CONCENTRATED DISPERSIONS OF CHARGED COLLOIDAL PARTICLES - SEDIMENTATION, ULTRAFILTRATION AND DIFFUSION

The formation and structure of sedimentation and/or filtration layers built up by charged colloidal particles were studied. For that purpose a theoretical model based on the force balance on a given particle in the layer was developed. The colloid stability problem and appearance of coagulation were considered. The hydrodynamic permeability of a filtration layer, consisting of charged particles, was calculated for different values of the electrolyte concentration, filtration rate, particle surface potential and radius. A simple expression for estimation of the collective diffusion coefficient of charged colloidal particles at relatively high volume fractions was also proposed.