The effect of calcium suspension concentration on the hydroxyapatite structures and purity

Abstract

The presented work aimed to the hydroxyapatite (HAP) preparation through the wet precipitation method, which consists of drop-wise phosphoric acid addition to stirring calcium suspension. For this, the materials called CPW10, CPW50, CPW100 and CPW200 were obtained by using the concentration of the calcium suspension as variable. To characterize the obtained materials, XRD, FTIR, SEM/EDS and TGA analysis were carried out. The results obtained showed that the calcium suspension concentration plays a crucial role for the structure and purity of the prepared materials. It found that low reagent dispersion i.e. high concentration leads to the formation of carbonated hydroxyapatite with secondary phases including the un-reacted calcium source. Moreover, low suspension concentrations promote the formation of the carbonated hydroxyapatite as a single-phase. Indeed, the results demonstrate that the increase in the calcium concentration is accompanied by an increase of the carbonate contents in the final materials.