This study describes the facile preparation of poly(vinyl alcohol) (PVA)/polyethersulfone (PES) composite membranes by interfacial reaction technique, aiming at acquiring the improved structural and operational stability of the resulting membranes. The effect of interfacial crosslinking agent and hydrophilicity of support layer on the interfacial adhesive strength and pervaporation performance of composite membranes were investigated. The optimal recipe for PVA/PES composite membrane preparation was as follows: PES support layer was treated with 0.1 wt.% borax aqueous solution, fully dried and then immersed into 2 wt.% PVA aqueous solution. The resulting PVA active layer was 1-1.5 mu m thick after twice dip-coating. The as prepared PVA/PES composite membrane exhibited high separation factor of over 438, high permeation flux of 427 g m(-2) h(-1) for 80 wt.% EG in the feed at 70 degrees C and desirable structural stability. It could be derived that adoption of interfacial reaction would be an effective method for preparing the composite membranes suitable for large-scale dehydration of ethylene glycol/water mixture. (c) 2008 Published by Elsevier B.V.