Monte Carlo simulation of particle aggregation and gelation: II. Pair correlation function and structure factor

M. Rottereau; J. C. Gimel; T. Nicolai; D. Durand

doi:10.1140/epje/i2004-10045-9

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2024 Impact factor 2.2

Soft Matter and Biological Physics

Eur. Phys. J. E (2004) 15: 141-148
https://doi.org/10.1140/epje/i2004-10045-9

Monte Carlo simulation of particle aggregation and gelation: II. Pair correlation function and structure factor

M. Rottereau, J. C. Gimel^*, T. Nicolai and D. Durand

Polyméres Colloïdes Interfaces, UMR CNRS, Université du Maine, F-72085, Le Mans cedex 9, France

^* e-mail: jean-christophe.gimel@univ-lemans.fr

Abstract

Diffusion-limited cluster aggregation and gelation are studied using lattice and off-lattice Monte Carlo simulations. The pair correlation function g(r) and the structure factor S(q) of the particle gels were investigated as a function of the volume fraction ( $0.5\mbox{--}49\%$ ) and time. At volume fractions below $5\%$ , the gel structure is fractal on small length scales with $d_{\rm f} = 1.8$ . g(r) shows a weak minimum at the correlation length ( $\xi$ ), before reaching the average concentration at large length scales. The cut-off function of g(r) varies during the aggregation process, but at a given $t/t_{\rm g}$ , where $t_{\rm g}$ is the gel time, it is a universal function of $r/\xi$ . At high volume fractions, the structure is dominated by excluded-volume interactions, while at low volume fractions, it is determined by the connectivity.