Influence of Organic Dispersant on Morphology of Spherical Alumina Precursors

Monodispersed spherical alumina precursors were prepared by homogeneous precipitation method at very low concentration.Increasing concentration leaded to aggregation and nonspherical powders.Polyvinylpyrrolidone(PVP) and polyvinyl alcohol(PVA) were added as organic dispersants to improve the morphology.The results showed that 1% PVP can improve the state of aggregation,but with the increasing of PVP amount,the dispersing effect will be worse.PVA can improve the morphology and size distribution of the presursors.The best effect is obtained when 1% PVP and 1% PVA are used together,and the precursors are amorphous and spherical with diameter of 850 nm.