当前位置: X-MOL 学术J. Phys. Chem. A › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Spectroscopic Study on the Intermediates and Reaction Rates in the Oxidation of Levitated Droplets of Energetic Ionic Liquids by Nitrogen Dioxide
The Journal of Physical Chemistry A ( IF 2.9 ) Pub Date : 2018-08-03 00:00:00 , DOI: 10.1021/acs.jpca.8b05244
Stephen J. Brotton 1 , Michael Lucas 1 , Tonya N. Jensen 2 , Scott L. Anderson 2 , Ralf I. Kaiser 1
Affiliation  

To optimize the performance of hypergolic, ionic-liquid-based fuels, it is critical to understand the fundamental reaction mechanisms of ionic liquids (ILs) with the oxidizers. We consequently explored the reactions between a single levitated droplet of 1-butyl-3-methylimidazolium dicyanamide ([BMIM][DCA]), with and without hydrogen-capped boron nanoparticles, and the oxidizer nitrogen dioxide (NO2). The apparatus consists of an ultrasonic levitator enclosed within a pressure-compatible process chamber interfaced to complementary Fourier-transform infrared (FTIR), Raman, and ultraviolet–visible spectroscopic probes. First, the vibrational modes for the Raman and FTIR spectra of unreacted [BMIM][DCA] are assigned. We subsequently investigated the new structure in the infrared and Raman spectra produced by the reaction of the IL with the oxidizer. The newly produced peaks are consistent with the formation of the functional groups of organic nitro-compounds including the organic nitrites (RONO), nitroamines (RR′NNO2), aromatic nitro-compounds (ArNO2), and carbonitrates (RR′C═NO2), which suggests that the nitrogen or oxygen atom of the nitrogen dioxide reactant bonds to a carbon or nitrogen atom of [BMIM][DCA]. Comparison of the rate constants for the oxidation of pure and boron-doped [BMIM][DCA] at 300 K shows that the boron-doping reduces the reaction rate by a factor of approximately 2. These results are compared to the oxidation processes of 1-methyl-4-amino-1,2,4-triazolium dicyanamide ([MAT][DCA]) with nitrogen dioxide (NO2) studied previously in our laboratory revealing that [BMIM][DCA] oxidizes faster than [MAT][DCA] by a factor of about 20. The present measurements are the first studies on the reaction rates for the oxidation of levitated ionic-liquid droplets.

中文翻译:

二氧化氮氧化高能离子液体悬浮液滴中中间体和反应速率的光谱研究

为了优化基于离子液体的高分子量燃料的性能,了解离子液体(ILs)与氧化剂的基本反应机理至关重要。因此,我们研究了带有和不带有氢封端硼纳米粒子的1-丁基-3-甲基咪唑鎓双氰胺([BMIM] [DCA])悬浮液滴与氧化剂二氧化氮(NO 2)之间的反应。)。该设备由封闭在压力兼容的处理室内的超声悬浮器组成,该处理室与互补的傅立叶变换红外(FTIR),拉曼和紫外可见光谱探针对接。首先,分配未反应的[BMIM] [DCA]的拉曼光谱和FTIR光谱的振动模式。随后,我们研究了由IL与氧化剂反应产生的红外和拉曼光谱中的新结构。新产生的峰与有机硝基化合物(包括有机亚硝酸盐(RONO),硝胺(RR'NNO 2),芳香族硝基化合物(ArNO 2)和碳酸盐(RR'C═)的官能团的形成相一致。NO 2 -),这表明二氧​​化氮反应物的氮或氧原子与[BMIM] [DCA]的碳或氮原子键合。比较纯的和掺杂的[BMIM] [DCA]在300 K时的氧化速率常数,结果表明掺硼将反应速率降低了约2倍。将这些结果与1的氧化过程进行了比较。先前在我们实验室中研究过的带有二氧化氮(NO 2)的-甲基-4-氨基-1,2,4-三唑鎓双氰胺([MAT] [DCA])显示[BMIM] [DCA]的氧化速度比[MAT] [ DCA]的系数约为20。目前的测量是对悬浮离子液体液滴氧化反应速率的首次研究。
更新日期:2018-08-03
down
wechat
bug