Effect of Hexamethylenetetramine Concentration on the Particle Shape of Zinc Oxide Prepared by the Homogeneous Precipitation Method

The effect of (CH2)6N4 concentration on the particle shape of zinc oxide is discussed with reference to the properties of solutions. Results are as follows: formation rate of ZnO precipitate increases with increasing temperature and with increasing concentration of (CH2)6N4. At a given temperature, rapid formation of ZnO results in globes, while slow formation results in needles. However, needles are formed at a faster rate at 100°C than globes formed at 80°C. With an increase, in (CH2)6N4 concentration, the viscoisty and pH of the solution increase, while the electric conductivity decreases. In the plots of viscosity vs. (CH2)6N4 concentration, two regions with different slopes were observed, each of which corresponds to different shapes of product particles.