TITLE:
Effect of SrO on the Structure of Apatite and Wollastonite Phases of Na2O-CaO-SiO2-P2O5 Glass System
AUTHORS:
Gomaa El Damrawi, Rawya Mhammed Ramadan, Mohamed El Baiomy
KEYWORDS:
Structure, Physical Properties, Gasses, Glass Ceramics
JOURNAL NAME:
New Journal of Glass and Ceramics,
Vol.11 No.2,
April
30,
2021
ABSTRACT: Glasses in the system 24.5Na2O·24.5CaO·6P2O5·xSrO·(45-x)SiO2 have been studied in the composition region of x = 0 - 15 mol%. The as prepared glassesare transparent and have an amorphous network structure. On the otherhand, heat treated glasses are transformed to opaque white glass ceramic characterized by their highly crystalline network structure. Crystalline apatite (calcium phosphate, Ca3(PO4)2, wollastonite (calcium silicate, CaSiO3), and strontium calcium phosphate Ca2Sr(PO4)2 are the main well-formed crystalline species played the major role in material bioactivity. Increasing SrO leads to enhancing material crystallite and enhances the hardness of the host glass matrix.The change of XRD spectra, 31P NMR chemical shift and hardness numberupon increasing SrO are considered due to modification of the apatitCa(PO3)2 to involve Sr ions inducing Ca2Sr (PO4)2 apatite one. Such species play the role in enhancing material properties and hardness.