Influence of the partial substitution of CaO with MgO on the thermal properties and in vitro reactivity of the bioactive glass S53P4
Influence of the partial substitution of CaO with MgO on the thermal properties and in vitro reactivity of the bioactive glass S53P4
复制标题
DOI：
10.1016/j.jnoncrysol.2012.06.032
复制
发表时间：
2012-09-15
影响因子：
3.5
通讯作者：
Hupa, M.
中科院分区：
文献类型：
--
作者：
Massera, J.;Hupa, L.;Hupa, M.
研究了高达 4 mol% 的 MgO 替代 CaO 对生物活性玻璃 S53P4 性能的影响。利用热分析、热台显微镜和 X 射线衍射法来测量玻璃的热性能和结晶特性。通过将眼镜在模拟体液中浸泡 4 小时至 1 周来测量体外生物活性。通过玻璃表面的 FTIR 光谱分析和 SEM 图像评估富含二氧化硅和羟基磷灰石层的形成。增加 MgO 对 CaO 的替代量可降低玻璃化转变、熔化起始和终止以及熔化温度。玻璃化转变和结晶的活化能也分别从 (790 +/- 30) 下降到 (407 +/- 30) kJ/mol 和从 (283 +/- 30) 下降到 (145 +/- 30) kJ/mol，表明以 CaO 为代价，渐进式 MgO 的键长减小，键合强度增加。在浸泡的前 24 小时内，所有玻璃在 SBF 中的溶解情况相同，随后在颗粒表面形成羟基磷灰石。随着MgO含量的增加，表面层的厚度减小。对于较长的浸泡时间，具有最高 MgO 含量的玻璃与模拟体液相比，表现出比不含 MgO 的玻璃更慢的反应趋势。玻璃结构和体外性能的这些变化可能对具有大表面积与体积比的生物活性玻璃产品感兴趣。 (C) 2012 Elsevier B.V. 保留所有权利。
The influence of up to 4 mol% substitution of MgO for CaO on the properties of the bioactive glass S53P4 was studied. Thermal analysis, hot stage microscopy and X-ray diffractometry were utilized to measure the thermal properties and the crystallization characteristics of the glasses. The in-vitro bioactivity was measured by immersing the glasses for 4 h to one week in simulated body fluid. The formation of silica rich and hydroxyapatite layers was assessed from FTIR spectra analysis and SEM images of the glasses surface. Increasing substitution of MgO for CaO decreased the glass transition, the onset and endset of melting and the fusion temperatures. The activation energies for glass transition and crystallization also decreased from (790 +/- 30) to (407 +/- 30) kJ/mol and from (283 +/- 30) to (145 +/- 30) kJ/mol, respectively, indicating a decrease in bond length and an increase in bond strength with progressive MgO at the expense of CaO. All glasses dissolved identically in SBF during the first 24 h of immersion with subsequent formation of hydroxyapatite at the grain surfaces. The thickness of the surface layers decreased with increasing MgO content. For longer duration of immersion, the glasses with the highest MgO contents exhibited a slower reaction tendency, with simulated body fluid, than the Mg-free glass. These changes in the glass structure and in-vitro properties may be of interest for products from bioactive glasses with large surface area to volume ratio. (C) 2012 Elsevier B.V. All rights reserved.