Structure of fluoride-containing bioactive glasses
Structure of fluoride-containing bioactive glasses
复制标题
DOI：
10.1039/b900956f
复制
发表时间：
2009-01-01
影响因子：
--
通讯作者：
Hill, Robert G.
中科院分区：
文献类型：
--
作者：
Brauer, Delia S.;Karpukhina, Natalia;Hill, Robert G.
氟化物可防止蛀牙、刺激骨矿化并降低玻璃的熔化温度，因此是用作牙科或整形外科生物材料的生物活性玻璃的有趣组分。然而，在设计新的玻璃组合物时，需要更好地理解玻璃中氟化物的结构作用。我们的特点是玻璃系列的系统SiO2-P2 O 5-CaO-Na 2 O与CaF 2的浓度增加。通过添加CaF 2将网络连接性固定在2.13，而所有其他组分的比率保持恒定。F-19和Si-29 MAS NMR谱表明，添加CaF 2不会通过形成Si-F键而导致玻璃网络的破坏，而是形成混合的钙氟化钠物质。P-31 MAS NMR显示磷酸根以正磷酸根形式存在。因此，它不形成实际玻璃网络骨架的一部分，并且不存在Si-O-P键。Na-23 MAS NMR表明存在多个钠位点，随着CaF 2含量的增加，钠的平均配位数增加。玻璃化转变温度随CaF 2含量的增加而降低。由于没有形成Si-F键，这可以通过假设的CaF+物质的形成来解释。研究结果可用于设计新的含氟生物活性玻璃组合物的特定应用。
Fluoride prevents dental cavities, stimulates bone mineralisation and decreases the melting temperature of glasses and is therefore an interesting component of bioactive glasses for use as dental or orthopaedic biomaterials. However, when designing new glass compositions, the structural role of fluoride in the glass needs to be better understood. We have characterised a glass series in the system SiO2-P2O5-CaO-Na2O with increasing concentrations of CaF2. Network connectivity was fixed at 2.13 by adding CaF2 while the ratio of all other components was kept constant. F-19 and Si-29 MAS NMR spectra showed that addition of CaF2 does not cause disruption of the glass network by formation of Si-F bonds but forms mixed calcium sodium fluoride species. P-31 MAS NMR showed phosphate being present as orthophosphate. Hence it does not form part of the actual glass network backbone and no Si-O-P bonds are present. Na-23 MAS NMR showed the presence of multiple sodium sites with an increase in the mean coordination number of sodium with increasing CaF2 content. The glass transition temperature decreased with increasing amounts of CaF2. As no Si-F bonds were formed, this can be explained by formation of hypothetical CaF+ species. The results can be used for designing new fluoride-containing bioactive glass compositions for specific applications.