfaces are and mechanically robust ultra-hydrophobic (CA=180⁰, CAH=0⁰). When converted to SLIPS, these surfaces show exceptional anti-biofouling performance competing well with state-of-the-art antibiofouling coatings.
Characterization of deposited films
100 µm
HR-SEM SLIPS concept
PNAS, 101, 14138
EDS
Titanium U-SHS/SLIPS
8”
Wetting characteristics of U-SHS Ti Tilting angle is
Mirror-like U-SHS Ti substrates
Before
Turbulent flow stable
Hot
U-SHS Ti surfaces repel blood U-SHS Ti surfaces repel blood adhesion
Sand abrasion setup
Uniform U-SHS
0o
Before
Cold
After
CAH
4”
U-SHS Ti after exposure to blood
Whole porcine blood was used in the experiment, the blood was dropped on the surface, left for 1 min then washed with DI water. Tilting angle during the wash is 0o.
After
Antimicrobial Ti
Staphylococcus aureus biofilm adhesion
Candida albicans biofilm adhesion Bare
U-SHS
Bare
UH
SLIPS
SLIPS
U-SHS/SLIPS Ti prevents marine bio-fouling Evaluation with the marine bacterium (Cellulophaga lytica, 24 hours)
Evaluation with the marine fouling microalgae (Nitokra incerta, 48 hours)
Evaluation with the marine fouling barnacles (Amphibalanus amphitrite, 2 weeks)
Evaluation with the marine fouling mussels (Geukensia demissa, 3 days)
Evaluation with the green algae fouling (Chlamydomonas reinhardtii, 1 week) SLIPS
SHS
Before harvesting
After harvesting
Performance of Intersleek 700
Performance of Intersleek 900
Performance of Intersleek 1100 SR
• The absorbance value reported is directly proportional to the amount of biofilm on the coating surfaces
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None of the six barnacles reattached to the coating surface. All of the reattached barnacles exhibited substantial shell breakage/damage during force gauge removal.
*
All six mussels did not attach to the coating surface