The organic-inorganic hybrid membranes were prepared by co-hydrolysis and co-condensation of gamma-glycidyloxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS) in poly(vinyl alcohol) (PVA) aqueous solution. The effect of the relative molar content of GPTMS on the physicochemical properties of membranes, such as morphology, thermal, mechanical and swelling properties, as well as pervaporation performance for dehydration of ethylene glycol (EG) aqueous solution were investigated. The appropriate amount of GPTMS could effectively prevent the aggregation of silica particles and obtain more homogeneous distribution of silica particles throughout PVA matrix, significantly optimizing the interfacial interaction of silica-silica and silica-PVA. Furthermore, tensile measurements revealed that toughness of the hybrid membranes was considerably enhanced. The hybrid membranes with fixed mass ratio 1: 1 (GPTMS + TEOS to PVA) and 33% of relative molar content of GPTMS exhibited the highest permselectivity of 714 with a permeation flux of 60 g/m(2) h at 70 degrees C for 80 wt.% EG aqueous solution. (c) 2006 Elsevier B.V. All rights reserved.