Preparation and Properties of Monovalent Anion Permselective Anion Exchange Membranes

In order to prepare a monovalent permselective anion exchange membrane, the surface of a precursor membrane, which was prepared from a membranous copolymer of chloromethylstyrene (CMS) and divinylbenzene (DVB) in the presence of poly(vinyl chloride), was treated with various amino compounds; the chloromethylphenyl groups in the membrane were then reacted with trimethylamine so as to introduce (trimethylammoniomethyl)phenyl groups. The anion exchange membranes which were modified with tetraethylenepentamine and 4-vinylpyridine showed a chloride anion permselectivity versus that of a sulfate one in electrodialysis. It was thought that the reaction between these amines and the chloromethylphenyl groups formed a higher crosslinking structure on the surface of the membrane.