SUBMICROMETER ZINC-OXIDE PARTICLES - ELABORATION IN POLYOL MEDIUM ANDMORPHOLOGICAL-CHARACTERISTICS

A novel and easy route for preparing submicrometer particles of zinc o xide, involving hydrolysis of zinc salt in a polyol medium, is propose d. Zinc acetate dihydrate and diethyleneglycol appear to be the best c andidates for obtaining a high yield of particles with well-defined mo rphological characteristics. Monodisperse spherical particles in the s ubmicrometer range (0.2 - 0.4 mum) have been obtained for a salt conce ntration less than 0.1 mol 1(-1). The particle size depends mainly on the heating rate. The particles are microporous (surface area: 80 m2 g -1) and are formed by aggregation of small crystallites (10 nm). Calci nation at moderate temperature drastically reduces this porosity witho ut significant interparticle sintering. At higher concentration, no ag gregation occurs and tiny single crystallite particles are obtained.