Modelling nanoparticle dynamics: coagulation, sintering, particle inception and surface growth

Abstract

In this paper we investigated a stochastic particle method (SPM) for solving an extension to the sintering–coagulation equation and modelled two particle systems: the production of SiO2 and TiO2. A new mass-flow stochastic algorithm to find numerical solutions to the particle model is stated. The stochastic method calculates fully the evolution of the bivariate particle size distribution (PSD) and is computationally very efficient in comparison to traditional finite element methods. The SPM was compared to a bivariate sectional method for a system with coagulation and sintering as the only mechanisms. The results obtained agree closely to those in the literature and were obtained in a small fraction of the time. An extended model with particle inception and surface growth was then used to model the TiCl4 → TiO2 system under various conditions. At low precursor concentration the effect of varying temperature was investigated, whilst at high precursor concentration the effect of surface growth on the system was explored. The results agree well with the conclusions reached previously in the literature.