Preparation and properties of monodispersed spherical-colloidal particles of zinc sulphide

Abstract

Spherical-colloidal zinc sulphide particles of narrow size distribution were prepared using a two-step process. First zinc sulphide ‘seeds’ were precipitated by aging a solution consisting of zinc nitrate, nitric acid and thioacetamide. The ‘seed’ crystals were then allowed to age further at an elevated temperature. X-ray analysis showed the particles to be crystalline with structure characteristic of sphalerite. Various properties such as electrokinetic and optical, the size distribution and the specific surface area of the solids were determined and the growth mechanism was analysed in terms of Nielsen's chronomals.