Electrical double layer interactions under regulation by surface ionization equilibria–dissimilar amphoteric surfaces

Abstract

The electrostatic interaction between similar and dissimilar double layers under regulated approach is considered. During the interaction the surface potentials and charges are regulated by the association and dissociation of ionizable groups at each surface. A new method, similar to the method of isodynamic curves, is developed to study this problem. This method can provide a qualitative description of the salient features of the surface charge, the surface potential and the pressure between the surfaces as a function of separation without first having to obtain an exact solution of the problem. This qualitative and the accompanying exact solution are presented in terms of the Gouy–Chapman approximation as an illustration of the role of surface regulation during interaction.