Brownian-dynamics simulation of concentrated charge-stabilized dispersions. Self-diffusion

Abstract

The Brownian-dynamics algorithm is used to simulate charge-stabilized dispersions at volume fractions up to 0.55. Interparticle potentials are described by the usual double-layer repulsion plus van der Waals attraction and the velocity-dependent hydrodynamic interactions are expressed by an effective, volume-fraction-dependent, two-particle mobility tensor. The particle mean-square displacement and the local self- and tracer-diffusion constants are calculated from the time-ordered configurations generated by the simulation. This is done for dispersion volume fractions up to and beyond the disorder–order phase transition.