Implementation of a discrete nodal model to probe the effect of size-dependent surface tension on nanoparticle formation and growth

Abstract

This article presents a study of the effect of size-dependent surface tension, on the formation and evolution of nanoparticles during gas-to-particle conversion. The nuclei formation rates have been computed from chemical reaction like formulation as opposed to the most commonly used expression from kinetic homogeneous nucleation theory derived on the basis of steady-state assumption and capillarity approximation (size-independent constant surface tension). This is achieved with discrete nodal model. We validate the present model by comparing the solution for Aluminum particle growth with our earlier NGDE model [Prakash, A., Bapat, A. P., & Zachariah, M.R. (2003). A simple numerical algorithm and software for solution of nucleation, surface growth, and coagulation problems. Aerosol Science and Technology, 37, 892–898], a system that shows a size-dependent surface tension. The results indicate that although the quasi-steady-state assumption of the dynamics is reasonable, the capillarity approximation significantly over-predicts the size of the particles.