Cadmium sulfide aggregates through reverse micelles

CdS aggregates, composed of primary nanocrystalline particles, were synthes ized in cyclohexane-sorbitan monooleate (Span 80) reverse micelles at 800 /- 1 degreesC under mechanical agitation and sonication with varying Cd2+ c oncentrations in the solutions. The critical micelle concentration (CMC) of the surfactant Span 80 in cyclohexane was determined from discernible brea ks in the surface tension and optical (ultraviolet) absorbance versus surfa ctant concentration curves. The synthesized aggregates were characterized u sing transmission electron microscopy, X-ray diffractometry, particle-size analysis, Fourier-transform infrared spectroscopy, and thermal analyses. Th e generated aggregates exhibited the characteristic green emission at 520 n m. A minor decrease in emission intensity with increased aggregate size at the same wavelength was observed.