Relationship between membrane potential and electrolyte uptake by ion‐exchange membranes

Abstract

synopsisElectrical potentials arising across three cation-selective membranes of low water content when they separate solutions of different concentration of the same NaCl electrolyte have been messured at 25°C. Also, electrolyte uptake by these membranes when they are in equilibrium with different soutions of NaCl has been estimated. These data together with the apparent membrane transport number derived from membrane potential have been used to check a simple relation given by Lakshminarayanaiah.

Ion selective electrodes, potentiometry, and potentiometric titrations

“…(669). Conductivity measurement methods (340), conductivity of polystyrene sulfonate (990), transport processes at varying applied voltages (408), current-voltage curves for BaSOi membranes (389) and solvent uptake and transport in ion exchange resin membranes (512) and in clay membranes (3) have been reported. Practical membrane potential measurements with synthetic cation exchangers have been noted (343,349,546).…”

Studies with model membranes. XXII. Evaluation of thermodynamic parameters and testing of theories of membrane and bi‐ionic potential based on nonequilibrium thermodynamics

“…The expressions for the activities and mobilities of small ions in the membrane are given by Equation (12) for the bi-ionic potential may be rewritten in the following form: (16) where to and EL are the values o f t in the membrane phase at x = 0 and x = L and qo and q~ are the corresponding values of q; t and q are the reduced concentrations, defined by E = (CAPOX) + CAP/(CAP + CBP) and 7 = (Csp/OX) + CBP/(CAP + CBP).…”