用于液体硝基爆炸物检测的Mg-MIL-53系列微孔材料的设计、合成及性能研究

The design and fabrication of chemical sensors with high sensitivity and selectivity have attracted extensive attention since they play a great role in anti-chemical and biological weapons, non-metallic mine detection, especially in anti–terrorism. Compared to solid explosives, liquid explosives are welcome by terrorist due to simple composition to be manufactured, very strong explosion and easier camouflage to escape the check of the security. The aim of this project is to design and synthesize new Mg-MIL-53 analogue microporous materials with the variable pore size and the aromatic wall through changing the kinds of ligands, which are used as the adsorbent for a reversible selective adsorption and separation of liquid nitro-based explosives including nitrobenzene (NB), nitromethane (NM), nitroethane (NE) and two nitropropane (NP) isomers, and the sensing function is investigated to detect rapidly the nitro-based explosives in the vapor phase based on the principle of fluorescence quenching. Density functional theory (DFT) calculations also explain that the dynamic quenching mechanism for the formation of the emission spectra of the main framework fluorescent Mg-MIL-53 microporous materials influenced by the nitro-based explosives, determination of the HOMO and LUMO energy levels, the selection of a new generation of sensitivity high, the easy detection test of the nitro-based explosives fluorescent chemical sensing devices, in order to be effective to preventing terrorists。

随着反恐、反化学生物武器、非金属地雷探测等需求增加，世界各国对各类高性能传感器研究愈来愈重视。相对于固体炸弹, 液体炸弹成分简单更容易制造,爆炸威力极强，更易于伪装逃脱安全部门的检查。本项目拟通过改变配体的种类、设计和合成孔道尺寸和孔道壁芳香性可调的Mg-MIL-53系列新型MOFs微孔材料，将其作为吸附剂在液相中对硝基类爆炸物(如：硝基苯 NB,硝基甲烷 NM，硝基乙烷 NE和同分异构体的硝基丙烷NP)进行选择性可逆的吸附-解吸附，有效的分离，并深入探讨基于荧光淬灭原理的检测痕量气相中硝基类爆炸物感应性能。DFT理论计算揭示硝基爆炸物对Mg-MIL-53微孔材料的主体框架荧光发射光谱的动态淬灭的形成机制，确定其HOMO和LUMO能级，遴选出新一代灵敏度高、测试方法简便的检测硝基爆炸物的荧光化学感应器件。

在本项目的研究中，通过调控试验条件，我们成功利用长度和构象相互匹配的有机配体(带有两个μ2-O基团的电中性吡啶氮氧BPNO和二元有机羧酸BDC)作为基本构筑单元合成出新型的Mg-MIL-53的系列MOFs微孔材料，借助氢键和π-π作用的强弱的差异可以实现对硝基爆炸物NB, NM，NE和同分异构体的NP的有效分离。项目实施过程中，共在学术期刊上发表学术论文10篇标注本项目基金资助的SCI论文，培养1名博士和3名硕士研究生，基本完成了本项目的预期目标，为研发出新一代便携式的检测液体硝基爆炸物的探测仪提供技术储备。需要指出的是我们的研究工作与预期目标之间也有一定的差距，主要体现在：（1）带有两个μ2-O基团的配体，尤其是适用于制备系列化合物的配体方面开展了大量的研究工作，总体进展情况不太满意，未能找到比中性吡啶氮氧BPNO配体更适合合成Mg-MIL－53材料的配体；（2）检测液体硝基爆炸物过程中，未能检测大分子硝基化合物。我们目前正在开展的研究工作表明，这些存在的问题有可能通过后续的研究工作得到解决。