Experimental and Theoretical Studies of Microscopic Dynamics in Liquids

波士顿学院的John Fourkas教授受实验物理化学项目资助，对散装和受限液体的动力学和结构进行实验和理论研究。虽然几十年的超快激光研究已经揭示了大量的体积液体结构和溶剂化现象，但纳米孔结构中更复杂的液体问题是该领域的一个新领域。典型的是由100个或更少的分子组成的液体池。本提案旨在对溶胶-凝胶玻璃中的液体进行测量，具体目标是确定分子形状如何影响液体动力学，极端限制如何影响液体的行为以及限制如何影响相变温度。PI随后提出对液体进行理论研究，利用瞬时正态理论将液体分子间势的非调和效应加入到相关函数的计算中。这项建议的一个成功成果将是能够预测与地球化学和生物化学有关的现象的新的密闭液体模型。溶剂化具有极其重要的工业应用，对这一现象更完整的理论认识可能会产生重要影响。密闭空间中液体的实际例子包括多孔岩石中的碳氢化合物和由生物分子构成的水。在解决多孔岩石中水流和溶解物质的问题方面，这项工作也具有环境意义。

Professor John Fourkas of Boston College is funded by the Experimental Physical Chemistry program to conduct experimental and theoretical studies on the dynamics and structure of bulk and confined liquids. While decades of ultrafast laser studies have revealed much about bulk liquid structure and solvation phenomena, the more complex problem of liquids in nanoporous structures is a new horizon in this field. Pools of liquids consisting of 100 molecules or less are typical. This proposal seeks to make measurements on liquids in sol-gel glasses, with the specific goals of determining how molecular shape influences liquid dynamics, how extreme confinement affects the behavior of liquids and how confinement affects phase-transition temperatures. The PI then proposes to conduct theoretical studies on liquids, adding the effects of anharmonicity of the intermolecular potential of a liquid into the computation of correlation functions using instantaneous normal mode theory. A successful outcome of this proposal would be new models of confined liquids that could predict phenomena relevant to geochemistry and biochemistry. Solvation has extremely important industrial applications, and a more complete theoretical understanding of this phenomenon could have an important impact. Practical examples of liquids in confined spaces include hydrocarbons in porous rocks, and water structured by biological molecules. There are also environmental implications of this work, in addressing the issue of flow of water and dissolved species in porous rock.