Comparison of the transport properties of normal and expanded forms of a cation-exchange membrane. Part 3.—Application of irreversible thermodynamics and Nernst-Planck theories to membranes in concentrated NaCl solutions

Abstract

The Onsager mobility and frictional coefficients for the normal and expanded membranes have been calculated when the external solution was 1.0 M NaCl. The validity of a number of methods of approximation of minor coefficients is examined. The results have been reproduced using a ternary electrolyte calculation in which mobility coefficients for the salt-free membrane were combined with those of aqueous sodium chloride. Calculated transport measurements agree well with those obtained experimentally. Finally the validity and probable errors of the Nernst-Planck theory are examined.