ENGINEERING MODEL FOR HOMOGENEOUS NUCLEAT ION

In addition to the classical thermodynamical theories on nucleation, a relationship between number concentration of particles generated by h omogeneous nucleation and operating conditions are theoretically and e xperimentally studied. A model, where the number concentration of part icles generated by homogeneous nucleation n is determined so that the generation rate of monomers (as precursors) G is equal to their vani shing rate at monomer concentration C, which corresponds to a critica l supersaturated state of nucleation, is proposed. The cell model, whi ch is often used in particle-dispersed systems is applied and the solu tion 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=4 pi r*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.