Diffusion in concentrated monodisperse colloidal solutions. The hard sphere—thermodynamic or hydrodynamic?

Abstract

An empirical two-particle mobility tensor can be obtained by fitting the calculated mutual and local self-diffusion constants to available experimental data for hard-sphere-like dispersions. This mobility tensor, along with DLVO theory for the interparticle potentials, is used to calculate the mutual, local and long-time self-diffusion constants of a range of charge-stabilized dispersions at volume fractions up to the disorder–order transitions. In particular, we contrast these dynamic properties for dispersions which are dilute in a hydrodynamic sense, but thermodynamically non-ideal, with those that are genuinely concentrated.