Effect of Dispersant on the Particle Size Distribution of Cu Powders Prepared by Wet-Reduction Process

Monodispersed Cu powders were prepared in aqueous solution through a wet-reduction process with hydrazine hydrate (N2H4·H2O). In particular, the effect of the dispersant such as sodium pyrophosphate decahydrate (Na4O7P2·10H2O), carboxymethyl cellulose sodium salt (CMC) in water solvent on the particle size for the prepared Cu powders was investigated. The Cu powders essentially were monodispersed and irregular in shape regardless of reaction temperature and dispersant. In the case of adding the Na4O7P2·10H2O, the particle size of Cu powders increased with the increase of reaction temperature, which the particles were agglomerated in irregular shape and became to be large. The particle size distributions was asymmetry and to be broad regardless of reaction temperature. On the other hand, when the CMC was added, the particle size of Cu powders, which were much finer compared with adding the Na4O7P2·10H2O as a dispersant, was not much changed with reaction temperature. The particle size distribution of Cu powder was much narrow regardless of reaction temperature. As a result, it would be suggested that the CMC was more effective dispersant reagent to produce the monodispersed and fine Cu powders with narrow size distribution using the wet chemical reduction process