Carboxymethyl chitosan (CMCS)/polysulfone (PS) hollow-fiber composite membranes were prepared through glutaraldehyde (GA) as the crosslinking agent and PS hollow-fiber ultrafiltration membrane as the support. The permeation and separation characteristics for dehydration of isopropanol were investigated by the pervaporation method. Pure chitosan, carboxymethyl chitosan, and crosslinked carboxymethyl chitosan membranes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) to study the crosslinking reaction mechanism and degree of crystallinity, respectively. The effects of feed compo- sition, crosslinking agent, membrane thickness, and feed temperature on membrane performance were investigated. The results show that the crosslinked CMCS/PS hollow-fiber composite membranes possess high selectivity and promising permeability. The permeation flux and separation factor for isopropanol/water is 38.6 g/m(2)h and 3238.5, using 87.5 wt % isopropanol concentration at 45 degrees C, respectively. (c) 2006 Wiley Periodicals, Inc.