  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.
