SPATIAL ORDERING AND STRUCTURE FACTOR SCALING IN THE SIMULATIONS OF COLLOID AGGREGATION

We report the observation of spatial ordering of clusters that leads to a spinodal-type scaling of the structure factor S(q), in the 3D simulations of diffusion-limited colloid aggregation. We unambiguously identify the peak in S(q) as arising from the correlation between particles belonging to nearest-neighbor clusters. The S(q) has a terminal shape that corresponds to a close packing of the clusters after gelation, in a concentration range larger than the one suggested in recent experiments. A finite-q peak in S(q) from the simulations of reaction-limited colloid aggregation is also found. © 1995 The American Physical Society.