Received: February 29, 2000

In Final Form: June 30, 2000

Abstract:

Nanostructured semiconductor particles are currently under intense investigation because of their interesting photophysical and photochemical properties. Several preparation methods have been exploited for this class of materials; among them, the use of reverse micelles or "water-in-oil" microemulsions is a simple and successful preparative route. In this paper, a novel synthetic medium has been exploited, consisting of a quaternary CTAB/n-pentanol/n-hexane/water microemulsion. The presence of cosurfactant (n-pentanol), in addition to water, allows the simultaneous modulation of the water droplets dimensions and their exchange dynamics. Nanoparticles were characterized by UV-vis and photoluminescence spectroscopy, High-Resolution Transmission Electron Microscopy, and Raman spectroscopy. All measurements showed that the mean size of the nanoparticles is governed by the pentanol content of the system. They also possess a narrow size distribution and a good degree of crystallinity. Moreover, pentanol has an influence on the stability of CdS clusters, behaving as a capping agent at high concentrations. Stopped-flow measurements elucidated the influence of the cosurfactant in the kinetics of nucleation and growth.

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