Theory of Solvent-Mediated Long Range Force between Colloidal Particles in a Solvent: II. Interaction in an Electrolytic Solution

Abstract

The theory in the previous paper [J. Phys. Soc. Jpn. 69 (2000) 618] is extended for the interaction between two charged colloidal particles immersed in an electrolytic solution. An exact and explicit expression of the interaction is presented. The interaction is determined by solution-structures in the bulk and near the surface of colloidal particle. A similar result is also obtained for the density profile of micro-particles in the radial direction of colloidal particle. In order to compare the theory with the ones published so far, the case is discussed that the correlations between micro-ions and neutral atoms are neglected; the interaction potential consists of the van der Waals potential, the potential Φ_cc^(sol)(r) mediated by neutral atoms, and the electrostatic potential Φ_cc^(e.s.)(r). Potential Φ_cc^(sol)(r) is the one in the previous theory, while Φ_cc^(e.s.)(r) is an extention of the DLVO potential in the sense that Φ_cc^(e.s.)(r) is taken into account consistently the strong nonlinear effects through the effective charge and size of colloidal particle.