INFLUENCE OF HYDRODYNAMIC INTERACTIONS ON LONG-TIME DIFFUSION IN CHARGE-STABILIZED COLLOIDS

We study the influence of hydrodynamic interactions (HI) on the dynami c structure factor S(q, t) and self-diffusion of charged colloids as q uantified, respectively, by the non-exponentiality factor Delta(q) and the long-time self-diffusion coefficient D-s(L). Both quantities are calculated by constructing a novel mode-coupling scheme which accounts for HI. Our results for Delta(q) compare well with experimental data. HI are found to reduce Delta(g), and to give rise to an unexpected en hancement of D-s(L). Our results clearly demonstrate the importance of HI at volume fractions even as low as 10(-3).