SOL-GEL TRANSITION OF REVERSIBLE CLUSTER-CLUSTER AGGREGATIONS

This paper investigates the sol-gel transition of reversible cluster-c luster aggregations in terms of numerical simulations. The temperature dependence of the sol-gel transition point cb is calculated by formin g clusters with different particle concentrations for two-dimensional (d=2) and three-dimensional (d=3) systems. We present phase diagrams o n sol-gel transitions from these calculations. The fractal dimension D -f for d=3 reversible cluster-cluster aggregations is calculated at th e sol-gel transition point, which gives D/= 2.4 +/- 0.1, apparently la rger than that of diffusion-limited cluster-cluster aggregations. Thes e results show good agreement with those obtained by small-angle x-ray scattering experiments.