Model for Electro‐osmosis in Fixed‐Charge Systems

Abstract

To a fixed‐charge lattice model previously employed to investigate ionic mobility in a system with no bulk flow, we have added crude hydrodynamicboundary conditions which make possible a solution of the appropriate Navier—Stokes equation in the presence of an external electric field. The resulting flow, electro‐osmosis, is strongly dependent on the concentration of neutral salt present, attaining a maximum in the absence of salts. The gradual transition from Poisseuille parabolic flow to ``plug'' flow as salt concentration or fixed‐charge density increases is explicitly demonstrated for the model.