Access to Optimal Calcination Temperature for Nanoparticle Synthesis from Hydroxyapatite Bovine Femur Bone Waste

Hydroxyapatite (HAp) is one of the vital and bioactive materials that are commonly used in biomedical field and concentrated in clinical area. It is a bio-ceramic powder synthesized by using different bio-waste materials such as bovine femur bone. In this study, the bovine femur bone powder was prepared to obtain nano powder. The purpose of this study was to reach the optimal temperature to obtain nanoparticles HAp. The resulted powder was calcinated in a furnace at different temperatures (900, 950, 1000, 1050 and 1100 ℃) for 2 h at the heating rate of 10 ℃/min and cooled slowly in a furnace. Results showed, the formation of pure HAp by the presence of peaks corresponding to (PO₄)^3- at 632/cm and OH^- at 3, 572/cm in fourier transformation infrared spectroscopy (FTIR). For the calcined samples, there were three main peaks of 211, 112 and 300 planes at 2θ near 31.8, 32.2 and 32.9 respectively. The amorphous raw bones were transformed into crystalline phase and the lattice parameters for HAp c and a were calculated in X-ray diffraction (XRD), Raman analysis showed that the calcination process removed the organic compound from the bovine femur bones matrix. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) showed that the shape of the granules was irregular, containing quantities of oxygen, magnesium, sodium and carbon; the ratio of calcium to phosphate was calculated, Atomic force microscopy (AFM) showed that the particles sizes ranged from nanometers to microns. EDX result found that the calcium to phosphate ratio reached 1.7058 after calcination at 950 ℃ which was close to stoichiometric hydroxyapatite (1.67). This result implied the formation of pure HAp phase at 950 ℃.