Fractal dimensions of silica gels generated using reactive molecular dynamics simulations

Sudin Bhattacharya; John Kieffer

doi:10.1063/1.1857522

Fractal dimensions of silica gels generated using reactive molecular dynamics simulations

J Chem Phys. 2005 Mar 1;122(9):094715. doi: 10.1063/1.1857522.

Authors

Sudin Bhattacharya¹, John Kieffer

Affiliation

¹ Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2158, USA.

PMID: 15836170
DOI: 10.1063/1.1857522

Abstract

We have used molecular dynamics simulations based on a three-body potential with charge transfer to generate nanoporous silica aerogels. Care was taken to reproduce the sol-gel condensation reaction that forms the gel backbone as realistically as possible and to thereby produce credible gel structures. The self-similarity of aerogel structures was investigated by evaluating their fractal dimension from geometric correlations. For comparison, we have also generated porous silica glasses by rupturing dense silica and computed their fractal dimension. The fractal dimension of the porous silica structures was found to be process dependent. Finally, we have determined that the effect of supercritical drying on the fractal nature of condensed silica gels is not appreciable.