Short-time rotational diffusion in monodisperse charge-stabilized colloidal suspensions

We investigate the combined effects of electrostatic interactions and hydrodynamic interactions (HI) on the short-time rotational self-diffusion coefficient Dsr in charge-stabilized suspensions. We calculate Dsr as a function of volume fraction φ for various effective particle charges and various amounts of added electrolyte. The influence of HI is taken into account by a series expansion of the two-body mobility tensors. At sufficiently small φ this is an excellent approximation due to the strong electrostatic repulsion. For larger φ, we also consider the leading hydrodynamic three-body contribution.