微流体制备三重态光敏活性集光微囊反应器及其性质研究

Light is one of the most important sources of energy on the earth. Construction of reaction systems which integrated light harvesting microstructure and photochemical activity is of great importance. For the purpose, learning from the processes and mechanisms of harvesting, transmitting and utilizing light in organisms through supramolecular assembly and polymerization becomes one of the most important means to improve the efficiency of photoreactions. In this project, we combine colloid and interfacial chemistry, photochemistry and microfluidics technology. We design photosensitive reaction systems with high efficiency light harvesting ability, diffusibility and photocatalytic activity to do the research work by using the following methods. Firstly, we are using microfluidics and interfacial chemistry as preparation techniques. Secondly, we construct light-harvesting microcapsules which are hollow and porous as material carriers. Thirdly, we are using photosensitizers with high efficiency triplet yield as active sites. To improve the utilization efficiency of light, one needs understanding of both the physical structure of microcapsules and binding propertives of the different photosensitizers.Therefore, mastering the regulation and utilization of photons at multi-scales can better construct clear physical and chemical models for the heterogeneous photocatalysis, and also provide theoretical bases for the fabrication of related photosensitive systems. The realisation of this project will help to establish simple methods for building of high-efficiency photosensitive microcapsule reactors. Moreover, deeper knowledge of the mechanisms of finite space/sensitizers interaction is crucial for further fabrication of advanced supramolecular photochemical systems.

光是地球上最重要的能量来源之一，借鉴生物体收集、传递和利用光能的过程和机制，通过超分子组装、高分子聚合等方法构筑同时具有集光微结构和光化学活性的反应体系成为当前提高光反应效率的重要手段之一。本项目将胶体与界面化学、光化学以及微流控技术相结合，以微流体和界面化学方法为制备技术，以集光空心多孔微囊为载体，以高性能三重态光敏分子为活性位点，设计具有高光子收集效率、高物质扩散能力和高光催化活性的反应体系。本课题从微囊的物理结构和光敏分子的化学性能两个方面提高光能利用率。掌握光子在不同尺度的调控和利用规律，可以更好地为多相光化学反应建立清晰明确的物理化学模型，为制备相关的光活性体系提供理论依据。该课题的设立与进行，一方面有助于建立高效光活性微囊反应器的普适制备方法，另一方面进一步探索限域空间对三重态光敏分子光活性影响的机制，可以为制备其他先进光化学组装体提供有益借鉴。

本项目以提高光反应效率为主线，将胶体与界面化学、光化学以及微流控技术相结合，构筑具有三重态光敏活性的集光微囊反应器，并在此基础上构筑了流动光催化体系，实现了高效多相光催化。在项目执行过程中，建立了制备结构可控空心微囊的普适性方法；通过分子设计合成了具有强系间窜越能力的多功能三重态光敏分子；运用微流体技术、光聚合技术成功实现了光敏剂的固载；结合超快光谱学等手段阐明了光敏分子在固相环境中的物理化学特性，发现该项目中使用的三重态光敏剂固载后激发态寿命大幅延长至毫秒级，有利于光催化反应的进行；运用激光直写技术与玻璃键合技术构建了流动光化学反应器，将集光微囊填装后进行流动多相光催化反应表现出了优异的催化性能，该多相反应体系的反应速率可达传统光催化剂参与的均相反应的45倍。该课题的开展，一方面使我们探索出了制备高效光活性微囊的普适性方法，另一方面有利于对限域空间内三重态光敏分子光物理性质的高效表达这一基础性问题进行研究，为先进光化学组装体，特别是多相光催化剂的构建提供有益信息。