Microporous anion-exchange membranes were prepared by immobilizing a cationic polymer like poly(dimethyldimethylene piperidinium chloride) (PDMeDMPCl) in a network made of poly(vinyl alcohol) (PVA). PVA was crosslinked by dibromoethane vapor at 140 degreesC to stabilize the membrane structure. The membrane morphology and properties were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), and the electrolyte transport measurements. From the results of the analyses of the obtained data, we proposed a new mechanism of membrane formation in which the membrane micropores are generated by the solvent evaporation from the cast polymer blend solution. (C) 2003 Elsevier B.V. All rights reserved.