Preparation Of High-grade Hydroxyapatite Powder And Dispersion

Hydroxyapatite (HAp) is a bioactive calcium phosphate ceramics. It has excellent biocompatibility, because its constitution is very similar to the inorganic part of human bone. It is widely used as bone repairing material and coating material on the substance such as titanium, titanium alloy and carbon/carbon composites.The chemical precipitation method is mostly common one among those used to prepare the HAp powders. This method is easy in practice. And the fine HAp powders synthesized by the chemical precipitation method always have high purity and low cost. However, there are also many disadvantages of this method. Firstly, the time for HAp powder preparing process is too long. Secondly, the HAp particles prepared have inhomogeneous particle sizes. Thirdly, the fluidity of the HAp powders is poor. The crystal structure was studied in this paper. On this basis, we found that the HAp aggregates mainly formed during the HAp unclearation and the drying treatment.HAp particles were synthesized by the chemical precipitation method and dispersed by the solutions of PEG 2000, (NaPO₃)₆and Lopon(?) 885 in water. The effect of different dispersants in the process on preparing HAp powder was analyzed. This paper dealt with the dispersed HAp by the means of XRD, TEM and particle size analyzer. Results indicate that the HAp particles dispersed by (NaPO₃) ₆ and Lonpon885 became smaller by the "spacial steric effect". So, the proper selection of...