Structural and in vitro characterization of TiO 2-CaO-P 2O 5 bioglasses

Abstract

Ternary titanium-calcium-phosphate glasses prepared by classical melting method were characterized through X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier transform infrared (FTIR) and Raman spectroscopy. The study of these glasses and the understanding of their structural characteristics are important for the clarification of their degradation behaviour especially in biological environments. XRD analysis confirmed the vitreous character of the samples, while SEM measurements indicated the presence of some heterogeneous domains on their surfaces. FTIR and Raman spectroscopy revealed a local network structure mainly based on Q 1 and Q 2 tetrahedrons connected by P–O–P linkages. A gradual depolymerization of the phosphate chains was observed with the addition of the titanium oxide. The surface reactivity of the samples containing 0.5 and 1 mol% TiO 2 has been analyzed in vitro by immersion in simulated body fluid (SBF) at 37 °C. XRD, SEM, FTIR and Raman methods were employed to characterize the structural changes occurred on the surface of TiO 2-CaO-P 2O 5 samples reacting with SBF. No apatite layer was developed on the samples surfaces but the results point out that the sample containing 0.5 mol% TiO 2 has a greater potential to develop under certain conditions an apatite phase on the surfaces.