THE DYNAMIC DOUBLE-LAYER - PART 2 - EFFECTS OF STERN-LAYER CONDUCTIONON THE HIGH-FREQUENCY ELECTROKINETIC TRANSPORT-PROPERTIES

The model developed in Part I is used to investigate the effects of St ern-layer transport on the high-frequency electrokinetic transport pro perties of spherical colloidal particles throughout the range of the z eta potential. The equations are solved numerically for Stern model (i ) (adsorption of ions onto available free surface area). The effects o f varying individual Stern-layer parameters on the magnitude and phase of the electrophoretic mobility and the real and imaginary parts of t he dipole coefficient, are discussed and compared to the case where St ern-layer conduction is absent. Regardless of the Stern-layer adsorpti on isotherm used, it is found that the presence of mobile Stern-layer ions causes the mobility magnitude to decrease and the magnitude of th e conductivity to increase, compared with the case when Stern-layer co nduction is absent. The effects of allowing the particle surface charg e density and Stern-layer charge density to vary with time are found t o be small in comparison with the overall effect of surface conduction .