Influence of heating conditions on the formation of sol- gel derived calcium hydroxyapatite

Calcium hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HA) was obtained in the sol–gel process of an aqueous solution of trans-1,2-diaminecyclohexanetetraacetic acid monohydrate (DCTA) and calcination of precursor gels at 1 000 °C. Aqueous sol-gel chemistry route based on ammonium–hydrogen phosphate as a source of phosphorus and calcium acetate monohydrate as a source of calcium ions have been developed to prepare Ca– P–O gel samples. It has been shown that adjustment of heating time and atmosphere composition can be used to control the synthesis, phase purity and morphology of ceramic samples. Phase transformations, composition and micro-structural features in polycrystalline samples were studied by thermal analysis (TG / DTA), infrared spectroscopy (IR), X-ray powder diffraction analysis (XRD) and scanning electron microscopy (SEM).