Titania effect on the bioactivity of silicate bioactive glasses

Abstract

This study reports about the influence of titania on the structure and bioactivity of 60SiO2 ⋅ (32 − x)CaO · 8P2O5 · xTiO2 glasses with 0 ≤ x ≤ 12 mol%. In order to analyse the evolution of the apatite structure self‐assembled on the glass surface after immersion in simulated body fluid, a complementary approach of different techniques was applied such as X‐ray diffraction, Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy and Raman spectroscopy. It was evidenced that the crystalline hydroxyapatite amount and the size of the nanostructured apatite phase, i.e. crystalline and amorphous one, decrease with the rise of TiO2 content. FT‐IR spectra recorded in reflection mode showed the increase of the apatite‐like structure amount as the titania content became higher. On the other hand, the behaviour of the full width at half maximum of the most intense Raman signal originating from the apatite‐like structure confirms the size decrease of the nanostructured apatite phase with the progressive addition of TiO2 and shows the existence of a less ordered apatite‐like structure. The herein presented investigation demonstrates that the FWHM of the Raman signal combined with the FT‐IR data recorded in reflection mode can be used as key spectral indicators for elucidating the evolution of apatite‐like structures developed on the bioactive material surface. Copyright © 2016 John Wiley & Sons, Ltd.