Spatial correlations between charged colloidal particles: The mean spherical (dense point limit) approximation

摘要

The static structure factor of a suspension of charged polystyrene spheres is calculated within a Debyendash;Huuml;ckel level of approximation. This is based on the mean spherical closure of the Ornsteinndash;Zernike integral equation of the primitive model of the ionic solution constituted by the macroparticles and their counterions, in the limit negligible size of the latter. The explicit calculations in the dense point limit (charge of the counterions/charge of the macroparticlesrarr;0) are compared with the experimental results and it is found that this extremely simple theory reproduces the main features of the liquidlike structure of the suspension. Further quantitative refinements of the theory are naturally suggested by the method employed here, in which this Debyendash;Huuml;ckel approximation is the simplest nontrivial application.