Understanding Vibrational Energy Transfer and Spectra in Microporous and Mesoporous Materials

堪萨斯大学的Ward H.Thompson得到了理论和计算化学计划的支持，并得到了刺激竞争研究的实验计划的部分支持，该计划对微孔和介孔硅酸盐溶胶中的振动能量转移和光谱进行了理论研究。在这项工作中，以溶胶凝胶孔为重点，模拟了能量传递过程和振动光谱，开发了研究分子水平机理的方法，并探索了孔尺寸、表面化学以及溶剂和溶质性质的影响。本研究采用量子经典分子动力学模拟、标准微扰理论模拟和经典非平衡分子动力学模拟相结合的方法，对溶胶凝胶孔中纯液体和溶胶孔中双原子和三原子溶质的振动能量传递和光谱进行了模拟。此外，正在开发研究振动能量转移的机制和光谱以及有效地估计能量转移速率常数的方法。这项工作将加深对纳米结构多孔凝胶中能量传递以及红外和拉曼测量的理解，同时精确地计算振动光谱和能量传递速率常数，可以与实验结果相比较。它还将产生详细的机理信息，这些信息将显著提高对能量传递途径的理解，并有助于解释微孔和介孔材料的振动光谱。在更广泛的影响方面，拟议工作的结果将有助于微孔和介孔材料的设计和表征，因为它提高了对能量流动和光谱探针这两条路径的理解。在各种各样的纳米结构系统中，这些都是重要的问题。因此，这项研究将与微孔和介孔催化剂、超分子组装、模板材料、反胶束、生物系统、水凝胶、膜、燃料电池电极和非线性光学材料等材料中的光谱、能量传递、热流和反应性相关。这项工作还应该提供对分子电子、光学和机械设备中的能量耗散的洞察。

Ward H. Thompson of the University of Kansas is supported by the Theoretical and Computational Chemistry program and partially supported by the Experimental Program To Stimulate Competitive Research to conduct a theoretical investigation of vibrational energy transfer and spectra in microporous and mesoporous silicate sol-gels. In this work focusing on sol-gel pores, energy transfer processes and vibrational spectra are being simulated, methods for investigating the molecular-level mechanisms are being developed, and the effect of pore size, surface chemistry, and solvent and solute properties are being explored. In this study mixed quantum-classical molecular dynamics simulations, standard perturbation theory approaches, and classical nonequilibrium molecular dynamics simulations are being used to simulate vibrational energy transfer and spectra of neat liquids in sol-gel pores and diatomic and triatomic solutes in solvents confined in sol-gel pores. In addition, approaches for investigating the mechanisms of vibrational energy transfer and spectra and efficiently estimating energy transfer rate constants are being developed. This work will improve the understanding of energy transfer and infrared and Raman measurements in nanostructured porous sol-gels while at the same time accurately computing vibrational spectra and energy transfer rate constants that can be compared with experimental results. It will also yield detailed mechanistic information that will significantly improve the understanding of energy transfer pathways and assist in the interpretation of vibrational spectra in microporous and mesoporous materials. In terms of broader impacts, the results of the proposed work will assist in the design and characterization of microporous and mesoporous materials by improving the understanding of both pathways for energy flow and spectroscopic probes. These are important issues in a wide, and growing, variety of nanostructured systems. Thus, this study will be relevant to spectroscopy, energy transfer, heat flow, and reactivity in materials such as microporous and mesoporous catalysts, supramolecular assemblies, templated materials, reverse micelles, biological systems, hydrogels, membranes, fuel cell electrodes, and nonlinear optical materials. This work should also provide insight into energy dissipation in molecular electronic, optical, and mechanical devices.