Synthesis and Characterization of Nano-hydroxyapatite Powder Using Wet Chemical Precipitation Reaction

Hydroxyapatite(HA) nano-powder was synthesized via wet chemical technique in a used precipitation reaction,in which Ca(OH)2and H3PO4were used as precursors.Deionised water was used as a diluting media for the reaction and ammonia was used to adjust the pH.The synthetic HA nano-powder has some medical applications such as a coating material in orthopaedic implants and in dental.HA powder has been studied at different temperatures from 100 to 800 ℃ to achieve the stoichiometric Ca/P ratio 1.667.The optimum temperature was found to be 600 ℃.Above this temperature,the HA powder decomposed to CaO.The crystallite size of HA powder was found to be in the range of 8.47—24.47 nm.The crystallographic properties were evaluated by X-ray diffraction,Fourier transform infrared spectroscopy,energy dispersive Xray spectroscopy and scanning electron microscopy.The results show that,high purity of nano-hydroxyapatite powders could be obtained at low temperatures,and the crystallinity,crystallite size and Ca/P ratio of the resulting nanoparticles were found to be dependent on the calcination temperature.When Ca/P ratio exceeded1.75,formation of CaO phase was observed.