Triplet State Solvation Dynamics of supercooled water-based binary liquids in hard and softconfinement

点击翻译按钮获取中文摘要

In the present project we study phase behaviour and slow dynamics of supercooled aqueous mixtures in geometric confinement with varying rigidity or hydroaffinity of the inner surface. The experimental method central to this project is triplet state solvation dynamics (TSD), which, depending on the dye molecules used, probes the local dielectric or mechanical response in the system under study. Besides hard silica pores as confining materials, aqueous mixtures will be investigated inside microemulsion droplets (soft confinement) and in the presence of proteins (intrinsic confinement). In particular, we plan to take advantage of the local character of the TSD method, which allows under certain circumstances to distinguish between the dynamics of molecules close to the inner surface from the average dynamics within the confining system. Moreover, due to the local character of the method, TSD is able to probe the dynamical behaviour inside microemulsion droplets independent of the motion of the droplet as a whole, something which is possible with only very few experimental methods. During the first funding period, quantum optical techniques were developed and applied to extend the accessible time range of the TSD method. Thus, it becomes possible to apply TSD with extended time window in order to separate surface, density and finite size effects on the dynamics in confinement and to approach an understanding of the dynamics of hydrogen bonding liquids in increasingly complex confinements finally including biologically or technologically relevant confinement situations.