Preparation of ZnS/CdS composite nanoparticles by coprecipitation from reverse micelles using CO2 as antisolvent

The possibility of simultaneously recovering ZnS and US particles from reverse micelles by dissolving antisolvent CO2 into the micellar solution was investigated by high-pressure UV-Vis spectra. It was found that all the ZnS and US particles in the reverse micelles could be precipitated by compressed CO2 at suitable pressures. The phase structures and morphologies of the obtained composites were characterized by X-ray diffraction and transmission electronic micrographs. The results illustrate that the smaller molar ratio of water to surfactant of the reverse micelles and higher pressure of CO2 are favorable for producing smaller particles. This method has many potential advantages for the production of composite nanoparticles. (C) 2004 Elsevier Inc. All rights reserved.