We have used small-angle depolarized dynamic light scattering in conjunction with aggregates of (rather unique) optically anisotropic spherical particles. Pure rotational diffusion is observed, and all the relevant information on a reaction-limited aggregation has been derived as a function of time. We show that the asymptotic form of the cluster mass distribution is actually attained during the very early stages of the process. The value of the exponent τ characterizing the low-mass portion of the cluster distribution is derived.

• Received 11 February 1993

DOI:https://doi.org/10.1103/PhysRevE.48.R2358