title: Kinetics and morphology of cluster growth in a model of short-range attractive colloids.
abstract: We present results from detailed three-dimensional Brownian dynamics simulations of the self-assembly process in quenched short-range attractive colloids. Clusters obtained in the simulations range from dense faceted crystals to fractal aggregates which show ramified morphology on large length scales but close-packed crystalline morphology on short length scales. For low volume fractions of the colloids, the morphology and crystal structure of a nucleating cluster are studied at various times after the quench. As the volume fraction of the colloids is increased, growth of clusters is controlled by cluster diffusion and cluster-cluster interactions. For shallower quenches and low volume fractions, clusters are compact and the growth-law exponent agrees well with Binder-Stauffer predictions and with recent experimental results. As the volume fraction is increased, clusters do not completely coalesce when they meet each other and the kinetics crosses over to diffusion-limited cluster-cluster aggregation (DLCA) limit. For deeper quenches, clusters are fractals even at low volume fractions and the growth kinetics asymptotically reaches the irreversible DLCA case.
authors.affiliation: Department of Physics, Kansas State University, Manhattan, Kansas 66503, USA.
authors.forename: Siddique J
authors.initials: SJ
authors.lastname: Khan
authors.forename: C M
authors.initials: CM
authors.lastname: Sorensen
authors.forename: A
authors.initials: A
authors.lastname: Chakrabarti