Quartz Crystal Microbalance Studies of Atomic-Scale Friction

w：\awards\awards96\num.doc 9705259 Krim这个实验研究项目的重点是原子尺度的摩擦现象的理解，包括那些在液体-固体界面。石英晶体微量天平的一组实验 （QCM） 研究 的 摩擦 在 将执行受控的环境条件和良好限定的接触几何形状。 其中一些旨在探索滑动界面处能量传递的基本机制，而另一些将研究与实际工程应用相关的模型润滑系统。待研究的一个系统由选定的稀有气体和烷烃层在清洁的（111）金属表面上滑动组成。研究中的模型润滑系统包括与液体接触的原子均匀的C60表面;以及与液体接触的原子均匀的己烷和合成润滑剂。 均匀的金属表面。 在后一 感兴趣的系统性质包括紧邻表面形成的分子薄润滑剂层的粘度和滑动，这些主题与弹性流体动力学和边界润滑之间的过渡区域中的润滑剂性能有关。 该实验研究项目致力于提高对摩擦力和相关热效应的科学认识。 这些影响的基本原子尺度的理解，寻求利用先进的实验技术，包括石英晶体微量天平（QCM），可以检测单原子单层。这项工作的重点是在滑动摩擦过程中的能量传递机制;和液体润滑剂的粘性和弹性性能接近固体表面。 对这一点的理解的提高是非常重要的，因为涉及机械运动的技术范围很广 和 具有重要的经济意义。 的 工作 是跨学科的性质，在这个程序的研究生将接受优秀的教育，准备他们在工业，政府或教育就业。 ***

w:\awards\awards96\num.doc 9705259 Krim This experimental research project focuses on the atomic scale understanding of frictional phenomena, including those at liquid- solid interfaces. A set of experiments involving quartz crystal microbalance (QCM) studies of friction in controlled environmental conditions and well-defined contact geometries will be performed. Some of these seek to explore the fundamental mechanisms of energy transfer at a sliding interface, while others will investigate model lubrication systems which are of relevance to actual engineering applications. One system to be studied consists of selected rare gas and alkane layers sliding on clean (111) metal surfaces. Model lubrication systems under study include atomically-uniform C60 surfaces in contact with a liquid; and hexanes and synthetic lubricants in contact with atomically uniform metal surfaces. In the latter systems properties of interest include the viscosity and slippage of molecularly thin lubricant layers forming immediately adjacent to the surface, topics which are related to the performance of a lubricant in the transition region between elastohydrodynamic and boundary lubrication. %%% This experimental research project is devoted to improving the scientific understanding of friction forces and related heating effects. An understanding of these effects on the basic atomic scale is sought, making use of advanced experimental techniques, including the quartz crystal microbalance (QCM) which can detect single atomic monolayers. The work focuses on mechanisms of energy transfer during sliding friction; and the viscous and elastic properties of liquid lubricants close to a solid surface. Improvements in understanding here can be of great importance, because the range of technology involving mechanical motions is broad and has great economic importan ce. The work is interdisciplinary in its nature and the graduate students in this program will receive an excellent education preparing them for employment in industry, government or education. ***