Sol–gel synthesis of bioglass-ceramics using rice husk ash as a source for silica and its characterization

SiO2–Na2O–CaO based bioglass-ceramics was synthesized through sol–gel route using rice husk ash as silica source. The decomposition behavior of gel was evaluated. Sodium–calcium–silicate phases were crystallized above 700 °C. Pellet made of glass-ceramics powder was sintered at 900 °C. In vitro bioactivity and biodegradability of glass-ceramics were investigated by incubation in simulated body fluid and Tris buffer solution respectively. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to monitor the surface deposition on glass-ceramics during incubation. The material showed a good bioactivity with a formation of carbonated hydroxy apatite phase in 3 days of incubation. A quick degradation of the material was observed in Tris solution associated with an increase of pH due to the dissolution of Ca2+ and Na+ ionic species. All these results suggest the glass-ceramics, prepared utilizing rice husk ash, would be a low cost biomaterial for potential biomedical applications.