Preparation and Mechanism of Formation of Spherical Submicrometer Zinc Sulfide Powders

Abstract

Spherical, submicrometer particles of zinc sulfide were homogeneously precipitated by thermal decomposition of thioacetamide in acidic aqueous solutions. The rate of sulfide ion generation, determined by various combinations of temperature, PH, and initial concentrations of zinc ions and of thioacetamide, as related to particle growth rate, had the paramount effect on the particle size distribution. Monosized, bimodal, or narrow size distribution powders were obtained under certain combinations of experimental variables. Particles were porous agglomerates of ∼13‐nm sphalerite crystallites. Particle growth proceeded through diffusion‐controlled aggregation of crystallites.