基于分子设计的有机硅荧光多孔材料的制备及其性能研究

Organosilicon fluorescent porous materials could be potentially applied in many areas including gas storage and separation, light harvesting and sensors, etc. However, this class of materials has been rarely investigated. More importantly, the mechanisms of the performance adjustment and silicon-based effect are still not clear. Motivated by the present situations, in this project novel organosilicon fluorescent porous materials will be firstly synthesized through organic polymerization reactions based on cubic polyhedral oligomeric silsesquioxane or tetrahedral silanes as the organosilicon units and fluorescent units from the molecule-design standpoint. The performances of the resulting materials will be efficiently adjusted by three means: (i) optimizing reaction method; (ii) selecting different fluorescent monomers; and (iii) introducing the third monomers. The mechanism of performance adjustment will be explored. The performances will be compared with or without introducing the organosilicon units in the materials and the mechanism that how silicon atom affects the performance will be investigated. Thus the “silicon-based effect” will be disclosed. Finally, according to the characteristics of the materials’ properties, they will be utilized as promising candidates for carbon dioxide capture, nitroaromatic explosives detection and protein detection, etc. After the completion of the project, diversified organosilicon fluorescent porous materials with extensively potential applications will be achieved. By means of exploring and concluding the mechanisms of performance adjustment and “silicon-based effect”, the results could provide significant guidance to rationally design and develop novel analogues with high performance and control their functionalities. Moreover, this research could give important experimental data and theoretical references for enclosing the essential differences between organosilicon materials and carbon-based materials.

有机硅荧光多孔材料在气体储存分离、光捕获、传感器等领域具有潜在的广泛应用。针对目前国内外研究较少、且对材料性能调控及硅原子在材料中的作用机制尚不清晰的现状，本课题从分子设计层面出发，以多面体低聚倍半硅氧烷或四面体硅烷为有机硅单元，选择荧光单元，通过有机聚合反应制备新型有机硅荧光多孔材料；通过优化反应条件、选择荧光单体和引入第三单体三种方法调控材料性能，并研究其调控机理；对比有机硅单元引入前后材料性能的变化，研究硅原子在材料中的作用机制，挖掘“硅基效应”；根据材料性能特点，将其应用于二氧化碳捕获、硝基芳烃类爆炸物检测及蛋白质检测等领域。课题的完成将得到多种具有广泛应用前景的有机硅荧光多孔材料，通过探索归纳调控机理及“硅基效应”，对理性设计和研发高性能的同类材料和控制材料功能起到重要的指导意义，为揭示有机硅材料与碳材料的本质区别提供重要的理论参考和实验依据。

有机硅荧光多孔材料在气体储存分离、光捕获、化学传感器等领域具有广泛应用前景，但目前国内外研究较少、且对材料性能调控及有机硅单元在材料中的作用机制尚不清晰。本项目从分子设计层面出发，主要开展了以下工作：1）以八面体低聚倍半硅氧烷等为有机硅单体，选择螺二芴、芘、四苯基乙烯等荧光单元，通过Heck等有机聚合反应制备了二十余种有机硅荧光多孔材料。2）通过改变反应条件、选择荧光单体和引入第三单体实现对材料的多孔性能和荧光性能的调控。研究发现，BET比表面积和孔体积分别最高达到876 m2 g-1和1.50 cm3 g-1，并随着荧光单体的选择和引入第三单体，表现出从蓝光到红光区的改变（464~602nm），并具有较高的绝对量子产率（最高到22.42%）。更重要的是，改变反应条件后材料表现出从几乎无荧光到强荧光的变化，对比后揭示了影响荧光性能的关键因素，即三乙胺、P(o-CH3Ph)3及钯黑等在反应过程或产物中残留造成的荧光猝灭，进一步找到了此类材料的原始形貌，解释了目前许多共轭微孔聚合物无荧光或弱荧光的现象。3）利用多孔性能，将材料用于CO2捕获，最高吸附量达到1.56 mmol g–1（273K/1bar），并利用POSS单元在弱碱性下部分断裂的特点，发展了第一例具有同时提高多孔性和CO2吸附性能的有机硅多孔材料；利用荧光性能，通过荧光猝灭现象将材料用于爆炸物检测，构建了一种能快速、灵敏、简便、直观检测的荧光试纸，发现对各类爆炸物均具有灵敏的检测效果，尤其是三硝基甲苯和苦味酸，不仅能够选择性检测且具有很低的检测限（4.43ppb，检测试纸对苦味酸）。4）研究内容拓展。将POSS基荧光多孔材料与聚硅氧烷复合，实现了其可加工性，得到了一系列新型有机硅荧光弹性体，并将其用于制备显示各种颜色的紫外发光二极管；将巯基氧化偶联反应用于制备POSS基多孔材料，所得材料虽然多孔性能低，但能作为高效吸附剂用于染料废水处理，选择性吸附阳离子染料；发展了巯基-双键反应制备有机硅聚合物，发现硅氧键聚集诱导的非典型荧光增强现象。通过本项目的实施，不仅得到多种具有广泛应用前景的新型有机硅荧光多孔材料，通过性能调控揭示了影响多孔和荧光性能的关键因素，为理性设计和制备高性能的同类材料和控制材料功能起到重要的指导意义。在本项目的资助下，发表SCI论文14篇，申请发明专利6项，授权1项，完成了项目任务书目标。