The dynamic double layer - Part 2 - Effects of Stern-layer conduction on the high-frequency electrokinetic transport properties

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