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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