Silica membranes were modified by fluorocarbon groups through acid-catalyzed co-hydrolysis and condensation reaction of tetraethylorthosilicate(TEOS) and trifluo- propyltriethoxysilane(TFPTES). The cross-sectional micrographs, pore structure and hydrophobic property of silica membranes were characterized by SEM, nitrogen adsorption, FT-IR and contact angle meter. The results show that the hydrophobic property of modified silica membranes is gradually enhanced, whereas the pore structure almost remains unchanged with the increase of TFPTES content. When the molar ratio of TFPTES/TEOS increases to 0.6, the modified silica membranes possess a water contact angle of 111.6°±0.5° and a desirable microporous structure, with a pore volume of 0.19cm3•g-1 and a pore size of 0.97nm.

Key words: Microporous membrane, Porous structure, Hydrophobic property