SECTION TITLE
COATING TECHNOLOGY
SUPERHYDROPHOBIC SURFACES A
Preventing corrosion, bacterial growth and chemical fouling on underwater surfaces
erophilic surfaces – those that rely on or are only active in the presence oxygen – immersed underwater trap films of air known
as plastrons. Utilising the protective effects of plastrons could lead to the development of underwater superhydrophobic surfaces capable of preventing corrosion, bacterial growth, the adhesion of marine organisms, chemical fouling and other harmful effects of liquids on surfaces. Material scientists have been attempting to harness the protective effects of plastrons for decades, however they have typically been considered impractical for
The Argyroneta Aquatica spider lives its entire life underwater thanks to millions of water repellent hairs that trap air around its body to create an oxygen reservoir
underwater engineering applications due to their meta-stable performance. Tus far, plastrons have proved highly unstable under water – keeping surfaces dry for only a matter of hours in the lab. Tis could all be about to change,
however, thanks to a combined team of researchers led by the Harvard John A Paulson School of Engineering and Applied Sciences (SEAS), the Wyss Institute for Biologically Inspired Engineering at Harvard, the Friedrich- Alexander-Universität Erlangen-Nürnberg in Germany and Aalto University in Finland. Te team has successfully
developed a superhydrophobic surface with a stable plastron that can reportedly last for months underwater, opening up a range of applications in biomedicine and industry.
SUPERHYDROPHOBICITY EXPLAINED Superhydrophobic materials are highly hydrophobic and extremely hard to ‘wet’. Generally, this type of surface is defined by having the static water contact angle above 150° and contact angle hysteresis less than 5°. Superhydrophobic coatings are often found in nature, appearing on
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