Synthesis of Silver Colloids: Experiment and Computational Model

We summarize our recent results that model the formation of uniform spherical silver colloids prepared by mixing iso-ascorbic acid and silver-amine complex solutions in the absence of dispersants. We found that the experimental results can be modeled effectively by the two-stage formation mechanism used previously to model the preparation of colloidal gold spheres. The equilibrium concentration of silver atoms and the surface tension of silver precursor nanocrystals are both treated as free parameters, and the experimental reaction time scale is fit by a narrow region of this two-parameter space. The kinetic parameter required to match the final particle size is found to be very close to that used previously in modeling the formation of uniform gold particles, suggesting that similar kinetics governs the aggregation process. The model also reproduces semi quantitatively the effects of temperature and solvent viscosity on particle synthesis.