Transition from semiorder to disorder in the aggregation of dense colloidal solutions

By using low-angle static light scattering we study the aggregation of dense colloidal solutions under diffusion limited (DLCA) and reaction limited cluster aggregation (RLCA) conditions. While it has been recently shown that DLCA surprisingly leads to a semiordered state, we show here that any order is lost under RLCA conditions. While in the first case a scattering peak at finite wave vector q is observed, in the second the scattered peak always occurs at q=0.