CALCULATIONS OF ELECTRIC DOUBLE-LAYER FORCE AND INTERACTION FREE-ENERGY BETWEEN DISSIMILAR SURFACES

The nonlinear Poisson-Boltzmann theory is used to calculate the electr ical double-layer force and interaction free energy between dissimilar ly charged surfaces. For symmetric electrolytes, in addition to cases in which both surfaces maintain constant surface potential or constant surface charge during interaction, we also consider cases in which on e surface maintains constant surface potential and the other maintains constant surface charge. We further present a general algorithm for c alculating the double layer force and interaction free energy between surfaces with ionizable surface groups across electrolytes of any vale nce or composition. These results suggest interesting features of the double-layer interaction that can be observed by direct force measurem ent techniques. (C) 1995 Academic Press, Inc.