Simple approximate expressions for electrical double-layer interaction at constant moderate potentials

Simple yet accurate expressions for the electrical double-layer interaction force and energy between the particles that hold for a wide range of surfa ce potential is required in the modeling, simulation, and optimization of m any processes employed in industry. In this paper, simple approximate expre ssions for the interaction are obtained based on the asymptotic results and the numerical solution to the Poisson-Boltzmann equation for identical par allel plates with constant surface potential up to 180/z(i) mV at 25 degree s C, and the Dejaguin approximation. Within the moderate surface potential range, the semianalytical expressions agree well with the exact numerical r esults and are convenient to use for the purpose of process modeling and si mulation. (C) 2000 Academic Press.