Mechanical Properties and In Vitro Physico-chemical Reactivity of Gel-derived SiO2-Na2O-CaO-P2O5 Glass from Sand

In the present report, a bioactive glass was synthesized from silica sand as economic substitute to alkoxy silane reagents. Sodium metasilicate (Na2SiO3) obtained from the sand was hydrolyzed and gelled using appropriate reagents before sintering at 950 degrees C for 3 h to produce glass in the system SiO2-Na2O-CaO-P2O5. Compression test was conducted to investigate the mechanical strength of the glass, while immersion studies in simulated body fluid (SBF) was used to evaluate reactivity, bioactivity and degradability. Furthermore, the glass samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) to evaluate the microstructure and confirm apatite formation on the glass surface. The glass, dominated by bioactive sodium calcium silicate, Na2Ca2Si3O9 (combeite) crystals, had mechanical strength of 0.37 MPa and showed potentials for application as scaffold in bone repair.