Heterogeneous Dynamics in Disordered Materials by Spectroscopy

CHE-0204065PI：Richert，Ranko在这个由化学部实验物理化学计划资助的项目中，Richert将使用三重态溶剂化动力学进行研究，以研究玻璃形成液体中的松弛和动力学不均匀。将在微秒到纳秒的时间尺度上对探针旋转、溶剂化时间关联函数的偏振角相关函数的检测以及非均质性进行实验。Richert开发的一项新技术首次可以同时测量探针的旋转动力学和溶剂化动力学。这个项目涉及过冷液体如何转变为凝聚的固态这一重要课题。以前的许多实验已经指出，在均匀的液体中存在非均相区，非均相区表现出与均质区不同的动力学行为。首席研究人员发明了一种独特的技术，通过这种技术，可以在一次实验中分别获得非均质区域的性质和均匀区域的性质。这项研究有望在理解液体到玻璃转变方面取得重大进展，并有可能应用于聚合物科学和塑料晶体。学生将参与这项研究。

CHE-0204065PI: Richert, RankoIn this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Richert will perform research using triplet state solvation dynamics to study relaxation and dynamical heterogeneity in glass-forming liquids. Experiments will be performed on probe rotation, polarization-angle-dependent detection of the solvation time correlation function, and heterogeneity on the microsecond to nanosecond time scales. A new technique developed by Richert allows the first simultaneous measurement of probe rotational dynamics and solvation dynamics. This project deals with the important topic of how supercooled liquids make a transition to the solid state of aggregation. Many previous experiments have pointed to the existence of heterogeneous regions in the otherwise homogeneous liquid, with the heterogeneous regions exhibiting different dynamical behaviors from the homogeneous ones. The principal investigator has invented a unique technique by means of which the properties of the heterogeneous regions can be obtained separately from the homogeneous ones in a single experiment. Great advances in the understanding of the liquid to glass transition are expected to result from this research, with potential applications to polymer science and plastic crystals. Students will participate in this research.