Formation of electric triple layers by interdiffusion of two electrolytes

Abstract

The interdiffusion of two electrolytes has been investigated by digital computer simulations. Concentration profiles and electric field strength profiles which are invariant under a Boltzmann-transformation seem to be asymptotically stable. The diffusion potential against time curves are well fitted by a single exponential or a sum of two exponentials with relaxation times around 1/2h when the initial conditions correspond to an error-function zone of length 1 cm. A field reversal effect corresponding to an electric triple layer was observed for CaCl₂ at high concentration against HCl at low concentration. Associated with the field reversal is a hump in the H⁺-profile with maximum in the point of zero field strength.