Heterogeneous Dynamics in Disordered Materials by Spectroscopy

在这个由化学部实验物理化学项目资助的项目中，Richert将使用三重态溶剂化动力学来研究玻璃形成液体的弛缓和动力学非均质性。实验将进行探针旋转、极化角相关的溶剂化时间相关函数检测以及微秒到纳秒时间尺度上的非均质性。Richert开发的一项新技术允许探针旋转动力学和溶剂化动力学的首次同时测量。这个项目涉及过冷液体如何过渡到固态聚集的重要主题。以前的许多实验都指出，在均匀的液体中存在非均匀区，非均匀区表现出与均匀区不同的动力学行为。首席研究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将非均质区与均质区分开获得。这项研究有望在理解液体到玻璃的转变方面取得巨大进展，并在聚合物科学和塑料晶体方面有潜在的应用。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.