Preparation of super-hydrophobic silica films with visible light transmission using phase separation

Abstract

Super-hydrophobic silica-based thin films were prepared by means of sol–gel processing, a phase separation and self-assembly (SA). Desired surface roughness was obtained by combining a sol HCl as a catalyst, a another sol NH4OH as a catalyst and a phase separation of tetraethyl orthosilicate (TEOS) induced by the addition of poly(acrylic acid) (PAA). The microstructure of the films was hill-like on the proper degree of the phase separation. Moreover, after a further modification with a self-assembled monolayer (SAM), the film changes its wetting properties and turns hydrophobic.