Influence of Gelation Temperature on the Properties of Sol-Gel-Derived Calcium Hydroxyapatite Ceramics

An aqueous sol-gel chemistry synthesis route has been developed to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHA) samples at different gelation temperatures. In the sol-gel processes, an aqueous solution of tartaric acid as complexing agent was used. The phase transformations, composition and micro-structural properties of the polycrystalline samples were studied by thermogravimetric analysis (TG), differential thermal analysis (DTA), energy-dispersive spectrometry (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRD) and scanning electron microscopy (SEM). It was clearly demonstrated that temperature of initial stage of the preparation of CHA is a crucial parameter to obtain monophasic calcium hydroxy apatite powders with desired morphological properties.