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

在本项目中，我们研究了几何约束下具有不同刚性或内表面亲水性的过冷水混合物的相行为和慢动力学。这个项目的核心实验方法是三重态溶剂化动力学（TSD），它根据所使用的染料分子，探测被研究系统中的局部介电或机械响应。除了硬硅孔作为约束材料外，还将研究微乳液滴内的水混合物（软约束）和存在蛋白质的水混合物（本征约束）。特别是，我们计划利用TSD方法的局部特性，它允许在某些情况下区分靠近内表面的分子动力学和封闭系统内的平均动力学。此外，由于该方法的局部特性，TSD能够探测微乳液滴内部的动态行为，而不依赖于液滴的整体运动，这在很少的实验方法中是可能的。在第一个资助期内，量子光学技术被开发并应用于扩展TSD方法的可访问时间范围。因此，有可能应用具有延长时间窗口的TSD，以分离限制中表面、密度和有限尺寸对动力学的影响，并接近理解日益复杂的限制中氢键液体的动力学，最终包括生物或技术相关的限制情况。

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.