Influence of hydrodynamic interactions on long-time diffusion in charge-stabilized colloids

Abstract

We study the influence of hydrodynamic interactions (HI) on thedynamic structure factor S(q,t) and self-diffusion of chargedcolloids as quantified, respectively, by the non-exponentiality factorΔ(q) and the long-time self-diffusion coefficient DsL. Both quantities are calculated by constructing a novelmode-coupling scheme which accounts for HI. Our results forΔ(q) compare well with experimental data. HI are foundto reduce Δ(q), and to give rise to an unexpectedenhancement of DsL. Our results clearly demonstratethe importance of HI at volume fractions even as low as 10−3.