SYNTHESES OF COPPER NANOPARTICLES IN GELIFIED MICROEMULSION AND IN REVERSE MICELLES

Syntheses of nanosized copper crystallites have been carried out in re verse micelles and in gelified microemulsion. The self assemblies have been prepared by using a mixture of sodium and copper di(2-ethylhexyl ) sulphosuccinate as surfactants. In reverse micelles, at low water co ntent (w=[H2O]/[AOT]<6), pure metallic copper particles are observed w hereas at relatively high water content (w>6) the oxidation of metalli c particles cannot be prevented. At w=10, pure copper oxide nanopartic les are observed. In gelified microemulsion (w=70), metallic nanoparti cles are obtained. Their stability with time is rather long. Oxidation occurs after several days. This indicates a drastic change in the mec hanism and rate of particle growth in the gelled systems as compared w ith those in reverse micelles. (C) 1997 Elsevier Science B.V.