Condensed-Phase Dynamics by Ultrafast Nonlinear Spectroscopy

在这个由化学部实验物理化学计划资助的项目中，伯格将从事凝聚态化学的研究，即过冷和高粘度液体的快时间尺度动力学研究。将开发新的非线性光谱仪，并扩展现有方法。要研究高粘度液体和其他复杂材料中的非均质性和非指数衰减，并进行旋转和溶剂化测量，并研究内部扩散转变。五阶旋转光谱(FORS)将被开发出来。一个新的粘弹性(VE)理论将被发展，该理论在统一的形式中同时包括惯性动力学和扩散动力学。这个项目处理流体行为中的重要问题，例如单分子动力学和流体集体行为之间的关系。现有的理论在解释流体的动力学性质方面取得了部分成功，目前的工作解决了过去只被略微处理过的基本问题。新的实验技术和理论将会被开发出来。这项研究将在研究生和本科生以及博士后研究助理的帮助下进行。他们将通过参与当代物理化学的前沿研究获得宝贵的经验。这些经验将对他们的进一步学习或在工业、政府实验室或学术界就业有很大的好处。

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Berg will undertake researches in condensed matter chemistry, namely fast time scale dynamics of supercooled and high viscosity liquids. New non-linear spectroscopies are to be developed and existing methods to be extended. Heterogeneity and non-exponential decays in high viscosity liquids and other complex materials are to be investigated, and rotation and solvation measurements are to be made and internal diffusive transitions invetigated. A Fifth Order Rotational Spectroscopy (FORS) is to be developed. A new viscoelastic (VE) theory is to be developed, one that includes both inertial and diffusive dynamics in a unified formalism.This project deals with important issues in the behavior of fluids, such as the relationship between the dynamics of single molecules and that of the collective behavior of fluids. Existing theories have been partially successful in accounting for the dynamical properties of fluids and the present work addresses fundamental issues that have in the past been treated only slightly. New experimental techniques, coupled with theory will be developed. This research will be conducted with the aid of graduate and undergraduate students, and postdoctoral research associates. They will gain valuable experience through their involvement in contemporary forefront research in physical chemistry. These experiences will of great advantage in their further studies, or employment in industry, government laboratories, or academia.