Concepedia

Abstract

The formation and growth of gas-made silica particles by co-agulation and sintering is investigated theoretically. A model for the characteristic time for silica sintering is proposed defining a minimum primary particle diameter above which macroscopic expressions are applied. The value of the minimum primary particle diameter is selected consistently with molecular dynamics simulations. The proposed characteristic sintering time is tested using a monodisperse model for aggregate dynamics by coagulation and sintering. The model predictions are compared with experimental data for silica formation and growth in premixed flames and hot wall aerosol flow reactors by oxidation of hexamethyl-disiloxane (HMDSO) and silicon-tetrachloride (SiCl4).