Preparation and physicochemical process of nanosized hydroxyapatite powders with high purity

In this paper, nano-sized hydroxyapatite powders were prepared by a sol-gel method with Ca(NO3)(2).4H(2)O and P2O5 ethanol solution as precursors. This process was simple without refluxing and the reactants were cheap compared with other sol-gel methods. The morphology and the phase structure were studied by TEM, XRD, IR, and TG-DTA. The nano-sized HA powders with high quality were prepared after the as-prepared powders were sintered at 500degreesC for 2h. The results show that the mixture is composed of Ca (NO3)(2), amorphous HA and ester phosphate at 200, 300 and 400degreesC. The amount of HA increases while the amount of Ca(NO3)(2) and ester phosphate decreases with the increase of temperature. A small amount of beta-Ca2P2O7 and CaO is present at 300 and 400degreesC. This process is simple and appropriate to produce nano-sized HA powders in large quantities.