Short-time diffusion coefficients and high frequency viscosity of dilute suspensions of spherical Brownian particles

Abstract

We study the short-time collective and self-diffusion coefficients, the rotational self-diffusion coefficient, and the high frequency effective viscosity of a suspension of spherical Brownian particles. At low volume fraction these transport coefficients are given by integrals of hydrodynamic pair interactions. Using exact series expansions in powers of the inverse distance between centers of a pair of particles, we obtain accurate values for the low density transport coefficients. We consider hard spheres with mixed slip–stick boundary conditions, as well as spherical liquid droplets with an internal viscosity different from the bulk. We show that the transport coefficients depend strongly on the particle model.