Kinetic theory of a concentrated suspension of axisymmetric solute particles

Abstract

A new generalized diffusion equation is derived for a suspension of interacting axisymmetric brownian particles subjected to a time-dependent external field. Explicit molecular expressions are obtained for the generalized Onsager mobility tensors. Because of the external field, additional ‘field’ mobilities appear in the theory. These can be related but not totally reduced to the Onsager mobility tensors. For translationally invariant systems a separate equation is obtained for the orientational distribution of brownian particles. This equation is a generalization of the familiar Debye equation applicable to interacting axisymmetric particles. The generalized rotational diffusion equation is found to be non-local with respect to the orientational variable. A simple quasihydrodynamical model is used to obtain estimates of the mobility tensors.