Effective role of CaO/P'2O'5 ratio on SiO'2-CaO-P'2O'5 glass system

摘要

In the present work, the effect of the CaO/P"2O"5 ratio on the composition of sol-gel synthesized 58SiO"2-(19-x)P"2O"5-(23+x)CaO (x=0, 5, 10 and 15mol%) glass samples was studied. Further, the effect of NBO/BO ratio on hydroxy carbonated apatite layer (HCA) forming ability based on dissolution behavior in simulated body fluid (SBF) solution was also investigated. CaO/P"2O"5 ratios of synthesized glass samples were 1.2, 2, 3.6, and 9.5, respectively. NBO/BO ratios were obtained using Raman spectroscopic analysis as 0.58, 1.20, 1.46, and 1.78, respectively. All samples were soaked in the SBF solution for 7days. The calculated weight losses of these samples were 58%, 64%, 83%, and 89% for corresponding NBO/BO ratios. The increase in CaO/P"2O"5 ratio increases the NBO/BO ratios. However, the increase in NBO/BO ratio increases HCA forming ability of SBF treated samples. The HCA crystalline layer formation was confirmed through X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Raman and Infrared spectroscopic analysis. Higher CaO/P"2O"5 ratio favors the increase in HCA formation for SBF treated calcium phospho silicate glasses.