PREPARATION OF SOME INORGANIC PRECIPITATE MEMBRANES AND EVALUATION OFTHEIR MEMBRANE PARAMETERS

Electrical potentials developed across ferric and stannic arsenate mem branes separating various 1:1 electrolytes at different concentrations are reported. Various theories of membrane ion transport, based on no n-equilibrium thermodynamics, have been applied to potentiometric meas urements for the evaluation of effective fixed charge density and sele ctivity of the ferric and stannic arsenate precipitate membranes. Theo ries for the salt concentration dependence of bi-ionic potentials as p roposed by Tasaka et al. and Toyoshima and Nozaki have been compared t o obtain a relationship for the evaluation of the theoretical values o f bi-ionic potentials. The close agreement between these theoretical v alues and the observed ones confirms the applicability of the derived relationship to the membrane electrolyte systems used in this investig ation.