A theory of self-diffusion in concentrated dispersions is presented, in which the effects of hydrodynamic and direct interactions between macroparticles are virtually decoupled. The long-time self-diffusion coefficient $D_s^L$ is written in terms of the radial distribution function of the suspended particles and of their short-time self-diffusion coefficient $D_s^S$. The predictions for the volume fraction dependence of $D_s^L$ in hard-sphere suspensions are in excellent agreement with available experimental results.

• Received 16 November 1987

DOI:https://doi.org/10.1103/PhysRevLett.60.2705