Current-voltage characteristics of asymmetric bipolar membranes
Keywords:
current-voltage characteristic, asymmetric bipolar membrane, surface modification, bilayer membrane, mathematical modeling.Abstract
A mathematical model describing the transfer of hydrogen and hydroxyl ions and salts through
asymmetric bipolar membranes is developed. The model accounts for a chemical reaction - dissociation of
water at the boundary between an anion and cation-exchange layers. The chemical reaction causes the
occurrence of the bipolar region overvoltage, which leads to a deviation of the current-voltage characteristics
of the bipolar membrane from linear. Experimentally and theoretically demonstrated bifunctionality of the
asymmetric bipolar membranes - their ability to simultaneous selective ion transport of salt and water
dissociation products. In dilute solutions water dissociation occurs with high current efficiency, and in the
concentrated - a simultaneous transfer of salt ions as well as products of water dissociation is observed.
