Structural, optical and bioactive properties of calcium borosilicate glasses

摘要

Glass of composition 40SiO_2-20B_2O_3-30CaO-10M_2O_3(M = Al, Cr, Y and La) were prepared by the splat quenching technique to investigate the effect of M_2O_3 on their bioactivity, structural and optical properties. Y_2O_3 and Cr_2O_3 containing glasses formed a crystalline hydroxyapatite (HA) layer after dipping in simulating body fluid (SBF) for 25 days. On the other hand, HA layer could not form in Al_2O_3 and La_2O_3 glasses. However, during soaking in SBF solution, these glasses exhibit higher dissolution rate, lower density and increased optical band gap as compared to unsoaked glasses. Their oxygen molar volume was also higher than for Y_2O_3 and Cr_2O_3 glasses. The change in composition affects the cross-link formation in the glass matrix and finally its durability and bioactivity in SBF. The results show that M_2O_3 plays an important role in controlling chemical durability and bioactivity of the glasses.