Transport studies of parchment supported model membrane: Test of bi-ionic potential theories and evaluation of membrane selectivity for metal ions

Abstract

The bi-ionic potential (BIP) values across the parchment supported mercuric sulphide membrane with various combinations of 1:1 electrolytes at different concentrations have been measured. Theoretical values of BIP have been

calculated using the BIP theories developed recently by Toyoshima <i>et al.</i>¹¹<i> </i>and Tasaka <i>et al.</i>¹²<i> </i>based on the principles of non-equilibrium thermodynamics. Comparison of experimental and theoretical BIP values shows that theoretical equations of BIP are applicable to the parchment supported membrane. Membrane conductivity in contact with a single electrolyte has been experimentally determined to evaluate the selectivity of the membrane using the predetermined values of intramembrane mobility ratio. The selectivity sequence of the membrane is found to be.

K⁺ ˃ Na⁺ ˃ Li⁺