Study on the Factors Affecting the Hydrophobic Property of Silica Membranes

Various hydrophobic groups were used to modify the silica membranes by the co-hydrolysis and condensation of 1,2-bis(triethoxysilyl)ethane and alkylsilanes. The hydrophobic property and surface roughness of silica membranes were characterized by water contact angle measurement and atomic force microscope, respectively. The results show that the hydrophobic property of modified silica membranes increases with increasing concentration of alkylsilane in the mixture, increasing surface roughness and increasing length of carbon chain in the alkyl groups.