Synthesis of Silica/Hydroxyapatite Nanocomposite by Mechanochemical Method

Abstract Biocompatibility of Silica makes it a suitable material for biomedical applications. The main components of teeth and bones are calcium phosphate (CP). Hydroxyapatite (HA) is expected to be used in different fields not only in biomedical applications but also in agriculture as a fertilizer and pollution treatment. Various substitutions in the apatite lattice play a significant role in its properties. In the present work, Silica-50, 40, 30 and 25 mol.% Hydroxyapatite nanocomposites were prepared successfully by mechanochemical processing method. X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) indicated that silica stimulates the HA decomposition to β-tricalcium phosphate (β-TCP). XRD of heat-treated compacted sample at 1200oC confirmed β-TCP and calcium phosphate silicate phases formation. Mechanical properties decreased with decreasing HA content. Electrochemical impedance spectroscopy (EIS) results revealed that pure HA possess the highest resistivity to corrosion, while the silica/HA samples showed lower corrosion resistance. The polarization resistance increases with HA content.