Effect of thermally induced structural disorder on the chemical durability of International Simple Glass
Effect of thermally induced structural disorder on the chemical durability of International Simple Glass
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DOI：
10.1038/s41529-018-0052-3
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发表时间：
2018-09-11
影响因子：
5.1
通讯作者：
Li, Hong
中科院分区：
文献类型：
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作者：
Angeli, Frederic;Charpentier, Thibault;Li, Hong
虽然硅酸盐玻璃的组成对其化学耐久性的影响越来越为人所知，但结构的作用还不是很清楚，但对于准确描述水相蚀变机理是至关重要的。可以通过改变玻璃的热历史来研究结构无序的影响。此外，核玻璃中自辐射引起的结构变化可以与快猝灭引起的结构变化进行比较。在深层地质处置玻璃基质的背景下，解决结构对玻璃耐久性的影响是具有挑战性的。在这里，一种名为国际简易玻璃的硼硅酸盐玻璃被玻璃化，以获得快速淬火的样品。利用原位拉曼光谱和布里渊光谱对其猝灭速率和虚化温度进行了估算。多核核磁共振被用来洞察淬火对原始和变化的玻璃结构的影响。在快冷玻璃中观察到较高的键角分布和较低的碱混合。一些AlO4基团被钙补偿，而BO4的一部分转化为BO_3单元。结构修饰使90℃正向速率下发生的硅酸盐网络的水解率增加了1.4-1.8倍，具体取决于pH值。残留率制度也同样受到影响，在二氧化硅饱和溶液中进行的实验开始时，影响更明显。这些发现证明，在不同的蚀变制度下，玻璃的反应性仍然受其结构控制。
While the influence of silicate oxide glass composition on its chemical durability is increasingly known, the contribution of structure only is less well understood, yet is crucial for an accurate description of aqueous alteration mechanisms. The effect of structural disorder can be investigated by varying the thermal history of the glass. Furthermore, the structural changes generated by selfirradiation in nuclear glasses can be compared with those induced by fast quenching. In the context of deep geological disposal of vitreous matrices, it is then challenging to address the structural impact on glass durability. Here, a borosilicate glass, the International Simple Glass, was fiberized to obtain a rapidly quenched sample. The quenching rate and fictive temperature were evaluated from in situ Raman and Brillouin spectroscopies. Multinuclear nuclear magnetic resonance was used to obtain insight into the effect of quenching on the pristine and altered glass structure. Higher bond angle distribution and lower mixing of alkalis were observed in the fast quenched glass. Some of AlO4 groups are then Ca-compensated, while a part of BO4 is transformed into BO3 units. The structural modifications increase the hydrolysis of the silicate network occurring in the forward rate regime at 90 degrees C by a factor of 1.4-1.8 depending on the pH value. Residual rate regime is similarly affected, more significantly at the beginning of the experiments conducted in silica saturated solutions. These findings prove that the reactivity of glass remains controlled by its structure under the various alteration regimes.