Membranes of polyacrylonitrile (PAN) and polyacrylonitrile-graft-poly(ethylene oxide) (PAN-graft-PEO) blends were prepared by casting from N,N-dimethyl formamide solution The membrane performance with different PEO branch content in the PAN-graft-PEO was evaluated for separation of water/ethanol mixtures by pervaporation.