AGGREGATION IN CHARGE-STABILIZED COLLOIDAL SUSPENSIONS REVISITED

The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory commonly used to de scribe interactions bf charged surfaces across liquids has traditional ly been reported to fail when used for quantitative predictions of dep osition and aggregation in aqueous colloidal suspensions. Yet direct f orce measurements have recently confirmed the theory down to surface s eparations of a few nanometers. Aggregation studies on latex and hemat ite colloids now reconcile these contrasting findings, Well-known disc repancies between theory and experiment with respect to the dependence of aggregation rates on pH (or electrolyte concentration) and particl e size are shown to disappear when charge densities are reduced.