Fabrication of air-permeable superhydrophobic surfaces with excellent non-wetting property

Abstract

The superhydrophobic surface (SHS) is attractive for drag reduction, anti-icing, and anti-fouling, but its insufficient non-wetting property has limited its applications. This study aims to fabricate, characterize, and evaluate SHS with excellent non-wetting properties. The SHS is fabricated via electrochemical treatments and silanization, changing superhydrophilic porous titanium substrates into superhydrophobicity. Hierarchical micro/nano-structures and low-energy coating are created on substrates with interconnected micropores, resulting in high static contact angle (SCA) air-permeable SHS (i.e. SCA = 152.5°). The non-wetting property of the SHS, characterized by the interfacial reflection intensity, is reversibly recovered in the turbulent water flow test. An excellent non-wetting property is achieved by actively minimizing the pressure difference across the surface.