Cadmium Sulfide Aggregates through Reverse Micelles

CdS aggregates, composed of primary nanocrystalline particles, were synthesized in cyclohexane-sorbitan monooleate (Span 80) reverse micelles at 80°± 1°C under mechanical agitation and sonication with varying Cd²⁺ concentrations in the solutions. The critical micelle concentration (CMC) of the surfactant Span 80 in cyclohexane was determined from discernible breaks in the surface tension and optical (ultraviolet) absorbance versus surfactant concentration curves. The synthesized aggregates were characterized using transmission electron microscopy, X-ray diffractometry, particle-size analysis, Fourier-transform infrared spectroscopy, and thermal analyses. The generated aggregates exhibited the characteristic green emission at 520 nm. A minor decrease in emission intensity with increased aggregate size at the same wavelength was observed.