FORMATION OF CDS NANOPARTICLES IN MIXED CATIONIC-ANIONIC SURFACTANT VESICLE SYSTEM

CdS nanoparticles were prepared in a mixed vesicle dispersions of the simple cationic and anionic surfactants, i.e. decyltrimethylammonium b romide and sodium 10-undecenoate, from Cd2+ or CdEDTA(2-) and H2S. UV- visible spectra were used to characterize the CdS particles formed. Th e particle size (in diameter) varied from 2.7 to > 5.0 nm, depending o n the preparation conditions. When the pH is between 9.4 and 10.0, at which the vesicles have the maximum entrapping efficiency, the smalles t particles with good stability and relative narrow dispersion are obt ained. The inner and outer surfaces are all available for the formatio n of ultrafine CdS particles. The CdS nanoparticles generated from Cd2 + are obviously smaller and much more stable than those generated from CdEDTA(2-).