Surface charges and electrokinetic charges: Distinctions and juxtapositionings

Surface charges and electrokinetic charges are very different double layer characteristics. It is mandatory to discriminate between them. If for a given system both of them are known, much relevant double layer information becomes accessible. The present state of this juxtapositioning is reviewed on the basis of real physical measurements with well-defined systems. The added information includes counterion adsorption and stagnant layer conduction. Special attention will be paid to overcharging, including an option for distinguishing between interpretation in terms of specific adsorption and ion correlations.