ELCTROOSMOSIS OF THE 2ND-KIND NEAR THE HETEROGENEOUS ION-EXCHANGE MEMBRANE

The features of concentrated polarization by an electric current passi ng through an ion-exchange membrane, with heterogeneous ionic conducti vity, are considered in this paper. A space charge appears inside the concentrated polarization zone caused by a strong electric held. In th e case of a surface with nonuniform conductivity, the tangential to th e surface component of electric field occurs. The action of the tangen tial component on the induced space charge produces electro-osmotic wh irlwinds, which change the main characteristics of the concentrated po larization and increase the current through the membrane. The peculiar ities of the polarization processes are analyzed for laminar and turbu lent flows of liquid along the interface. It has been shown that a com bination of electro-osmotic convection with turbulent pulsation leads to a significant rise in current above the limiting value. (C) 1998 El sevier Science B.V. All rights reserved.