金属配位阳离子型自燃离子液体设计合成及催化燃烧机理研究

Hypergolic liquid propellant is of great significance to the developments of aerospace and national defense. The volatile and toxicity of the widely used hydrazine derivatives in liquid rocket is a serious environmental problem. Developing of eco-friendly hypergolic ionic liquids as replacements of hydrazine derivatives can solve this problem radically. To improve the ignition and combustion performances of hypergolic ionic liquids, metallic elements were introduced for designed syntheses of metal coordinated hypergolic ionic liquids due to their catalysis on combustion. A high speed photography and an infrared temperature-measuring technology will be applied to characterize the ignition and combustion performances of metal coordinated hypergolic ionic liquids, and the structure-performance relationship will be obtained. The decomposition mechanism of metal coordinated hypergolic ionic liquid and its’ reaction mechanism with nitric acid will be studied by Differential Scanning Calorimetry (DSC), Laser-Induced Breakdown Spectroscopy-Intensified CCD (LIBS-ICCD), Temperature-jump/Fourier Transform Infrared Spectroscopy (T-jump/FTIR), in situ-Fourier Transform Infrared Spectroscopy (in situ-FTIR) and Molecular Dynamics (MD). The catalytic mechanism of metal ions on the decomposition of metal coordinated hypergolic ionic liquid and its’ ignition and combustion reaction mechanism with nitric acid will be revealed. All the results could provide theoretical and experimental basis for further development of green hypergolic ionic liquids.

自燃液体推进剂对航天和国防事业的发展有重大意义，但目前广泛应用的肼类燃料面临易挥发、有剧毒的严重问题，开发环境友好的自燃离子液体替代肼类燃料可从根本上解决这一问题。本项目拟通过构筑金属配位阳离子，将金属元素引入自燃离子液体，设计合成金属配位阳离子型自燃离子液体，利用金属离子催化作用提升自燃离子液体性能；运用高速摄像和红外测温技术测试自燃离子液体的点火及燃烧性能，并揭示其结构性能关系；结合差示扫描量热(DSC)、激光诱导击穿光谱技术-动态图像及光谱系统(LIBS-ICCD)、快速热裂解/红外光谱技术(T-jump/FTIR)、原位红外光谱(in situ-FTIR)和分子动力学(MD)实验与计算手段，研究自燃离子液体分解过程及其与硝酸的自燃反应历程，揭示金属离子在金属配位阳离子型自燃离子液体自身分解及其与硝酸反应的点火及燃烧过程中的催化机理。为开发新型绿色自燃离子液体提供理论指导和实验依据。

绿色的自燃离子液体推进剂在自燃火箭发动机和飞行器姿态调控领域有重要应用前景。本项目通过配位键作用将金属元素引入到自燃离子液体中，以二氰胺根为活性阴离子，1-甲基咪唑、1-乙基咪唑、1-乙烯基咪唑、1-烯丙基咪唑为配体，Mn、Co、Ni、Cu为中心金属离子，设计合成出21种金属配位阳离子型自燃离子液体，采用X射线单晶衍射法准确测定了它们的晶体结构，并通过双配体或双金属的协同作用，进一步调节、提升自燃离子液体的点火燃烧性能；测试了金属配位阳离子型自燃离子液体与白烟硝酸的点火反应，它们均能与白烟硝酸发生自燃点火并持续燃烧，且具有较短的点火延迟时间；将获得的室温为固态的金属配位阳离子型自燃离子液体作为添加剂溶解到典型有机自燃离子液体1-烯丙基-3-甲基咪唑二氰胺盐中，通过添加剂种类和添加量的筛选优化，研制出多种性能优越的复合自燃离子液体，点火延迟时间从45 ms降低至6 ms，计算比冲达258 s，对复合自燃离子液体的热分解机理和非等温反应动力学参数进行了研究，分析了金属配位自燃离子液体的催化燃烧机理。项目研究成果对推动绿色自燃离子液体推进剂的发展有重要意义，为新型金属配位型自燃燃料的设计提供了新思路。项目资助发表学术论文25篇，包括Chemical Engineering Journal（4篇）、Inorganic Chemistry、Chinese Journal of Chemistry等，申请专利5项，其中授权3项。