ELECTROSTATIC INTERACTION BETWEEN A CHARGE-REGULATED PARTICLE AND A SOLID-SURFACE IN ELECTROLYTE SOLUTION - EFFECT OF CATIONIC ELECTROLYTES

The effect of cations on the electrostatic interaction between a negat ive charge-regulated particle and a solid surface of constant negative potential in electrolyte solution is analyzed. Here, we assume that t he rate of approach of a particle to a solid surface is faster than th at of the dissociation of the ionogenic groups on the surface of parti cle. In other words, the effect of the time-dependent dissociation of ionogenic groups on the surface of a particle is taken into account. T he result of the present study reveals that, although the solid surfac e is negatively charged, the presence of cations in the suspension med ium has a negative effect on the rate of adhesion. The qualitative beh aviors in the variation of the interaction force between a particle an d a solid surface as a function of separation distance between them pr edicted by a kinetic model and the corresponding equilibrium model and constant charge density model are entirely different. The rate of app roach of a particle to a solid surface is on the order (constant charg e density model) > (kinetic model) > (equilibrium model).