Pervaporation properties of thermally modified chitosan films

Pervaporation properties of chitosan films in a basic form prepared from thermally modified chitosan acetate in a salt form with respect to aqueous-organic media are studied. It is found that thermally treated films of smaller surface areas have higher permeability and selectivity than the initial chitosan film. A tenfold increase in the membrane surface area leads to a manyfold decrease in a permeate flux density through a thermally treated membrane as compared with an initial membrane and to the appearance of inverse selective permeability upon variations in a liquid phase composition. The results obtained are compared with the previous data. It is concluded that swelling complex polymeric materials are characterized insufficiently for explanation of specific transport properties with respect to low-molecular-weight substances that are capable of varying the supramolecular organization of a polymer.