Facile fabrication of fluorine-silicon-containing poly (styrene-acrylate)/SiO2 hydrophobic composites by combining physically mixing and sol-gel process

Novel hydrophobic composites (FS-PSA/SiO2) were prepared by directly physically mixing fluorine-silicon-containing poly (styrene-acrylate) latexes (FS-PSA) with colloidal silica. Sol-gel processes were carried out between silica particles and silanol groups on the surface of poly (styrene-acrylate) latexes to enhance the roughness and hydrophobicity of composite films. TEM photos revealed that FS-PSA latexes exhibited a clear core-shell structure, and the intermolecular hydrogen bonding guaranteed the uniform dispersion of silica particles. The average diameter data indicated that the copolymerization and sol-gel process had all increased the average diameter of the composite latexes. FTIR and XPS spectra confirmed that two kinds of Si-O bonds existed in the composite films, of which one was related to the Si-O groups of colloidal silica while the other was related to the Si-O-Si groups obtained from the sol-gel processes. SEM and AFM images revealed that the sol-gel processes had increased the roughness of the composite films. The water contact angle (WCA) of the composite films were found to increase with the copolymerization and sol-gel processes. Thermogravimetric analysis (TGA) curves demonstrated that the FS-PSA/SiO2 composite films exhibited much better thermal stability than the PSA and FS-PSA films.