Preparation of fine copper powders from organic media by reaction with hydrogen under pressure .2. The kinetics of particle nucleation, growth, and dispersion

The kinetics of very line copper powder (1 to 2 mu m) production by hydrogen reduction of solvent extracted copper chelates have been determined. The Avrami-Erafeer model for nucleation growth processes has been found to best describe the precipitation kinetics. The model parameters were correlated with reasonable success to the morphology of the copper powder. The chemically controlled particle formation process was found to exhibit 30 to 58 kJ/mol activation energy depending on the temperature range and a complex dependency (from first order to fractional/zero order) on hydrogen pressure. A steric stabilization model has been advanced to interpret the cooperative action of decanol and Versatic 10 in stabilizing the very fine copper powder dispersion.