On the Schroeder paradox for ion-exchange polymers

• Published in: Colloid journal of the Russian Academy of Sciences Vol. 78; no. 6; pp. 795 - 799
• Main Authors: Roldughin, V. I., Karpenko-Jereb, L. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-11-2016; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Ion exchange; Ion exchange resins; Polymer Sciences; Polymers; Surfaces and Interfaces; Swelling; Thin Films; Water
• ISSN: 1061-933X; 1608-3067
• DOI: 10.1134/S1061933X16060132

The known Schroeder paradox, i.e., a difference in the degree of swelling of ion-exchange polymers at equilibrium with liquid water and its vapor, has been discussed. It has been noted that there is no paradoxicality in this phenomenon. An example of different “swelling” based on trivial physical considerations has been presented. A simple mechanism has been proposed for increased swelling of an ion-exchange polymer immersed in liquid water, this mechanism being associated with the action of the Maxwell stresses at a polymer/electrolyte interface. The predicted values of the “excess” swelling have been shown to correspond to the data of real experiments.