Hydrothermal Synthesis And Characterization Of Ion Substituted Hydroxyapatite

Hydroxyapatite (Ca₁₀（PO₄）₆（OH）₂, HA) has excellent biocompatibility andbioactivity. It has wide application in biomedical field. The synthetic HA doped withcertain ions is more resemble with biological apatite and is expected to be better hardtissue replace material. In this study, HA nano-powders doped with Mg, Zn and Sr ionswere successfully synthesized by EDTA assisted hydrothermal method. Thesynthesized products were comprehensively characterized by X-ray diffraction （XRD）,X-ray fluorescence spectrometry （XRF）, transmission electron microscopy （TEM）, andthermogravimetric analysis （TGA）.The main results are as follows:①All the samples have the structure of HA androd-like morphology. The length of the pure HA was from40nm to200nm, and thewidth was form10nm to30nm. The lengths of the Mg doped HA, Zn doped HA and Srdoped HA particles were from10nm to70nm, from20nm to200nm and from10nm to70nm, respectively.②Doping of Mg, Zn did not significantly change the aspectratio of HA particles. But the aspect ratio of the Sr doped HA particles was decreased.③Lattice parameters a, c decreased with the increase of Mg doping. The latticeparameter a decreased and then increased with Zn doping. Lattice parameter cdecreased with the increase of Zn doping. The lattice parameter a increased with theincrease of Sr doping and the lattice parameter c increased first and then decreasedwith the increase of Sr doping.④The molar ratio of （Ca+Mg）/P was decreased withthe increase of Mg doping. The molar ratio of （Ca+Zn）/P did not have obvious changewith Zn doping. The molar ratio of （Ca+Sr）/P increased with the increase of Sr doping.⑤Mg doping increased physical absorption water, and had little effect on thermalstability of HA. Zn doping increased physical absorption water and decreased crystalwater, and then increased thermal stability. Sr doping increased crystal water, and thendecreased thermal stability.