金属-有机框架薄膜器件的制备及其对硝基芳香分子的荧光传感研究

Developing new portable sensing materials towards high explosives has attracted considerable interests owing to social security, environmental and humanitarian implications. This project is aimed at fabricating new sensing devices toward Nitroacromatic explosives using porous MOFs with fluroscent sensing properties as the precusors. Based on the redox queching mechanism of fluroscence, we will firstly study to design and synthesize rigid aromatic ligands which have carboxylic acid groups and π electrons. The ligands will be used to react with 3d-4f metal ions through self assemble process to construct porous MOFs which have fluorescent sensing properties towards nitroaromatic explosives. Next, by employing the surfactant and/or capping agent assisted methods, nano-particles of the above sensing MOFs will be synthesized, which will be used to fabricate fluorescent thin film devices through thermal deposition, spin coating,dip coating etc. The resulted thin film devices will have promotions both in sensing ability and portability. On the base of the synthesizing work, we will focus on the study of the relationship between the device's sensing ability and the synthesis parameters, which refer to the identity of ligand, MOFs building strategy and the fabrication of the thin film. The understanding of this relationship will help us to illustrate the regularity of the device's sensing behavior when the lignd/MOF structure or the thin film's morphology changes, so that we can build up a methodolgy which can systematically tune the device's sensing ability. If this project can be successfully carried out, it will realize the application of MOFs materials in the field of explosive sensing by the means of nano thin films, which is a whole new way to present the MOFs' sensing abilities. The result will expand the research directions of fluorescent sensing MOFs, and will provide preliminary foudation for the exploring of practical explosive sensing devices.

发展新型便携高效的爆炸物检测材料对社会安全及环境污染控制有着重要的现实意义，本项目旨在利用多孔MOFs材料的荧光传感性质开发新型的硝基芳香爆炸物的荧光薄膜检测器件。依据荧光的氧化还原猝灭机理，设计合成富含π电子的刚性羧酸配体，以3d-4f金属为节点，自组装得到荧光MOFs传感材料。之后采用表面活性剂、阻聚剂辅助等手段，合成其纳米颗粒，并通过热沉积、旋涂及提拉等方法，制备得到纳米荧光薄膜器件，使得材料在检测性能、便携性等方面得到极大提升。在合成工作基础上，重点关注配体结构、MOFs构筑方法及薄膜的制备手段对检测性能的影响，阐明配体结构、MOFs结构及薄膜形貌与检测性能之间的关系，系统建立调控纳米荧光薄膜器件检测性能的方法。本项目以纳米薄膜的形式实现MOFs材料在易爆物检测方面的应用，创新拓展了MOFs荧光传感材料的研究思路，为将来开发生产实用型爆炸物检测器件提供初步的理论研究基础和实验支持。

硝基芳香化合物对于环境、人体及国土安全均有重要影响，本课题着眼于目前的社会需求及科研发展前沿，以功能金属-有机框架材料（MOFs）为研究对象，探索MOFs及其薄膜器件对硝基芳香化合物的荧光传感应用。（1）我们首先选择蒽为核心单元，衍生得到9,10-二丙烯酸蒽，通过与3d过渡金属通过溶剂热法自组装得到一系列MOFs材料，分别通过单晶X-射线衍射，PXRD，热重，红外等手段表征分析MOFs的结构。研究发现，Cd构筑的材料ADA-Cd表现出十分奇特的光学性质，制备成薄膜器件后可以实现预期的荧光传感硝基芳香分子，还表现出奇特的过氧草酸酯化学发光特性，成为该领域的首个MOF案例。此外，该材料与TiO2共同作用可以实现可见光下的高效光催化降解染料。该材料为新型荧光传感器、化学冷光源及光催化剂的研究指明了方向；（2）当把节点更换为Mn后，相应的材料ADA-Mn不仅表现出非常优秀的硝基芳香分子传感能力，还表现出十分罕见的聚集诱导发光，可以实现在0-100%的浓度范围内迅速准确测定CO2的浓度，是首个具有CO2荧光传感能力的MOF材料，为新型CO2传感器的开发提供了思路；（3）利用N杂四并苯配体与Ag构筑的材料DAT-AgN表现出十分罕见的二氯甲烷荧光传感能力，当其薄膜器件暴露在二氯甲烷蒸气中时其荧光发射实现从无到有的巨大转变，是新一代的VOCs荧光探针材料；（4）还尝试引入新型的含N柔性配体，与3d金属构筑了多个新型功能MOFs材料，表现出极强的吸附、催化及化学发光传感特性。总体来说，本课题的研究基本按照申请书中的内容执行，圆满完成了预订的任务目标，获得了大量宝贵实验数据，为后续研究工作的开展打下基础并指明方向。部分研究成果分别发表在Adv. Funct. Mater.及Chem. Eur. J.等期刊上，申请发明专利5项，授权1项，发表会议论文2篇，多次应邀参加国内外会议交流研究成果，应邀作会议报告1次，获国际会议优秀海报奖1次，研究成果被Materials Views China等国内外多个知名科研门户网站转载宣传。