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)2·4H2O 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 500C for 2h. The results show that the mixture is composed of Ca (NO3)2, amorphous HA and ester phosphate at 200, 300 and 400℃. 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 β-Ca2P2O7 and CaO is present at 300 and 400℃. This process is simple and appropriate to produce nano-sized HA powders in large quantities.