Nuclear magnetic resonance spectroscopy of disordered solids

由于无序，玻璃的分子水平结构本质上很难研究。核磁共振（NMR）光谱学是唯一适合研究无序固体，因为它主要是敏感的局部环境对一个给定的核。我们将用核磁共振来研究核废料玻璃。要开发出能够容纳放射性废离子的玻璃，需要对这些离子在玻璃中的结合方式有详细而可靠的了解。NMR将提供关于废离子在玻璃状网络中的位置以及它们是否分离成不太耐用的相的结构信息。高温核磁共振还将告知在玻璃凝固过程中不同相从熔体中分离的情况，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组合物和工艺，并确保放射性废物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，这些玻璃可用于更小，更便携和高容量的电池。高温核磁共振将用于表征离子通过玻璃状网络的运动，并确定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，我们将继续探索曾经被认为是“不可能”的系统中的NMR可检测性的前沿，但现在正在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效用，目前超出其能力的大量材料的结构说明。

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.