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

Abstract

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.