An effective and facile synthesis of hydroxyapatite powders using oxalic acid–ethylene glycol mixture

A method to synthesize hydroxyapatite (HAP) ceramic powders using a metal-oxalate route with calcium chloride and phosphoric acid as calcium and phosphorus precursors respectively is described. Ethylene glycol was used as a reaction medium and oxalic acid as a chelating agent. The resulting HAP powders were calcined at 600 °C for 6 h and subsequently sintered at 900 °C for 2 h. FT-IR, XRD and SEM techniques were employed for the characterization of the synthesized particles. Moreover, the influence of reaction temperature on the HAP formation was also studied. The results have shown successful formation of the crystalline, uniform sized, uniform shaped and stoichiometric HAP powders at a reaction temperature of 75 °C which was found to be the optimum temperature for the preparation. The grain size of the synthesized sample was 680 nm in length and 440 nm in width.