Preparation of Chitosan and Modified Chitosan Membranes for Ultrafiltration and Dialysis and Determination of Membrane Properties

Chitosan and modified chitosan membranes for ultrafiltration and dialysis were prepared by the casting method with various acids as the salt-forming agents. Sulfamic acid and glutamic acid, as well as some monocaboxylic acids, were found to be excellent salt-forming agents. To improve the solvent-resistant properties of the chitosan membranes, two chemical procedures for the modification were employed. One is the cross-linking of the membrane by the photochemical reaction with an aromatic diazido-compound, and the other is chemical modification of chitosan by carbamoylation. The latter procedure was especially effective; thus a membrane which exhibited high preformance and high solvent-resistance could be fabricated.