Preparation of Thermally Stable Nanohydroxyapatite by Microwave Process

Nanosized hydroxyapatite powders were prepared by a microwave process using Ca(NO3)2·4H2O and(NH4)2HPO4 as starting materials. The powder is composed of rod-shaped particle that is about 30nm in width and 80-200nm in length. The synthesized powders were measured by X-ray diffraction, transmission electron, infrared spectroscopy and thermogravimet-ric analysis. Various parameters such as time and power of microwave irradiation have significant effects on thermal stability of hydroxyapatite. The results show that the decomposition temperatures of HAP increase with time prolonging and power increasing of microwave irradiation. When the time and power of microwave irradiation are1h and 700W, and the sample treated at 500℃ for 3h, HAP is still stable at 1200℃.