Enhancement of Bioactivity, Mechanical and Degradation Properties of the Diopside by Incorporation of Ba2+ Ion via Sol–gel Combustion Route

Abstract

Over the last decade, bioactive silicates have gained significant interest as bone graft substitutes due to their excellent ability to repair, replace, and regenerate damaged tissue in injured bone. In this work, a sol–gel combustion route was used to synthesize nanostructured barium-doped diopside (Ca_1-XBa_XMgSi₂O₆) using stoichiometric amounts of calcium nitrate, magnesium nitrate, and barium nitrate as oxidizers, and tartaric acid as a fuel. The resultant powder was examined by powder XRD to confirm the phase purity. Pure phase of diopside was achieved at 850 °C without any secondary phase. For functional group analysis, FT-IR was employed, and microscopic imaging (SEM/EDAX) was used to study morphological changes. Due to barium doping in the diopside matrix, the crystallite size was reduced, and the mechanical and degradation properties of the prepared pellets was enhanced after immersion in SBF medium over a period of time. The results show compressive strength of the doped diopside was found to be 169 MPa, closer to cortical bone strength and similar to previous findings. It can be concluded that barium can be considered as a dopant to improve bioactivity of Ca-Mg silicate for hard tissue application.