Structural Characteristics and Thermal Properties of Bioactive Glasses Doped with Boron Oxide

Abstract

Bioactive glasses with a composition of (80 – x)NaPO₃–xB₂O₃–5CaF₂–15MgO, where x varies from 20 to 40 mol % were prepared through the melt quench technique. To examine the amorphous characteristics of the glasses and any structural modifications, X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analysis were conducted, respectively. The density of the fabricated glasses decreased as the B₂O₃ composition ranged from 20 to 40 mol %. Furthermore, the glasses were immersed in simulated body fluid (SBF) solution for 21 days for in vitro bioactivity studies. After this period, the development of apatite on the glass surfaces was assessed through XRD, FTIR, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) technique. The EDX analysis reveals an elevation in the levels of boron and calcium in the glasses that were immersed in the SBF solution for 21 days. This increase underscores the material’s bioactivity and its potential to facilitate bone regeneration and ensure long-term stability. These findings position it as a promising material for use in applications related to bone regeneration and tissue engineering. The thermal properties of the glasses were analyzed through differential scanning calorimetry (DSC), and the glass transition temperature (T_g) was determined. Interestingly, the prepared glasses revealed the presence of a boron anomaly. By systematically varying the level of B₂O₃ to NaPO₃ substitutions in the glass system, the effect of composition on several important properties is elucidated.