Hybrid materials were prepared incorporating silica networks by the sol-gel process into the poly(amide-b-polyether) block copolymer PEBAX((R)). PEBAX((R))/ silica hybrids were characterized by transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, and X-ray diffraction. The pervaporation of phenol from dilute aqueous solutions through hybrid membranes was investigated. Films prepared with lower silica contents showed better dispersed inorganic networks and were more selective in the pervaporation of phenol/water solutions. Films prepared with higher silica contents had a clear phase-separated morphology with lower performance in pervaporation. (C) 2001 John Wiley & Sons, Inc.821178185