TABLE OF CONTENTS After preparing the ion exchange membranes, their properties and characteristics have to be evaluated according to the purpose of the experiment and their applications. When commercially available ion exchange membranes are industrially used, however, the basic properties of the membranes should be fully evaluated to derive excellent properties from the membranes. In this chapter, the basic properties of ion exchange membranes that need to be evaluated are explained and then the methods used to measure each property are explained.
Also, because ion exchange membranes have polar groups (cationic and/or anionic charge) in a non-polar polymer matrix, which is different from other polymer membranes, they have a particular microstructure. Knowledge of this microstructure is necessary to use the ion exchange membranes efficiently. Many studies on the microstructure have been performed both from an academic viewpoint and in terms of industrial requirements. Representative studies are described here.
Ion exchange membranes differ from other polymer films in having charged groups, anionic and/or cationic, that are fixed on the polymer film. The particular properties of the ion exchange membrane arise from the existence of the charge. Their characteristics are primarily decided according to the amount (ion exchange capacity) and species of the charged groups and their distribution in the membrane, and the amount of water molecules adsorbed on the membrane due to these groups (water content).
According to the application of the membrane, the characteristics to be evaluated are different. Ion...
