Simulation of Silica Aerogels Using Reactive Molecular Dynamics

Abstract

Reactive molecular dynamics is a powerful computational method to examine the reactive behavior of materials on an atomic level. The use of reaxFF as a potential model for the simulation of silica aerogels is investigated in this study. For the simulation of silica aerogel formation, silicic acid molecules were used as a precursor molecule and the reaction to the silica network was replicated by the increase of the simulation temperature. A condensation reaction between the silicic acid molecules was successfully observed with the use of the visualization software Ovito. The partial charges of silicon and oxygen atoms were calculated as well as the pair distribution function of siloxane bonds (Si-O) to examine the change of the molecule structures. The pair distribution function was in accordance with prior literature values. reaxFF was successfully used to simulate the formation of silica aerogels from silicic acid monomers. Further studies for optimization of parameters like the temperature and the evaporation of the free water molecules should be conducted in the future.