Industrial anion exchange mechanism

As mentioned in Chapter 5, ion exchange membranes have no permselectivity for specific ions. If an ion exchange membrane had permselectivity for specific ions, separation of ions with the same charge would be possible by electrochemical potential, which would be a remarkable contribution to industry. In the anion exchange membrane, permselectivity between anions is reported to be controlled by the difference of the hydrophilicity of the membrane. New methods other than controlling the hydrophilicity of the membrane should be found on the basis of another mechanism. 

Common diaphragm materials used in commercial electrolytic cells are porous ceramics, asbestos, and microporous plastics, but they all suffer from poor mechanical strength and availability in limited sizes and shapes. It was only after the availability of the highly stable perfluori-nated ion-exchange membranes that the problems of cell separators for industrial production were solved. These ion-exchange membranes allow only cation or anion (with water) transport between electrode chambers. 

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