Synthesis and characterization of mesoporous bioactive glasses with highly ordered structures and high surface areas by a self-assembly process

Abstract

Mesoporous bioactive glasses (MBGs) are considered to be outstanding bone-repairing materials. MBGs were prepared by a two-step acid-catalyzed self-assembly (TSACSA) process combined with a hydrothermal reaction. To synthesize the optimized texture organization, an orthogonal experiment was designed under the same conditions (acid concentration, calcination temperature, hydrothermal time and hydrothermal temperature). The MBGs were characterized by N2 adsorption analysis, SAXS and TEM. The in vitro bioactivity was investigated by XRD and FTIR after soaking in SBF for 3 and 6 h. The results illustrated that the calcination temperature was the key factor affecting pore volume and the specific surface area. The hydrothermal temperature had the greatest impact on pore size. Compared with MBG prior to hydrothermal treatment, MBG after hydrothermal treatment displays more highly ordered mesopores and more uniform cylindrical pores. In the in vitro bioactivity test, synthesized MBG presents hydroxyapatite (HA) mineralization activity within a short time. The optimal conditions of the synthetic process were 1 mol L−1 hydrochloride acid, a hydrothermal reaction temperature of 120 °C for 24 h and a calcination temperature of 500 °C. This resulted in a large pore volume (1.22 ± 0.06 cm3 g−1) and high specific surface (679 ± 32 m2 g−1).