NMR spectrometer for studies of molecular transport

一个300兆赫核磁共振光谱仪与额外的设备，研究分子运输（扩散和电泳核磁共振）的设想。为此，使用了脉冲场梯度方法，这需要一个梯度脉冲控制器以及一个高功率梯度放大器和一个带有适当梯度线圈（一维，z梯度）的专用探头。应用的重点一方面是自组织软物质的输运和结构研究，另一方面是电池电解质中离子输运过程的研究。自组织材料包括胶体系统，如表面活性剂胶束，脂质体或乳液，其中分子组分的扩散系数是用1H PFG NMR测定的。这些提供了关于各自的分子定位、聚集体大小和交换过程（如果适用）的信息。特别是，重点是可开关材料的发展，其中的结构变化是由分子开关在光照射下引起的，同时在原位核磁共振监测。此外，自组织聚合物体系（嵌段或接枝共聚物，聚合物凝胶）针对各种应用领域进行了优化。PFG-NMR扩散在这里用于研究受约束几何中的分子传输过程，即在中间相和纳米通道中。在应用的第二个重点，各种Li+导电电池电解质，如离子液体，有机液体电解质，局部高浓度液体电解质或聚合物凝胶电解质，对其Li+输运性质进行了研究和优化。这包括1H， 7Li和19F的多核扩散测量，以表征所有物种的扩散率，并辅以电化学方法。特别是，电泳核磁共振用于这些系统，以确定电场中的漂移速度。借助多核表征（1H， 7Li和19F），不仅可以表征离子种类，还可以表征与它们配合的中性成分在电场中的共迁移。这可以完整地描述所有物种的迁移过程，阐明协调和簇形成的相关性，直至确定相关系数。上述应用需要足够高的磁场梯度（bbb15 T/m），以便还能够量化聚合物材料中的大聚集体和缓慢扩散。此外，电解质系统需要一个宽带扩散探头，用它可以自动依次测量芯7Li， 1H和19F。

A 300 MHz NMR spectrometer with additional equipment for studies of molecular transport (diffusion and electrophoretic NMR) is envisioned. For this purpose pulsed field gradient methods are used, which require a gradient pulse controller as well as a high power gradient amplifier and a dedicated probe head with appropriate gradient coils (one dimensional, z-gradient). The focus of the application is on transport and structural studies in self-organized soft matter on the one hand and in ion transport processes in battery electrolytes on the other hand. Self-organized materials include colloidal systems such as surfactant micelles, liposomes or emulsions in which the diffusion coefficients of the molecular components are determined using 1H PFG NMR. These provide information about the respective molecular localization, aggregate sizes and, if applicable, exchange processes. In particular, the focus is on the development of switchable materials, in which structural changes are induced by molecular switches under light irradiation and are to be monitored under in-situ NMR at the same time. Furthermore, self-organized polymer systems (block or graft copolymers, polymer gels) are optimized with regard to various fields of application. PFG-NMR Diffusion is used here to study molecular transport processes in constrained geometry, i.e. in mesophases and nanochannels. In the second focus of application, various Li+-conducting battery electrolytes such as ionic liquids, organic liquid electrolytes, locally highly concentrated liquid electrolytes or polymer gel electrolytes are examined and optimized with regard to their Li+ transport properties. This includes multinuclear diffusion measurements of 1H, 7Li and 19F to characterize all species in their diffusivity, complemented by electrochemical methods. In particular, electrophoretic NMR is used on these systems in order to determine drift velocities in the electric field. With the help of multinuclear characterization (1H, 7Li and 19F), not only ionic species, but also neutral components that coordinate to them can be characterized with regard to co-migration in the electric field. This allows a complete description of the transport process of all species, the elucidation of the relevance of coordination and cluster formation, up to the determination of correlation coefficients. Sufficiently high magnetic field gradients (> 15 T/m) are required for the above applications in order to also be able to quantify large aggregates and slow diffusion in polymer materials. Furthermore, a broadband diffusion probe head is required for the electrolyte systems, with which the cores 7Li, 1H and 19F can be measured automatically in sequence.