纤维素基固态荧光材料的结构设计、合成及应用探索

The common luminogens with planar π-conjugation structures tend to aggregate together and trigger off the well-known aggregation caused quenching (ACQ) of fluorescence in highly concentrated solutions, which has been a serious bottleneck for their application in the solid-state. In this project, we will focus on “how to eliminate ACQ phenomenon” and “how to utilize ACQ luminogens”. Taking advantage of unique structure and properties, such as regularly dispersed reactive numerous hydroxyls, good processibility in film and fiber, and excellent biocompatibility, we will selectively introduce ACQ luminogens into cellulose backbone by homogeneous chemical reactions. By controlling the distance of luminogens to inhibit their ACQ effect, novel cellulose-based solid fluorescent materials from ACQ luminogens will be created. And the effect of the chemical and spatial structure on fluorescent properties of the as-prepared products will be investigated systematically, in order to understand the mechanism of “how to eliminate ACQ phenomenon” and obtain a universal method to eliminate or mitigate ACQ phenomenon. Further, various fluorescent groups and functional groups will be introduced into cellulose skeleton based on this method, consequently a series of multifunctional cellulose-based solid fluorescent materials will be synthesized. And their application in imaging, sensing and security printing will also be investigated. Combining the cellulose, the most abundant natural polymer on the earth, and conventional ACQ luminogens, this research will open up a new opportunity to design and synthesize new organic solid fluorescent materials with multifunctional properties, and broaden the applications of both cellulose and ACQ luminogens.

具平面共轭结构的常见有机荧光分子在高浓溶液和固态下会产生荧光淬灭，即人们熟知的聚集诱导淬灭（ACQ）现象，限制了这类分子在固态材料中的应用。本课题从“克服传统荧光分子ACQ现象”基本问题出发，利用纤维素独特的结构和性能，如周期性分布的反应性羟基、成膜和成纤性好、生物相容性好等，通过均相化学反应，将荧光分子选择性间隔引入到纤维素骨架，通过控制荧光基团的距离，克服ACQ现象，将ACQ分子转化为实用、易加工的固态荧光材料，并揭示分子结构和空间拓扑结构对这类材料荧光性能的影响规律。进一步地，引入不同荧光基团和功能基团，获得系列纤维素基固态荧光材料，探索其在智能响应、荧光防伪、诊疗成像、特异性抗菌材料等领域的应用。本研究将自然界最丰富的天然高分子-纤维素和价廉、易得的ACQ荧光分子有机结合，有望获得系列新结构和新功能的固态荧光材料，拓展纤维素和ACQ分子的应用领域，有重要的学术价值和应用前景。

本课题从“克服传统荧光分子ACQ现象”基本问题出发，利用纤维素独特的结构和性能，如周期性分布的反应性羟基、成膜和成纤性好、生物相容性好等，通过均相化学反应，将荧光分子选择性引入到纤维素骨架，设计合成了系列新型纤维素基荧光材料。系统表征了这类材料的结构与性能，并揭示分子结构和空间拓扑结构对这类材料荧光性能的影响规律。通过控制荧光基团的距离，克服ACQ现象，将ACQ分子转化为实用、易加工的固态荧光材料。进一步地，引入不同荧光基团和功能基团，获得系列纤维素基固态荧光材料，探索了其在智能响应、荧光防伪、成像、特异性抗菌材料等领域的应用。本研究将自然界最丰富的天然高分子-纤维素和价廉、易得的ACQ荧光分子有机结合，创建了系列新结构和新功能的固态荧光材料，拓展了纤维素和ACQ分子的应用领域，有重要的学术价值和显著的应用前景。