Solvent-Free Synthesis of a Superamphiphobic Surface by Green Chemistry

Abstract

A superamphiphobic surface having both water and oil repellence was prepared by applying a solvent-free surface coating method using liquid-CO2 in the scope of “green chemistry”. Poly(perfluoroalkyl ethyl acrylate) homopolymer was synthesized by a free radical polymerization in supercritical CO2 medium. This polymer was dissolved in liquid-CO2 containing hydrophilic nanosilica particles in a stirred stainless steel reactor at room temperature under a low CO2 pressure. The polymer/nanosilica dispersion was used to coat glass slides located horizontally in a stainless steel tube by using the “free meniscus coating” method. A series of superamphiphobic coatings were formed under different coating conditions with the variation of polymer/nanosilica concentrations, the types of nanosilica powders, system pressures, and degassing flow rates. The highest apparent water contact angle was 173° and the hexadecane contact angle was 169° on these superamphiphobic hybrid coatings with roll-off angles that were <7°. Su...