Synthesis of hydroxyapatite by hydrothermal and microwave irradiation methods from biogenic calcium source varying pH and synthesis time

Abstract

Hydroxyapatite is the main bones and teeth inorganic mineral component. This material has been an object of research aiming its use in biomaterials as bone replacement option for biomedical applications. In this investigation, the synthesis of hydroxyapatite was studied by the Hydrothermal (HT) and Microwave Irradiation (MW) methods. Here, parameters such as pH (9 and 11) and synthesis time were varied, and residue of chicken eggshell was used as calcium precursor. The obtained powders were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Dispersive Energy X-ray Spectroscopy (EDS), and Transmission Electron Microscopy (TEM). The results showed that the material synthesized when the pH reached the value of 9 which generated less carbonated powders than those with pH of 11. The Hydrothermal method presented more satisfactory morphological results according to the TEM analysis. This procedure was considered more suitable as a route to obtain hydroxyapatite as biomaterial.