Electrokinetic phenomena in homogeneous cylindrical pores

The electrokinetic phenomena occurring in homogeneous cylindrical pores con taining symmetric electrolytes are studied. The local relations for flow in the pores (Nernst-Planck and Navier-Stokes equations) are developed. The a nalysis includes a numerical solution of the nonlinear Poisson-Boltzmann eq uation. The integral expressions of the phenomenological coefficients coupl ing the solvent flow and the electrical current with the hydrostatic pressu re and the electrical potential gradients are established and calculated nu merically. The mobilities of anions and cations are individually specified and the electroviscous effects as well as the surface conductance are taken into account. Streaming potentials obtained from numerical calculations ar e compared with results given by classical relations in a range of zeta pot entials and electrokinetic radii that may commonly occur in experimental in vestigation of micro- and ultrafiltration membranes. In this work, it is sh own that classical approximated relations can give rise to very misleading conclusions and that the determination of the true zeta potential requires a full analysis (including numerical calculations) of the basic relations f or flow and potential distribution in charged pores. (C) 1999 Academic Pres s.