RETRACTED ARTICLE: Investigation of the structural properties and bioactivity of P2O5–CaO–Na2O–TiO2 glass and glass-ceramics synthesized via a novel sol–gel method by acetone and DMF solvents

Abstract

Because of the significant effect of the sol–gel method on the glass morphology at the relatively low processing temperature, in the present work, phosphate glass and glass-ceramic nanopowders with the general formula of (P2O5)55–CaO)25–(Na2O)20−x–(TiO2)x, (x = 5, 10, and 15 mol%) have been synthesized via a facile sol–gel method. For this purpose, acetone and dimethylformamide (DMF) have been used as a polar and non-protic solvent. The proportion of triethylphosphate to acetone or DMF has been selected 1:3 that they have been synthesized at 25 °C and pH = 5–6. The glass powders have been dried at 315 °C. Then, the powders synthesized by acetone have been calcined at 500 and 750 °C, and the powders synthesized by DMF have been calcined at 550, 650, and 750 °C. The glass and glass-ceramic nanopowders have been analyzed by several techniques, X-ray powder diffraction (XRD), Differential thermal analysis (STA), Fourier transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller and Barrett–Joyner–Halenda (BET–BJH), and Scanning electron microscopy (SEM-EDS). The XRD results have been confirmed the amorphous nature of all glass samples, while after calcination, the samples have been shown the peaks assigned to β-TCP and hydroxyapatite. The SEM images have shown that the synthesized glass and glass-ceramic powders by both acetone and DMF solvents have a particle size below 50 nm and spherical morphology. Also, the glass and glass-ceramic powders, after soaking in the simulated body fluid (SBF) for 7 days, depicted the formation of hydroxyapatite and carbonated-hydroxyapatite layer on the surface of the glass and glass-ceramic powders, respectively.