Bio-inspired Nanoarchitectonics of Re-entrant Geometries toward Transparent Omniphobic Surfaces

Abstract

Omniphobic coatings provide liquid repellent surfaces by trapping air in their micro nanostructured surfaces and show promise for various applications. However, it remains a formidable challenge to fabricate such coatings in a controllable way. Here, we report facile construction of a series of re-entrant geometries that resemble the skin of springtails. By rationally controlling the parameters of dip-coating operation assisted by a colloidal crystal template, three elaborate structures in the morphology of re-entrant triangular posts, concave quadrilateral posts, and circular holes have been constructed. These nanostructured surfaces exhibit excellent omniphobicity that repel liquids with a wide spectrum of polarity. Impressively, the honeycomb porous re-entrant structures also demonstrate exceptionally high light-harvesting performance derived from their excellent scattering ability. Through this proof of concept, our simple, controllable, and scalable method shows great potential in designing highly efficient omniphobic surfaces for practical solar energy applications.

Engineered Sustainable Omniphobic Coatings to Control Liquid Spreading on Food-Contact Materials

“…Neither superhydrophobic surfaces nor SLIPSes can maintain a well-developed interface against oil and are simply wetted by attacking oils because the surface tension of oils (∼20 mN m –1 ) is much lower than that of water (∼72 mN m –1 ). Several recent efforts have explored the critical role of re-entrant curvature in designing superamphiphobic surfaces that display both superoleophobic and superhydrophobic characteristics. − Despite the remarkable progress in replicating the re-entrant topography into several human-made surfaces, an accelerated flow or underestimated pressure can still destabilize the balanced air pockets between the topographical features. This is because the current bioinspired structures have a narrow depth with an uncontrolled overhang structure, which typically results in less-than-desirable tolerance against pressure .…”