Single Molecule Studies of Molecular Motions Near the Glass Transition

本项目由化学学部实验物理化学项目资助，研究材料玻璃化转变附近的空间非均质性。单探针分子的荧光嵌入感兴趣的系统将用于异质环境的直接表征。本研究将解决三个主要问题：1)异质性如何在不同的长度尺度上表现出来？2)非均质性与原玻璃的易碎性有何关系？3)邻近异质区域的动态是否相关？聚苯乙烯和甘油将是嵌入不同大小探针分子的主要玻璃形成物。参与本研究的学生将获得当代物理化学领域的宝贵经验，为他们在学术、政府或工业经济部门的进一步学习或就业做好准备。

This project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, deals with the spatial heterogeneities in materials near their glass transition. The fluorescence of single probe molecules embedded in the system of interest will be used for the direct characterization of the heterogeneous environments. Three main issues will be addressed in this work: 1) How does heterogeneity manifest itself on different length scales? 2) How is the heterogeneity related to the fragility of the glass former? 3) Are the dynamics in neighboring heterogeneous regions correlated? Polystyrene and glycerol will be the principal glass-formers in which probe molecules of different sizes are embedded. The students who participate in this research will gain valuable experience in a contemporary area of physical chemistry that will prepare them for further study or employment in the academic, government or industrial sectors of the economy.