A model for simultaneous homogeneous and heterogeneous nucleation in the case of slow reaction rate

Our previous model for simultaneous homogeneous and heterogeneous nucleation, which was successfully tested for silver particle generation by a chemical reduction method, is extended to the case of slow reaction rate. Nucleation in a system containing seed particles in the case where the reaction rate is slow occurs according to the following rule: homogeneous nucleation is predominant when n(P)/n(0)* (n(P) is the seed number concentration, and n(0)* the number concentration of homogeneously nucleated particles without seed particles), and heterogeneous nucleation is predominant when n(P)/n(0)* < 1. This theoretical prediction is in good agreement with the experimental results obtained for zinc sulfide particles generated by homogeneous precipitation. (C) 2000 Academic Press.