Effect of MgO on bioactivity, hardness, structural and optical properties of SiO2–K2O–CaO–MgO glasses

Glass composition 55SiO2–10K2O–(35−x)CaO–xMgO is synthesized by a melt quench technique. The as quenched and simulated body fluid (SBF) soaked glasses are investigated for their bioactive, optical and structural properties. These properties are discussed in the light of the role of MgO. The hardness increases with content of MgO instead of CaO. No remarkable change in the XRD pattern has been observed in unsoaked and soaked glasses in SBF for 28 days. The pH values initially increases rapidly and later stage of soaking it changes slowly. The soaked glasses exhibit some new FTIR bands as compared to virgin glasses. The optical band gap of the soaked samples is higher and Urbach energy lower with respect to pristine glass powder. The ion released into the SBF solution and consequent pH rise are maximum for glass sample containing minimum amount of Mg. The higher MgO containing glasses show low dissolution rate of Mg2+, K+ and Ca2+ cations. Among all the glasses G2 show highest bioactivity.