NMR spectrometer for studies of molecular transport

设想了一台300 MHz的核磁共振谱仪，以及用于研究分子传输(扩散和电泳核磁共振)的附加设备。为此，使用了脉冲场梯度法，它需要一个梯度脉冲控制器、一个高功率梯度放大器和一个带有适当的梯度线圈(一维、z-梯度)的专用探头。应用的重点是一方面研究自组织软物质的传输和结构，另一方面研究电池电解液中的离子传输过程。自组织材料包括胶体体系，如表面活性剂胶束、脂质体或乳剂，其中分子组分的扩散系数使用1H PFG核磁共振来确定。这些信息提供了有关各自的分子定位、聚集大小和交换过程(如果适用)的信息。特别是，重点是可开关材料的开发，在这种材料中，分子开关在光照射下诱导结构变化，并在原位核磁共振下进行监测。此外，自组织聚合物系统(嵌段或接枝共聚物、聚合物凝胶)针对不同的应用领域进行了优化。PFG-核磁共振扩散用于研究分子在受限几何结构中的传输过程，即在介相和纳米通道中的传输过程。在第二个应用重点中，考察和优化了各种锂离子导电电池电解液，如离子液体、有机液体电解液、局部高浓度液体电解液或聚合物凝胶电解液的锂离子传输性能。这包括1H、7Li和19F的多核扩散测量，以表征所有物种的扩散性，并辅之以电化学方法。特别是，在这些系统上使用了电泳核磁共振，以确定电场中的漂移速度。借助于多核表征(1H、7Li和19F)，不仅可以表征离子物种，而且可以表征与它们配位的中性组分在电场中的共迁移。这使得能够完整地描述所有物种的运输过程，阐明配位和集群形成的相关性，直到确定相关系数。上述应用需要足够高的磁场梯度(&gt；15T/m)，以便也能够量化大聚集体和聚合物材料中的缓慢扩散。此外，电解液系统还需要一个宽带扩散探头，用它可以按顺序自动测量岩芯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.