Trimesoyl chloride crosslinked chitosan membranes for CO2/N2 separation and pervaporation dehydration of isopropanol

Crosslinked chitosan membranes were prepared from interfacial crosslinking of chitosan membranes in trimesoyl chloride (TMC)/hexane. A higher degree of swelling was observed for the membrane with a higher degree of crosslinking when swollen in water at room temperature. Membranes were characterized with DSC and TGA, and a two-stage thermal decomposition mechanism was proposed. Pure gas permeation was performed with CO2 and N-2 at room temperature, and CS-TMC-2 membrane had the best selectivity towards CO2/N-2, with CO2 permeability of similar to 163 Barrers and the ideal separation factor of similar to 42. Pervaporation was carried out for dehydration of isopropanol with the unconditioned and conditioned membranes, and CS-TMC-3 membrane showed the best pervaporation properties. The crosslinking-induced changes in the relaxation behavior and mobility/packing properties of polymer matrices were attributed to the changes in pervaporation and gas separation performances. (C) 2007 Elsevier B.V. All rights reserved.