Engineering Model for Homogeneous Nucleation

Abstract

In addition to the classical thermodynamical theories on nucleation, a relationship between number concentration of particles generated by homogeneous nucleation and operating conditions are theoretically and experimentally studied. A model, where the number concentration of particles generated by homogeneous nucleation n^* is determined so that the generation rate of monomers (as precursors) G^* is equal to their vanishing rate at monomer concentration C^*, which corresponds to a critical supersaturated state of nucleation, is proposed. The cell model, which is often used in particle-dispersed systems is applied and the solution of unsteady diffusion rate of monomers onto a nucleus is used in the analysis. As a result, we obtain the relation among the parameters as G^*=4πr^*DC^*n^*, where D is diffusion coefficient of monomer, and r^* is radius of nucleus. The experimental results obtained for silver particles generation by a reduction method are found to qualitatively support the present model.