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 N2 at room temperature, and CS-TMC-2 membrane had the best selectivity towards CO2/N2, with CO2 permeability of ∼163 Barrers and the ideal separation factor of ∼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.