Kinetics of nanoparticle nucleation, growth, coalescence and aggregation: A theoretical study of (Ag)n nanoparticle formation based on population balance modulated by ligand binding

Understanding the mechanism of nanocluster formation during their synthesis is important in determining the different variables that govern their formation, size distributions, and stability. Here, we use the method of moments to solve the rate equations for the kinetics of metal cluster formation starting from a well-mixed solution of metal ions and reducing agents. With the incorporation of coalescence, we detected a drastic change in size distribution with a small change of a parameter - the initial ion concentration or the coalescence rate coefficient. This is a manifestation of a threshold beyond which the number of possible combinations for aggregation of clusters increases abruptly during coalescence. We observe the sensitivity of nanocluster size distribution to the coalescent growth rate and the effect of a strong ligand stabilizer in impeding coalescence.

Automated summary

Understanding the mechanism of nanocluster formation is crucial for determining their properties. In this study, we used the method of moments to solve the rate equations and found that the size distribution of nanoclusters drastically changes with small variations in initial ion concentration or coalescence rate. The number of possible cluster combinations increases abruptly during coalescence. We also observed the sensitivity of nanocluster size distribution to coalescent growth rate and the inhibiting effect of a strong ligand stabilizer.