Nuclear magnetic resonance spectroscopy of disordered solids

由于无序，玻璃的分子级结构本身就很难研究。核磁共振光谱学特别适合于研究无序固体，因为它主要对给定原子核的局部环境敏感。我们将使用核磁共振来研究核废料玻璃。开发耐用到足以容纳数千年放射性废离子的玻璃，需要详细和可靠地了解这些离子是如何结合在玻璃中的。核磁共振将提供有关废离子在玻璃网络中的位置以及它们是否分解为不太耐久的相的结构信息。高温核磁共振还将告知玻璃在固化过程中从熔体中分离出不同的相，以及如何通过添加其他元素来防止这种情况。这项工作的结果将是优化核废料玻璃耐久性的成分和工艺，并确保放射性废料产品安全地保存在地质储存库中。核磁共振还将用于研究离子导电玻璃，这种玻璃对更小、更便携和高容量电池的使用很有兴趣。高温核磁共振将被用来表征离子在玻璃网络中的运动，并定义扩散通道的分子结构。这将使高性能材料的设计具有增强的离子传导性，同时保持化学耐久性。最后，我们将继续探索核磁共振可检测性的前沿领域，这些系统曾经被认为是“不可能的”，但现在正通过新的方法和仪器变得可用。在这一领域的成功将扩大核磁共振的用途，用于目前超出其能力范围的广泛材料的结构阐明。

The molecular-level structure of glasses is inherently difficult to study because of disorder. Nuclear magnetic resonance (NMR) spectroscopy is uniquely suited for studying disordered solids because it is principally sensitive to the local environment about a given nucleus. We will use NMR to study nuclear waste glasses. The development of glasses durable enough to contain radioactive waste ions for millennia requires a detailed and reliable understanding of how these ions are bonded in the glass. NMR will provide structural information about where the waste ions are located in the glassy network, and whether they separate into less-durable phases. High-temperature NMR will also inform about the separation of different phases during glass solidification from the melt, and how to prevent this by the addition of other elements. The result of this work will be compositions and processes that optimize the durability of nuclear waste glasses and ensure that the radioactive waste products remain safely contained in geologic repositories. NMR will also be used to study ion-conducting glasses which are of interest for use in smaller, more portable and high-capacity batteries. High-temperature NMR will be used to characterize the movement of ions through a glassy network, and to define the molecular structure of the diffusion channels. This will enable the design of high-performance materials with enhanced ionic conductivity while maintaining chemical durability. Finally, we will continue to explore the frontiers of NMR detectability in systems once considered "impossible", but now are becoming accessible with new methodology and instrumentation. Success in this area will expand the utility of NMR for structural elucidation of a vast range of materials currently beyond its capability.