Oxygenated Apatites: Effect of Calcium Salt Nature and Synthesis Parameters

Apatitic calcium phosphates, reported in this study, are prepared following a precipitation reaction between phosphoric acid (H3PO4) and a calcium salt. Used salts are calcium carbonate (CaCO3), calcium nitrate (Ca(NO3)2) and calcium chloride (CaCl2). The variation in the chemical composition and crystallinity of oxygenated apatites, carbonated or not, depending on the nature of the reagents and the synthesis parameters was studied by X-ray diffraction, infrared spectroscopy and by chemical analysis. The insertion of molecular oxygen into the apatite tunnel is achieved through the use of hydrogen peroxide (H2O2). The content of molecular oxygen in the apatite is then determined by volumetric analysis. Graphical abstract: Calcium salt + H3PO4 Cax(PO4)y(HPO4)z(OH)u(O2 2- )v(O)w