Fabrication of hydrophobic composite films by sol-gel process between POSS -containing fluorinated polyacrylate latexes and colloidal silica particles

Abstract

A novel hydrophobic composite films (POSS-FPA-SiO2) were prepared by directly physically mixing octavinyl polyhedral oligomeric silsesquioxane containing fluorinated polyacrylate latexes (POSS-FPA) with colloidal silica. Sol-gel processes were carried out on the surface of POSS with addition of co-solvent to enhance roughness and hydrophobicity of composite films. TEM photos revealed that colloidal silica particles had enriched and aggregated on the surface of POSS, the sol-gel processes of silica particles occurred to form raspberry-like structure particles. The average diameter data indicated that the aggregation of colloidal silica particles on the surface of POSS had increased the average diameter of the composite latexes. FT-IR spectra confirmed that two kinds of SiO bonds existed in the composite films, which one related to the SiO framework of POSS and the other obtained form the sol-gel processes. SEM and AFM images illustrated that the coarse structure obtained from the sol-gel processes had increased the roughness of the composite surface. The water contact angle (WCA) of composite films were found increasing as the sol-gel processes. TGA curves demonstrated that the composite films exhibited much better thermal stability than that of pure FPA and POSS-FPA films.