Ultrafine Cu particles prepared by mechanochemical process

The solid-state displacement reaction of CuCl2 + 2Na = Cu + 2NaCl induced by mechanical milling has been studied. Ultrafine Cu particles have been produced after removing the by-product NaCl from the as-milled mixture in a washing process. Two different morphologies of Cu particles were observed by transmission electron microscopic examinations. Cu particles of uniform size in the range of 20-50 nm were found after a steady-state reaction during mechanical milling, whereas larger particles were observed when combustion had occurred.