A light scattering study of the transition region between diffusion- and reaction-limited cluster aggregation

Two limiting regimes for colloidal particle aggregation are well described in the literature: diffusion-limited cluster aggregation and reaction-limited cluster aggregation. Between these two limiting regimes, a vast transition region is expected. In this paper, the transition region is studied by means of static and dynamic light scattering. Therefore, a system of latex particles is aggregated at different electrolyte concentrations. The time dependence of the average diffusion coefficient is fitted considering the Brownian kernel and the kernel proposed by Schmitt et al. [Phys. Rev. E 62, 8335 (2000)]. The first fits the experimental data only at high electrolyte concentrations while the latter, which considers multiple cluster-cluster contacts, is found to fit the complete set of experimental data. (C) 2001 Academic Press.