Structural Role of Strontium Oxide in Modified Silicate Glasses

Abstract In the composition range of x= 0-15 mol%, glasses in the system 24.5Na2O.24.5CaO.6P2O5.xSrO.(45-x)SiO2 have been studied. The glasses are transparent and have an amorphous network structure when they are as prepared. Heat treated glasses, on the other hand, are transformed into opaque white glass ceramics with a highly crystalline network structure. The main well-formed crystalline species in material bioactivity were apatite (calcium phosphate, Ca3(PO4)2, wollastonite (calcium silicate, CaSiO3), and strontium calcium phosphate [Ca2Sr(PO4)2. Increasing SrO improves material crystallite and increases the host glass matrix's hardness. The modification of the apatit Ca(PO3)2 to involve Sr ions inducing Ca2Sr (PO4)2 apatite one is thought to be the cause of the change in XRD spectra, 31P NMR chemical shift, and hardness number as SrO increases. These species help to improve material properties and hardness.