Pore Structure and Hydrophobic Property of Ethylene-modified Microporous Silica Membranes

Ethylene-modified microporous silica membranes were prepared by acid catalysed cohydrol- ysis and condensation reaction of tetraethylorthosilicate(TEOS) and ethylenetriethoxysilane (TEVS) in ethanol and characterized by means of N_2 adsorption,TG,NMR and contact angle meter.The re- sults show that the modified materials remain a desirable microporous structure with a pore width centered at 0.5-0.7nm,and that the hydrophobic property of modified silica membranes is considerably improved due to the gradual replacement of hydrophilic silanol by hydrophobic ethylene on the surface with increasing molar ratio of TEVS/TEOS.