稀土分散剂对羟基磷灰石的影响

采用稀土La（NO3）3,Ce（NO3）3和Y（NO3）3做分散剂,化学沉淀法制备了颗粒分散均匀的羟基磷灰石（HA）粉体,以实现其良好的力学和生物性能.宏观上观察了HA颗粒在水中的沉降速度、沉降高度研究不同分散剂的分散效果,微观上通过扫描电子显微镜（SEM）和透射电镜（TEM）观察其颗粒的微观形貌,比较各自的分散性.并测量了块体HA的显微硬度、压缩强度进一步验证分散效果.结果表明：用Y（NO3）3分散的HA颗粒沉降速度最慢,颗粒分布均匀,分散效果最好,随着分子量的增大,分散效果愈差,Ce（NO3）3其次,La（NO3）3最差.力学性能与羟基磷灰石颗粒的分散效果密切相关,采用Y（NO3）3时HA的显微硬度和压缩强度最高分别为87.55和92.44MPa,Ce（NO3）3,La（NO3）3作分散剂时依次减弱.研究表明,采用稀土分散剂能制备分散性良好的HA粉体,提高HA的力学和生物性能.

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.