Synthesis and Characterization of Sol-Gel Derived SiO<sub>2</sub>-CaO Glass

Abstract

A phosphate-free glass based on SiO2-CaO was synthesized by a low temperature acid catalysed sol-gel route. The obtained material was evaluated by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The XRD analysis showed the sol-gel derived glass was amorphous in nature and crystallized when sintered at temperature above 900oC. The crystalline state was consisted of quartz and wollastonite phases. Meanwhile the infrared analysis showed typical transmission bands of monolith silica in the binary glass pattern. The bioactivity of the amorphous glass was investigated in vitro in simulated body fluid (SBF). The amorphous glasses were soaked in SBF for 1, 3 and 7 days. It is notable that the obtained results from FTIR, SEM and EDS analyses showed the deposition of spherical-shaped crystalline hydroxyl-carbonate-apatite (HCA) on the surface of the glass within 3 days of immersion in SBF solution. The HCA deposition was covered most of the surface after 7 days of immersion.