XRD, SEM-EDS, and FTIR studies ofin vitro growth of an apatite-like layer on sol-gel glasses

Abstract

A glass with a composition (in mole %) of: SiO₂ (70), CaO (26), and P₂O₅ (4) was obtained using a sol-gel method. The in vitro bioactivity of the glass was assessed by determining the changes in surface morphology and composition after soaking in simulated body fluid (SBF) for periods of up to 14 days at 37°C. X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, and FTIR analyses of the glass surface after different soaking periods in SBF demonstrated the growth of an apatite-like layer on the glass surface. In the first stage, an amorphous calcium phosphate layer was formed; after 7 days this surface consisted of spheres, with diameters ranging between 2 and 15 μm, composed of needle-like apatite crystallites (250 × 100 nm) with a crystallinity similar to that of a biological apatite. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 44, 416–421, 1999.