Application of NMR spectroscopy for the investigation of structure-mobility relations in nanoporous host-guest systems in concerted action with IR Micro-Imaging

核磁共振波谱与红外显微成像协同作用研究纳米多孔主客体系统的结构-迁移关系

基本信息

批准号：
277602929
负责人：
Professor Dr. Jürgen Haase
金额：
--
依托单位：
Abteilung Grenzflächenphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/277602929?language=en
关键词：
Application NMR spectroscopy investigation structure

项目摘要

With the focus on instrument-based and methodical work, in the course of the project KA 953/20-1,2, the background was set for new micro-imaging methods (measurement of transient concentration profiles with IR and interference microscopy). They provide a new approach to the exploration of molecular dynamics in nanoporous host-guest systems. NMR diffusometry with pulsed field gradients (PFG NMR) constitutes another microscopic method, which is complementary in a double fashion. First, it is applied under equilibrium conditions and, second, in the variation of temperature and pressure (and thereby of the guest loading) a much wider range can be covered (moreover, the variation is achieved with much less experimental effort). The potential offered by the concerted application of PFG NMR and Micro-Imaging shall be purposefully employed in this project to deepen our knowledge on molecular dynamics in nanoporous materials. The proposal is submitted in parallel with the application of C. Chmelik on "Micro-Imaging for the exploration of diffusion and reaction in nanoporous materials". A successful approach of the posed questions will be achieved only by the concerted use of both techniques. Besides technical and instrument-based developments for the use of PFG NMR in the particular fields (including the variation of temperature, pressure and observation time above the current limits), the work will be centered on the following three topics: (i) The combined measurement of self-diffusion (PFG NMR, this project) and transport diffusion (Micro-Imaging) establishes unprecedented options for the investigation of the interrelation of transport phenomena under equilibrium and non-equilibrium conditions. This is one of the fundamental questions of current research in the investigation of mesoscopic molecular systems under spatial confinement, which shall be in the focus of the studies within the first topic. (ii) We are, second, going to examine and to exploit the options of PFG NMR to study the impact of host-guest interactions on host structure and guest dynamics. This includes, in particular, the option of temperature variation over a wide range, in which drastic changes in the characteristics are expected. For the understanding of these processes and, possibly, even for their mere detection, a particular wide variation is essential. (iii) While the host-guest interactions considered in the second topic was found to give rise to a completely new type of hysteresis phenomena sorption hysteresis in mesoporous materials is known since over 100 years. However, the origin of this phenomenon and the intrinsic mechanisms determining its time dependence are still a topic of controversial discussion. With the information obtained by the combined application of PFG NMR and Micro-Imaging on the intrinsic dynamics of such systems we hope to contribute, within a third topic of our research plan, with so far inaccessible experimental evidence.

在 KA 953/20-1,2 项目过程中，重点关注基于仪器和有条不紊的工作，为新的微成像方法（使用红外和干涉显微镜测量瞬态浓度分布）奠定了背景。它们为探索纳米多孔主客体系统中的分子动力学提供了一种新方法。脉冲场梯度核磁共振扩散测定法 (PFG NMR) 构成了另一种微观方法，它以双重方式互补。首先，它是在平衡条件下应用的，其次，在温度和压力（以及客体负载）的变化中，可以覆盖更广泛的范围（此外，通过更少的实验工作来实现变化）。本项目应有目的地利用 PFG NMR 和显微成像的协同应用所提供的潜力，以加深我们对纳米多孔材料分子动力学的了解。该提案与 C. Chmelik 的申请“用于探索纳米多孔材料扩散和反应的显微成像”同时提交。只有协同使用这两种技术才能成功解决所提出的问题。除了在特定领域（包括超出当前限制的温度、压力和观察时间的变化）使用 PFG NMR 的基于技术和仪器的开发外，工作将集中在以下三个主题：（i）自扩散（PFG NMR，本项目）和输运扩散（显微成像）的测量为研究平衡和非平衡条件下输运现象的相互关系提供了前所未有的选择。这是当前空间约束下介观分子系统研究的基本问题之一，也是第一个主题的研究重点。 (ii) 其次，我们将检查并利用 PFG NMR 的选项来研究主客体相互作用对主体结构和客体动力学的影响。这尤其包括大范围温度变化的选择，其中预计特性会发生剧烈变化。为了理解这些过程，甚至可能只是为了检测它们，特别广泛的变化是必要的。 (iii) 虽然第二个主题中考虑的主客体相互作用被发现会引起一种全新类型的滞后现象，但介孔材料中的吸附滞后现象已为人所知已有 100 多年的历史。然而，这种现象的起源以及决定其时间依赖性的内在机制仍然是一个有争议的讨论话题。通过结合应用 PFG NMR 和显微成像获得的有关此类系统内在动力学的信息，我们希望在我们研究计划的第三个主题中提供迄今为止无法获得的实验证据。