ABSTRACT
Matijevic and Wilhelmy (1) prepared uniform spherical polycrystalline particles of cadmium sulfide (CdS) by reaction of Cd2+ ions with thioacetamide (TAA) in a dilute acidic media (pH < 2), as shown iri the TEM and SEM images of Figure 3.1.1. The reaction finished within 1 h at 26°C. They used seed crystals of CdS to promote the uniformity of the final product, and analyzed the growth kinetics using Nielsen's chronomal. The isoelectric point in terms of pH was determined to be 3.7 by electrokinetic measurement. They also prepared zinc sulfide (ZnS; polycrystalline spheres), whose isoelectric point in pH was 3.0 (2), lead sulfide (PbS; monocrystalline cubic galena) (3), cadmium zinc sulfide (CdS/ZnS; amorphous and crystalline spheres) (3), and cadmium lead sulfide (CdS/PbS; crystalline polyhedra) (3), in a similar manner.
