Preparation of Ultrafine Particles of Copper by Reduction in a W/O Emulsion System.

Ultrafine particles (UFP) of Cu were prepared by reduction in a w/o emulsion system, in which Cu(II) ions dissolved in aqueous droplets were reduced by a reducing agent. This method gave a very narrow particle size distribution. Moreover, the average size of UFP could be controlled by choosing the concentration of Cu ions.