Environment-responsive membranes, suitable for carrying out hydrophobic interaction membrane chromatography (HIMC) were prepared by modification of a commercial hydrophobic microporous polyvinylidene fluoride (PVDF) membrane with a salt-responsive hydrogel composed of poly(N-vinyl lactam) cross-linked with bisacrylamide. These modified membranes were moderately hydrophobic in the presence of lyotropic salts but were quite hydrophilic in their absence. The membranes were characterized in terms of their mass gains after modification as well as their contact angles. These new membranes were found to be suitable for carrying out monoclonal antibody purification. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.