LIGHT-SCATTERING-STUDIES OF AGGREGATION PHENOMENA

We present recent results in the field of colloidal aggregation. We fi rst present static light scattering data of aggregation in intermediat e regimes between RLCA and DLCA. In particular, we show that working w ith dense solutions, new and unexpected features are observed. In fact , we measure intensity distributions strongly peaked at q not equal 0, which scale according to the same scaling law typical of spinodal dec omposition. Furthermore, we show that by only varying the initial cond itions, the appearance of the peak can be completely inhibited, and th at this result provides new information about the intermediate regimes . Finally, we present depolarized dynamic light scattering data from a ggregates grown in the RLCA regime. We show that using optically aniso tropic spheres it is possible to determine in a unique experiment all the features characterizing an aggregation process. Moreover, we prese nt evidence that the asymptotic form expected for the cluster mass dis tribution is attained in the very early phases of the aggregation proc ess.