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

在本项目中，我们研究了内表面具有不同刚性或亲水性的几何约束下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来探测所研究系统中的局部介电或机械响应。除了硬二氧化硅气孔作为限制材料外，还将在微乳液液滴内(软限制)和在蛋白质存在下(内部限制)研究含水混合物。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的动力学与限制系统内的平均动力学。此外，由于该方法的局部性，TSD能够探测微乳液液滴内部的动力学行为，而不依赖于液滴的整体运动，这是只用很少的实验方法就能做到的。在第一个供资期间，开发和应用了量子光学技术，以扩大TSD方法的可及时间范围。因此，可以应用延长时间窗的TSD，以分离表面、密度和有限尺寸对约束动力学的影响，并最终实现对氢键液体在日益复杂的约束中的动力学的理解，包括与生物或技术相关的约束情况。

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.