Limiting current densities in electromembrane systems with carboxyl-containing polyamidoimide membranes

Voltammetric characteristics of electromembrane systems with carboxyl-conta ining polyamidoimide membranes in 0.01 M solutions of sodium and hydrogen c hlorides are studied using a rotating membrane disc. The limiting current d ensity increases with the decrease in the exchange capacity and an increase in the generation temperature and imidization degree of membranes, due to variations in their structures. The difference in the structure of membrane s with various exchange capacities is proved by the standard porosimetry me thod. The distinguishing feature of the limiting state in the HCl solutions is that the generation of the hydrogen and hydroxyl ions in the near-surfa ce layer occurs long before its concentration exhaustion.