The Effects of Different Rare Earth Dispersants on Hydroxyapatite

The effect of different dispersants such as La(NO_3)_3,Ce(NO_3)_3and Y(NO_3)_3on the dispersity of hydroxyapatite(HA) was investigated.in order to prepare uniformly dispersed particles of HA with good biological properties.Their dispersity was macroscopically characterized by means of different sedimentation rates of HA particles prepared by different dispersants in water.The microstructure of HA particles was detected using scanning electronic microscopy(SEM).Results show that the sedimentation rates of HA particles are different,when dispersant is La(NO_3)_3,the sedimentation rate of HA is the fastest and Y(NO_3)_3 the slowest.Agglomeration of HA Particles dispersed by La(NO_3)_3 is very serious,while the HA particles using dispersant Y(NO_3)_3 are more uniform and disperser.Thus,disperse effect is associated with the size and atomic weight of ions or atoms of dispersants,at the same content of different dispersants,the more stable crystals are,the smaller ionic radium and atomic weight of dispersants are,and accordingly,dispersity is better.