Development of an Ellipsometric Microscope for Measuring Liquid Surface Structure

第9625867号法律 液滴的结构或液体表面处的膜的纹理指示下面的表面相互作用力、线张力和表面弹性。表面相互作用的理解在许多物理，化学和生物过程中是重要的。 例如，表面相互作用控制常用作生物膜模型系统的朗缪尔膜的相图，表面相互作用还控制液滴的铺展性质，这在理解润滑中是重要的，类似地，表面相互作用影响在许多现代光学器件中使用的液晶分子的取向。 因此，有许多科学和技术上的重要原因，研究液滴的结构和液体表面的膜的纹理。 有了这个奖项，我们将开发一种改进的椭偏显微镜来研究液体表面结构。 它克服了与以前的椭偏显微镜设计，只能研究固体表面上的薄膜或液滴相关的各种技术困难。 对于液体表面的各向同性膜或液滴，改进的椭偏显微镜可以以~ 0.1nm的厚度分辨率和~1 μ m的空间分辨率确定膜厚度作为位置的函数，而对于液体表面的已知厚度和组成的各向异性膜，椭偏显微镜可以以~ 1 μ m的空间分辨率确定膜各向异性的变化。 该仪器将用于研究润湿液滴在凝聚成均匀润湿膜时的成核和生长。 该仪器还将用于研究已知厚度的自由悬浮液晶膜中的拓扑缺陷。 向错和位错的解束缚被认为在自由悬浮液晶膜的二维熔融过程中起着重要作用。 据我们所知，这将是第一台能够以微米级空间分辨率测定各向异性薄膜的绝对倾斜角的仪器（前提是薄膜厚度已知）。 因此，这一工具应证明在科学和工业界感兴趣的许多其他情况下具有普遍用途。 例如，它可以用来研究倾斜角转变和朗缪尔薄膜中的缺陷。 它还可以用于监测工业或研究环境中各向异性薄膜的质量控制，例如，它可以量化高温超导薄膜或Langmuir-Blodgett层的均匀性。 ***

Law 9625867 The structure of droplets or the texture of films at liquid surfaces are indicative of the underlying surface interaction forces, line tension and surface elasticity. The understanding of surface interactions is important in many physical, chemical, and biological processes. For example, surface interactions control the phase diagram of Langmuir films which are frequently used as model systems for biological membranes, surface interactions also control the spreading properties of a liquid droplet which is important in the understanding of lubrication, similarly surface interactions influence the orientation of liquid crystal molecules which are used in many modern optical devices. There are therefore many scientific and technologically important reasons for studying the structure of droplets and the texture of films at liquid surfaces. With this award, we will develop an improved ellipsometric microscope to study liquid surface structure. It overcomes various technical difficulties associated with a previous ellipsometric microscope design which could only study thin films or droplets on solid surfaces. For isotropic films or droplets at liquid surfaces the improved ellipsometric microscope can determine the film thickness as a function of position with ~0.1 nm thickness resolution and ~1 um spatial resolution, while for anisotropic films of known thickness and composition at a liquid surface the ellipsometric microscope can determine the variation in film anisotropy with ~l um spatial resolution. This instrument will be used to study the nucleation and growth of wetting droplets as they coalesce to a uniform wetting film. The instrument will also be used to study topological defects in freely suspended liquid crystal films of known thickness. The unbinding of disclinations and dislocations is believed to play an important role in the 2-D melting process of freely suspended liquid crystal films. %%% As far as we are aware this will be th e first instrument of its kind which can determine the absolute tilt angle of anisotropic films with micrometer spatial resolution (provided the film thickness is known). This instrument should therefore prove of general use in many other situations of interest to the scientific and industrial community. For example, it could be used to study tilt angle transitions and defects in Langmuir films. It could also be used in monitoring the quality control of anisotropic films in an industrial or research setting, for example, it can quantify the uniformity of hightemperature superconducting films or Langmuir-Blodgett layers. ***