Long range orientation correlation in liquids

本项目由美国内华达大学拉斯维加斯分校化学结构、动力学和机理项目资助，由David Shelton教授进行一系列非线性激光散射实验，探索分子液体的结构。人们普遍认为，液体中分子间的位置和取向关系最多延伸到几个分子直径，但与此相反，二次谐波光散射揭示了许多液体中几十到几百个分子直径距离上的分子取向关系。二次谐波光散射的偏振依赖性提供了一种独特灵敏的远程极性分子序探测方法。本研究旨在测量液体中远端分子取向相关性的强度、范围和形式，并了解这些相关性的起源和后果。纳米尺度的液体和系统在物理、化学和生物学中具有广泛的重要性和当前的兴趣。这一研究结果将对包括水在内的许多常见液体中以前未观察到的纳米尺度结构产生广泛的基础和应用化学研究影响。研究生和本科生将参与这项研究，并将接受最先进的激光散射技术的培训。

In this project funded by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division, Professor David Shelton of the University of Nevada Las Vegas will conduct a series of nonlinear laser light scattering experiments to probe the structure of molecular liquids. Contrary to the generally accepted view that intermolecular position and orientation correlations in liquids extend at most a few molecular diameters, second-harmonic light scattering reveals molecular orientation correlation at distances of tens to hundreds of molecular diameters in many liquids. The polarization dependence of second harmonic light scattering provides a uniquely sensitive probe of long-range polar molecular order. This study aims to measure the strength, range and form of the long-range molecular orientation correlations in liquids, and to gain an understanding of the origin and consequences of these correlations. Liquids and systems of nanometer scale are of wide importance and current interest in physics, chemistry and biology. A wide range of basic and applied chemical research will be impacted by the results of this investigation of previously unobserved structure at the nanometer scale in many common liquids including water. Graduate and undergraduate students will participate in this research, and will be trained in state-of-the-art laser light scattering techniques.