Omniphobic liquid-like surfaces are a new type of liquid-repellent surface that offer many technical benefits over traditional approaches. They have molecular layers that are highly mobile yet covalently tethered to the substrate, giving solid surfaces a liquid-like quality that acts like a layer of lubricant between the water droplets and the surface itself. In new research, a team of scientists led by Aalto University used a specially-designed reactor to create a liquid-like layer of molecules, called self-assembled monolayers, on top of a silicon surface.
Anti-wettability, the ability of a surface to repel liquids, is crucial to many aspects of daily life and industry.
Advanced anti-wetting surfaces that can passively remove liquids have attracted increasing interest because of their potential applications in anti-fouling, anti-icing, drag reduction, membrane separation and enhanced heat transfer.
Inspired by biological surfaces and benefiting from progress in nanofabrication techniques, a large number of advanced liquid-repellent surfaces have been developed since the 1990s, including air-mediated superhydrophobic surfaces (SHPSs), superoleophobic surfaces (SOPSs) and liquid-mediated slippery lubricant-infused porous surfaces (SLIPSs).
Air-mediated liquid-repellent surfaces (such as SHPSs and SOPSs) rely on a trapped air layer in the structure of the surface to repel liquids.
Stable trapping of the air layer generally requires the combination of low-surface-energy surface chemistry and specific surface structures, such as hierarchical micro/nanostructures for SHPSs or reentrant structures for SOPSs.
Alongside the progress of air-mediated surfaces and liquid- mediated surfaces, a new research field has bloomed: the development of omniphobic liquid-like surfaces by covalently grafting highly flexible polymer brushes or alkyl monolayers onto smooth solid surfaces.
“Our work is the first time that anyone has gone directly to the nanometer-level to create…
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