State Analysis of Water in Anion-Exchange Resins by Differential Scanning Calorimetry

Abstract

The state of water in anion-exchange resins of various anion forms was studied by differential scanning calorimetry (DSC). The amounts of non-freezing water molecules in both MR and Gel type resins were much the same in the order of F>OH>Cl>Br>I. The melting peak of the water in the Gel-type resins shifted to the high-temperature side in the order of I>Br>Cl>OH>F when the freezing water content of each ion form was equal. Moreover, the free water was detected in the I- form. These results indicated that the water molecules in the resins were strongly bound in the order of F>OH>Cl>Br>I.