Measurement of the short-time self-diffusion coefficient in dilute and concentrated suspensions: Influence of direct particle interactions

The short-time self-diffusion coefficient of two types of monodisperse colloidal particles differing only in interparticle interactions were measured by dynamic light scattering both in dilute as well as in concentrated dispersions. The results indicate that the short-time self-diffusion is remarkably insensitive to direct particle interactions. The dependence on concentration is in good agreement with the theoretical predictions.