CRC: Molecular-Level Structure and Dynamics at Solid-Liquid Interfaces

John T. Fourkas, Robert A. Walker, John D. Weeks（马里兰大学帕克分校）和Bruce J. Berne（哥伦比亚大学）共同支持研究固体表面液体的结构和动力学特性。该团队将结合实验和理论方法，对不同种类的液体-二氧化硅界面的行为进行准确和定量的描述。重点研究的重要问题包括：1)固液两相间力对界面结构和动力学的影响；2)液体结构和连通性对界面结构和动力学的影响；3)烷烃、烷烃腈和芳香分子之间界面行为的差异；4)表面拓扑结构对界面溶剂结构和动力学的影响。该团队将使用各种光谱工具，包括超快光学克尔效应光谱和表面选择、二阶、非线性光学光谱来研究固体界面上的液体，并将开发一种混合技术，可以探测界面上液体的取向动力学，同时排除大量液体中分子的任何信号。理论上的努力将集中于建立固体基质的现实模型，确定这些基质与相邻的液体力界面溶剂物种之间的短程相互作用如何在液体/固体界面上组织，以及这种组织如何影响动力学。一旦得到验证，这些模型将用于预测界面溶剂动力学并指导新的实验方法的发展。发展固体/液体界面结构和动力学的详细图景将对化学、物理、生物和其他科学的许多领域产生直接影响。所获得的知识将有用的领域包括腐蚀、骨钙化、润滑、分离和石油回收。该项目由化学合作研究计划（CRC）资助，为本科生、研究生和博士后提供合作培训和研究机会。

John T. Fourkas, Robert A. Walker, John D. Weeks (University of Maryland College Park) and Bruce J. Berne (Columbia University) are jointly supported to study the structural and dynamic properties of liquids at solid surfaces. The team will combine experimental and theoretical approaches to develop an accurate and quantitative description of the behavior of different classes of liquid-silica interfaces. Efforts will focus on important issues including 1) the effects of inter-phase forces between a solid and a liquid on interfacial structure and dynamics; 2) the effects of liquid structure and connectivity on interfacial structure and dynamics; 3) differences in interfacial behavior among alkanes, alkane nitriles, and aromatic molecules; and 4) the influence of surface topology on interfacial solvent structure and dynamics. The team will use a variety of spectroscopic tools, including ultrafast optical Kerr effect spectroscopy and surface-selective, second-order, nonlinear-optical spectroscopies to study liquids at solid interfaces, and will develop a hybrid of the techniques that can probe the orientational dynamics of liquids at interfaces while excluding any singnal from molecules in the bulk liquid. Theoretical efforts will focus on developing realistic models of the solid substrates, on determining how short-range interactions between these substrates and an adjacent liquid force interfacial solvent species to organize at the liquid/solid interface, and on how this organization influences dynamics. Once validated, the models will be used to predict interfacial solvent dynamics and guide the development of new experimental methods.Developing a detailed picture of structure and dynamics at solid/liquid interfaces will have a direct impact on many areas of chemistry, physics, biology, and other sciences. Examples of areas in which the knowledge gained will be useful include corrosion, bone calcification, lubrication, separations and oil recovery. This project is funded through the Collaborative Research in Chemistry Program (CRC) and provides collaborative training and research opportunities for undergraduates, graduate students, and postdoctoral fellows.