Penguin feathers may be secret to effective anti-icing technology

Phys.org  October 24, 2022 The body feathers of perpetually ice-free penguins are very good natural examples of anti-icing surfaces, which use two different mitigation strategies for the two disparate problems – water adhesion and ice adhesion. Researchers in Canada constructed the form of the feather’s wire-like structure and decorated it with superimposed nanogrooves by laser micromachining fine woven wire cloths. Post-processing techniques also allowed them to isolate the role of surface chemistry by creating both hydrophilic and hydrophobic versions of the synthetic anti-icing surfaces. Their results showed that water-shedding and ice-shedding characteristics are indeed derived from different physical functions of […]

Water can’t touch this sanded, powdered surface

Phys.org  August 4, 2022 Water droplets must have large apparent contact angle (CA) (>150°) and small CA hysteresis (<10°) on hydrophobic surfaces. Previous research usually involved complex fabrication strategies to modify the surface wettability. Researchers at Rice University developed a simple technique that involves sandpaper and a selection of powders which are sanded into the surface. They applied the technique on a variety of surfaces (Teflon, polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polydimethylsiloxane) with a variety of powder additives. These included laser-induced graphene fiber, turbostratic flash graphene, molybdenum disulfide, Teflon, and boron nitride. A variety of aluminum oxide sandpapers were […]

UBCO researchers create liquid-repelling substance that works on all surfaces

EurekAlert  July 15, 2020 Omniphobic–all-liquid repellent–films can repel a broad range of liquids, but the applicability of these coatings has always been limited to silicon wafers or smooth glass. Researchers in Canada have developed a facile procedure to generate an omniphobic coating on any surface, including metals, paper, ceramics, etc. The process involves depositing an ultra smooth, silicon wafer-like silica layer and then treating this layer with a highly reactive chlorosilane, which grafts polydimethylsiloxane chains onto the surface. Negligible contact angle hysteresis (≤1°) for various liquids, including ultralow surface tension oils, alcohols, and fluoro-solvents, was achieved on many different substrates […]