Beyond diffusion-limited aggregation kinetics in microparticle suspensions

Received 3 May 2009; revised manuscript received 15 August 2009; published 2 November 2009Aggregation in nondiffusion limited colloidal particle suspensions follows a temporal power-law depen-dence that is consistent with classical diffusion limited cluster aggregation models; however, the dynamicscaling exponents observed in these systems are not adequately described by diffusion limited cluster aggre-gation models, which expect these scaling exponents to be constant over all experimental conditions. We showhere that the dynamic scaling exponents for 10 m particles increase with the particle concentration and theparticle-particle free energy of interaction. We provide a semiquantitative explanation for the scaling behaviorin terms of the long-ranged particle-particle interaction potential.DOI: 10.1103/PhysRevE.80.051402 PACS number s : 82.70.Kj, 47.65.Cb, 61.43.Hv, 87.18.Ed