Scaling of the Structure Factor in Fractal Aggregation of Colloids: Computer Simulations

dc.creatorGonzalez, Agustin E.
dc.creatorRamirez-Santiago, Guillermo
dc.date1996-05-14
dc.date.accessioned2026-07-07T03:08:33Z
dc.date.available2026-07-07T03:08:33Z
dc.descriptionIn the volume fraction range (0.005,0.08), we have obtained the temporal evolution of the structure factor $S(q)$, in extensive numerical simulations of both diffusion-limited and reaction-limited colloid aggregation in three dimensions. We report the observation of scaling of this structure function in the diffusion-limited case, analogous to a spinodal decomposition type of scaling. By comparing $S(q)$ with the pair correlation function between particles, we were able to identify the peak in the structure factor as arising from the correlations between particles belonging to nearest-neighbor clusters. The exponents $a\prime$ and $a\prime \prime$ that relate the position and the height of the maximum in $S(q)$ vs. time, respectively, were also obtained and shown to differ somewhat from the spinodal decomposition exponents. We also found a terminal shape for $S(q)$ that corresponds to a close packing of the clusters after gelation. Moreover, this picture was shown to be valid in a concentration range larger than the one suggested in recent experiments. Although the $S(q)$ for reaction-limited colloid aggregation does not show a pronounced peak for the earlier times, eventually the peak stretches and becomes higher than in the diffusion-limited case. The $S(q)$ curves, however, do not present the scaling shown for diffusion-limited aggregation.
dc.descriptionRevtex 29 pages, Figs available upon request, To be published in Journal of Colloids and Interface Science
dc.identifierhttps://arxiv.org/abs/cond-mat/9605086
dc.identifierhttp://arxiv.org/abs/cond-mat/9605086
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/27541
dc.subjectCondensed Matter
dc.titleScaling of the Structure Factor in Fractal Aggregation of Colloids: Computer Simulations
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