Effect of Nature and Charge of Counterions and Co-Ions on Electrotransport Properties of Heterogeneous Anion Exchange Membranes

A comprehensive characterization of heterogeneous anion exchange MA-40 and MA-41 membranes, differing in the nature of functional groups and the ion-exchange capacity (3.32 and 1.41 mmol/g_dry, respectively), was carried out. The MA-40 membrane contains low basic secondary and tertiary amino groups, while the MA-41 membrane contains predominantly quaternary ammonium bases. Concentration dependences of conductivity and diffusion permeability, current-voltage curves were obtained, and the transport-structural parameters of a microheterogeneous model of membrane in solutions of different natures (salts and acids) containing singly and doubly charged cations and anions (sodium and calcium chlorides, sodium sulfate and sulfuric acid) were determined. The effect of counterions and co-ions on the electrotransport properties of the studied membranes was revealed; it was shown that changes in their properties are determined not only by the nature of the electrolyte but also by the value of the ion-exchange capacity of the samples, as well as the nature of their functional groups.