Scanning Ripplon Microscopy

扫描波纹显微镜

• 批准号: 06555019
• 负责人: TAKAGI Kenshiro
• 金额: $ 6.08万
• 依托单位: UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06555019/
• 关键词: Ripplon; Surface Tension wave; Light Scattering; Langmuir Film; Liquid Surface Physics; Two-dimensional Phase Transition; Phase Separation; リプロンスペクトロスコピー; 光散乱測定; 光ヘテロダイン分光法; Ripplon; Surface Tension wave; Light Scattering; Langmuir Film; Liquid Surface Physics; Two-dimensional Phase Transition; Phase Separation; リプロンスペクトロスコピー; 光散乱測定; 光ヘテロダイン分光法

Langmuir film, a monolayr of molecules expanded on water surface, is important as a material for the LB film which has various industrial applications. The film shows phase transitions among two-dimensional gas, liquid and solid phases, and has attracted also a pure physical interest. In our previous studies we had established "Wide-band ripplon light scattering technique" for a non-contact measurement of ripplon, ie. high-frequency capillary waves thermally excited and propagating on water surface. This technique has been applied for investigating molecular dynamics in the Langmuir films ; local structure of the film, inhomogenuity and state of condensation have been revealed.The purpose of the present study is to develop "a ripplon microscope" by increasing spatial resolution of this light scattering technique and combining it with a surface scanning system. It would be useful for quantitative evaluation of the films by measuring the surface energy and the surface visco-elasticity, the values which sensitively reflect the state of monomolecular layr on water surface. It would provide us with a very effective means for structure analysis of Langmuir films. We also intended to clarify how the function of a LB film is determined by the structure and dynamics of the Langmuir film as its material.In this study we improved the signal processing and the optical system of the technique ; and constructed a surface scanning system. We succeeded in visualizing the surface structure with -10 mum spatial resolution and precision. We applied the new system for studying various effects of two-dimensional physics, including thermal expansion, and phase transitions. These results taught us an interesting fact two-dimensional substances also have critical phenomena as the more familiar three-dimensional ones, and their behavior is described within a framework of the mean field theory.

Langmuir膜是在水面上扩展的分子单层，它是具有各种工业应用的LB膜的材料。该膜显示了二维气体，液体和固体相之间的相变，并吸引了纯粹的物理兴趣。在以前的研究中，我们建立了用于对Ripplon的非接触式测量的“宽波兰光散射技术”。高频毛细管波热激发并在水面传播。该技术已用于研究Langmuir膜中的分子动力学。已经揭示了膜的局部结构，不稳定性和冷凝状态。本研究的目的是通过增加这种光散射技术的空间分辨率来开发“ ripplon显微镜”，并将其与表面扫描系统结合在一起。这对于通过测量表面能和表面粘弹性的定量评估将是有用的，该值敏感地反映了水面上单分子layr的状态。它将为我们提供一种非常有效的Langmuir膜结构分析手段。我们还旨在阐明LB膜的功能如何取决于Langmuir膜的结构和动力学作为其材料。在这项研究中，我们改善了信号处理和技术的光学系统。并构建了一个表面扫描系统。我们成功地以-10 MUM的空间分辨率和精度可视化表面结构。我们应用了新的系统来研究二维物理的各种影响，包括热膨胀和相变。这些结果教会了我们一个有趣的事实，二维物质作为更熟悉的三维现象也具有关键现象，并且在平均野外理论的框架内描述了它们的行为。