X-Ray Studies of Liquids Near Interfaces and in Thin Films

本研究的重点是对液体中界面秩序的研究。连续流体力学在解释和预测散装液体的行为方面非常成功，但在界面附近，液体是由原子或分子组成的这一事实不容忽视。许多实验表明，固液界面附近的液体的性质往往与散装液体的性质不同。该项目的前期研究表明，使用同步加速器x射线直接观察界面液体结构是可能的。在目前的项目中，正常（非液晶、非粘弹性、非金属）分子液体将被研究。观察到的界面有序与衬底表面结构和剪切速率的关系将被详细研究。从这些研究中获得的知识将有助于确定液体在界面上表现不同的方式和原因，从而最终帮助设计特定的界面液体特性。由于界面液体出现在许多日常过程中，这种研究可能最终导致技术进步。该项目将通过在跨学科环境中培训研究生，并为他们提供使用尖端同步加速器设备的经验，将研究和教学结合起来。培训将为他们在学术界、工业界和政府的一系列职业生涯做好准备。本研究主要是对液体中界面序的研究。许多实验表明，界面附近液体的性质往往与散装液体的性质不同；这意味着液体分子的排列在界面附近发生了变化。这个小组最近的工作表明，使用同步加速器x射线直接观察这些重排是可能的。在当前的项目中，将研究界面附近分子液体中的有序，并详细研究观察到的有序与衬底表面结构和剪切速率的关系。从这些研究中获得的知识将帮助我们更好地理解液体在界面上的行为如何以及为什么不同，从而最终帮助设计特定的界面液体特性。由于界面液体在许多熟悉的过程中起着至关重要的作用，如润滑、粘附、过滤、采油、润湿/扩散/涂层等，这些研究最终可能会从这些过程的改进中为社会带来好处。该项目将把研究和教学结合起来，在跨学科的环境中培养研究生，并让他们体验使用先进的国家同步加速器设施，如先进光子源和国家同步加速器光源。这种培训将为他们在学术界、工业界和政府的一系列职业生涯做好准备。

This research is focused on the investigation of interfacial order in liquids. Continuum hydrodynamics has been extremely successful at explaining and predicting the behavior of bulk liquids, but the fact that liquids are made up of atoms or molecules cannot be ignored in the vicinity of an interface. Many experiments have shown that the properties of liquids near solid-liquid interfaces are often different from those of the bulk liquid. Prior research with this project has shown that it is possible to use synchrotron X-rays to directly observe the interfacial liquid structure. In the current project, normal (non-liquid-crystalline, nonviscoelastic, nonmetallic) molecular liquids will be studied. The dependence of the observed interfacial ordering on substrate surface structure and shear rates will be investigated in detail. The knowledge gained from such studies will help determine how and why liquids behave differently at interfaces, and thus ultimately help design specific interfacial liquid properties. Since interfacial liquids appear in many everyday processes, such studies may ultimately lead to technological advances. This project will integrate research and teaching by training graduate students in an interdisciplinary environment, and also by giving them experience in the use of cutting-edge synchrotron facilities. The training will prepare them for a range of careers in academe, industry and government.This research is focused on the investigation of interfacial order in liquids,. Many experiments have shown that the properties of liquids near interfaces are often different from those of the bulk liquid; this implies that the arrangement of liquid molecules changes near interfaces. Recent work from this group has shown that it is possible to use synchrotron X-rays to directly observe these rearrangements. In the current project, order in molecular liquids near interfaces will be studied, and the dependence of the observed ordering on substrate surface structure and shear rates will be investigated in detail. The knowledge gained from such studies will help us better understand how and why liquids behave differently at interfaces, and thus ultimately help design specific interfacial liquid properties. Since interfacial liquids play crucial roles in many familiar processes such as lubrication, adhesion, filtration, oil recovery, wetting/spreading/coating, etc., such studies may ultimately lead to benefits to society from improvements in these processes. This project will integrate research and teaching by training graduate students in an interdisciplinary environment, and also by giving them experience in the use of cutting-edge national synchrotron facilities such as the Advanced Photon Source and the National Synchrotron Light Source. This training will prepare them for a range of careers in academe, industry and government.