Rotational and translational self-diffusion of interacting spherical Brownian particles

Quasielastic light-scattering measurements are performed on a suspension of spherical particles possessing an intrinsic optical anisotropy. From the correlation function of the depolarized scattered intensity, we derive both the translational and rotational self-diffusion coefficient as functions of the volume fraction. The experimental data show that the rotational diffusion of a sphere is influenced by hydrodynamic interactions, in qualitative agreement with recent calculations by Jones.