IMR: Acquisition and Developing Femtosecond Nonlinear Spectroscopy Probing Structure and Moving Polymer Interfaces and Student Education

IMR：获取和开发飞秒非线性光谱探测结构和移动聚合物界面以及学生教育

• 批准号: 0526797
• 负责人: Ali Dhinojwala
• 金额: --
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0526797&HistoricalAwards=false
• 关键词: IMR; Acquisition; Developing; Femtosecond; Nonlinear

The objective of this proposal is to acquire and develop an ultra-fast femtosecond infrared-visible sum-frequency generation spectrometer (SFG) to probe the structure and dynamics of polymer molecules at moving interfaces encountered in the areas of friction, adhesion and dynamic surface tension. Past results using poly (dimethylsiloxane) (PDMS) lenses using Johnson-Kendall-Roberts technique and mica surfaces using surface force apparatus have found a relationship between friction, adhesion hysteresis and mobility of the molecules at the interface. Still, there is no direct information on the changes in the structure of molecules at moving or sliding interfaces. Recently, we have developed SFG in total internal reflection geometry to study hidden polymer interfaces and the preliminary results from the picosecond SFG system shows that it is possible to measure the changes in structure between two moving or sliding surfaces. The proposed broadband femtosecond system will provide the time resolution needed to measure rapid changes in structure at solid-solid, liquid-liquid and air-liquid contact interfaces to understand friction, adhesion and dynamic interfacial tension. The education and outreach activities will be offered to local schools in District 5 in order to promote an interest in science by encouraging students to undertake science projects and compete at district, state and international level. Friction, adhesion and dynamic surface tension between surfaces are of utmost importance in a variety of technological and biological applications. Tires on roads, windshield wipers, and movement of human joints are some examples where friction and adhesion are experienced. This field, for a long time, has relied only on force measurements to interpret the molecular mechanism involved in these processes. This proposal provides a new experimental method based on nonlinear optics and contact mechanics to probe the molecular motion or deformation at the interface during sliding. The understanding and control of these phenomena will have a tremendous impact in conserving and using precious energy resources. This research will influence our design of surfaces, lubricants and micro or nano-actuators. The education and outreach activities will be offered to local schools in District 5 in order to promote an interest in science by encouraging students to undertake science projects and compete at district, state and international level.

该提案的目的是获得和开发超快飞秒红外-可见和频发生光谱仪（SFG），以探测摩擦，粘附和动态表面张力领域中遇到的移动界面处聚合物分子的结构和动力学。 过去的结果使用聚（二甲基硅氧烷）（PDMS）透镜使用约翰逊-肯德尔-罗伯茨技术和云母表面使用表面力装置已经发现摩擦，粘附滞后和流动性的分子在界面之间的关系。 尽管如此，在运动或滑动界面上分子结构的变化仍然没有直接的信息。 最近，我们已经开发了全内反射几何SFG研究隐藏的聚合物界面和皮秒SFG系统的初步结果表明，它是可能的，以测量两个移动或滑动表面之间的结构变化。 拟议的宽带飞秒系统将提供所需的时间分辨率，以测量固体-固体，液体-液体和空气-液体接触界面的结构的快速变化，以了解摩擦，粘附和动态界面张力。 教育和推广活动将提供给当地学校在第5区，以促进对科学的兴趣，鼓励学生进行科学项目，并在地区，国家和国际一级的竞争。表面之间的摩擦、粘附和动态表面张力在各种技术和生物应用中至关重要。 道路上的轮胎、挡风玻璃刮水器和人体关节的运动是经历摩擦和粘附的一些示例。长期以来，该领域仅依赖于力测量来解释这些过程中涉及的分子机制。 该方案提供了一种新的基于非线性光学和接触力学的实验方法，以探测滑动过程中分子在界面处的运动或变形。 对这些现象的理解和控制将对节约和利用宝贵的能源资源产生巨大影响。 这项研究将影响我们的表面，润滑剂和微或纳米致动器的设计。教育和推广活动将提供给当地学校在第5区，以促进对科学的兴趣，鼓励学生进行科学项目，并在地区，国家和国际一级的竞争。