Electrochemical properties and structure of ion-exchange membranes upon thermochemical treatment

• Published in: Russian journal of electrochemistry 2014-08, Vol.50 (8), p.789-797
• Main Authors: Vasil’eva, V. I., Akberova, E. M., Shaposhnik, V. A., Malykhin, M. D.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Electrochemistry; Physical Chemistry
• ISSN: 1023-1935; 1608-3342
• DOI: 10.1134/S102319351408014X

The effect of temperature-induced morphological changes on the electrochemical and physicochemical properties of the heterogeneous sulfo cation-exchange membrane MK-40 in aqueous, alkaline, and acidic media is subjected to comparative analysis. The deviation between the surface and volume microstructure of swollen membrane samples after their chemical conditioning and thermochemical treatment are visualized by a scanning electron microscope. The porosity and the fraction of the ion-exchange component in membranes subjected to heating in water and aggressive media are observed to increase more noticeably in their surface layer as compared with their volume. The maximum effect thus modified structural characteristics on the transport (conductivity, diffusion permeability, selectivity) and physicochemical (exchange capacity, water content, density, linear sizes) properties is observed for MK-40 membrane samples when heated in a sulfuric acid solution. The effect of thermal destruction of inert polymers (divinylbenzene, caprone) involved in the membrane composition on the transport characteristics is revealed.