Robust Super-Repellent Anisotropic Silica Films by Emulsion-Based Sol–Gel Growth

Abstract

In this paper, anisotropic SiO2 with different morphologies were synthesized through an emulsion-based one-pot method by adding various silane coupling agents. Silane coupling agents affected the growth of silica nanostructures at the oil/water interfaces. Robust super-repellent film that showed great durability under different harsh conditions were obtained by bonding the self-assembled anisotropic silica nanostructures (ASN) film to substrate by the commercial acrylic adhesive. The film switched from superhydrophobic (157.1[Formula: see text] to superhydrophilic (0[Formula: see text] after being heat-treated at 500[Formula: see text]C. Further, silane treatment with addition of acid reduced the time of modification. Meanwhile, silane grafting density was improved and superhydrophobicity of calcinated ASN films was regenerated.