Aggregation reaction-limited, computer

Computer simulations of a similar growth process, called reaction-limited cluster-cluster aggregation, have been performed (IS). This simulation... 

Figure 8. Transmission electron micrographs of typical clusters of gold, silica, and polystyrene colloids, prepared by both diffusion-limited and reaction-limited cluster aggregation and by computer simulation. There is a striking similarity in the structure of the clusters of different colloids in each regime.

The solubility of silica is also important. Figure 48.7 shows the relative dissolution rate for aqueous silicates as a function of pH [23]. The rate is slow at low pH so there is little bond redistribution. SAXS studies coupled with computer simulations have shown that under these conditions reaction-limited cluster-cluster aggregation is... 

Computer simulations have shown that the value of fractal dimension largely depends on whether the aggregation process is controlled by the diffusion rate of the clusters and single particles or by their chemical reactivity at the time of collision, the latter being mainly controlled by the DLVO forces. This observation, in agreement with experimental work on aerosols and colloids, has led to a new classification of aggregation processes the reaction-limited and diffusion-limited cluster aggregation (RLCA and DLCA respectively) processes. 

In the literature, several functional forms for S(qR ) can be found [51,52]. The difficulty lies in obtaining an expression for the structure factor that is valid for the whole range qR > 1. Lin et al. [53] calculated the aggregate structure factor directly from computer-generated clusters obtained under diffusion and reaction-limited conditions. They parameterized their result by fitting the polynomial expression ... 

Gonzalez, A.E. 1993. Universality of colloid aggregation in the reaction limit— the computer-simulations. Physical Review Letters 71 (14) 2248-2251. 

The basic theoretical approach for the analysis of diffusion controlled reactions is due to Smoluchowski [9] who developed it for the analysis of diffusion limited aggregation of colloidal particles. We discuss the generalization of this approach to the case of rodlike molecules here. The computational method best suited for the simulation of the polymerization of rodlike molecules is Brownian dynamics. We discuss in this review both multiparticle Brownian dynamics and pairwise Brownian dynamics the latter is a hybrid method combining Smoluchowski s [9] theory and Brownian... 

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