A model equations for voltage concentration boundary layers effect in a single polymeric membrane electrochemical cell.

The model equation for voltage concentration boundary layers effect (vCBLE) across an isotropic polymeric membrane is presented for cases in which the membrane separates unstirred electrolytic solutions at different concentrations. This model equation for binary electrolyte solutions and cell with a horizontally mounted membrane was tested. The vCBLE as a function of ratio solution concentrations and gravitational configuration was calculated. Calculations were made for the case when on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2.5 x 10(-3) mol x l(-1) (Ch). Their density was greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that voltage concentration boundary layers effect depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by Rayleigh number and that with a increase of value of this number the type of characteristic is changing v(CBLE) = f(Ch/Cl)RC=const.