A hydrophilic polymeric/ceramic polyelectrolyte composite pervaporation membrane was prepared by free-radical graft polymerization of poly (1-vinylimidazole) (PVI) onto the microporous ceramic membrane and protonation. The mineral support was pre-coated with active silica and pretreated by silane couple agent to introduce vinyl end group for the grafting. By means of FT-IR and TGA the chemical composition and grafting yield on the powder silica gel were measured. The membrane morphology was observed with SEM. The effect of operation conditions on the pervaporation performance of the membrane was also studied. The results showed that the composite membrane was very permeable and selective to water for the dehydration of the alcohol and organic acid. According to the abnormal variation of membrane permeation with operation temperature and SEM image it suggests that the grafting took place inside the pores of the ceramic supports

Key words: pervaporation, polymer/ceramic composite membrane, poly(1-vinylimidazole), cationic polyelectrolyte