当前位置: X-MOL 学术Front. Chem. Sci. Eng. › 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.)
Molecular level understanding of CO 2 capture in ionic liquid/polyimide composite membrane
Frontiers of Chemical Science and Engineering ( IF 4.3 ) Pub Date : 2021-01-21 , DOI: 10.1007/s11705-020-2009-7
Linlin You , Yandong Guo , Yanjing He , Feng Huo , Shaojuan Zeng , Chunshan Li , Xiangping Zhang , Xiaochun Zhang

Ionic liquid (IL)/polyimide (PI) composite membranes demonstrate promise for use in CO2 separation applications. However, few studies have focused on the microscopic mechanism of CO2 in these composite systems, which is important information for designing new membranes. In this work, a series of systems of CO2 in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide composited with 4,4-(hexafluoroisopropylidene) diphthalic anhydride (6FDA)-based PI, 6FDA-2,3,5,6-tetramethyl-1,4-phenylene-diamine, at different IL concentrations were investigated by all-atom molecular dynamics simulation. The formation of IL regions in PI was found, and the IL regions gradually became continuous channels with increasing IL concentrations. The analysis of the radial distribution functions and hydrogen bond numbers demonstrated that PI had a stronger interaction with cations than anions. However, the hydrogen bonds among PI chains were destroyed by the addition of IL, which was favorable for transporting CO2. Furthermore, the self-diffusion coefficient and free energy barrier suggested that the diffusion coefficient of CO2 decreased with increasing IL concentrations up to 35 wt-% due to the decrease of the fractional free volume of the composite membrane. However, the CO2 self-diffusion coefficients increased when the IL contents were higher than 35 wt-%, which was attributed to the formation of continuous IL domain that benefitted the transportation of CO2.



中文翻译:

离子液体/聚酰亚胺复合膜中CO 2捕获的分子水平理解

离子液体(IL)/聚酰亚胺(PI)复合膜具有在CO 2分离应用中使用的前景。然而,很少有研究集中在这些复合系统中CO 2的微观机理上,这对于设计新膜是重要的信息。在这项工作中,一系列的CO 2系统与基于4,4-(六氟异亚丙基)二邻苯二甲酸酐(6FDA)的PI,6FDA-2,3,5,6-四甲基-1,4-亚苯基二胺复合的1-丁基-3-甲基咪唑鎓双(三氟甲基磺酰基)酰亚胺通过全原子分子动力学模拟研究了在不同IL浓度下的,。发现在PI中IL区域的形成,并且随着IL浓度的增加,IL区域逐渐变成连续的通道。对径向分布函数和氢键数的分析表明,PI与阴离子的相互作用强于阴离子。然而,通过添加IL破坏了PI链之间的氢键,这对于运输CO 2是有利的。此外,自扩散系数和自由能垒表明CO的扩散系数由于复合膜的自由体积分数的减少,当IL浓度增加至35 wt%时,2降低。然而,当IL含量高于35wt%时,CO 2自扩散系数增加,这归因于形成了连续的IL结构域,这有利于CO 2的运输。

更新日期:2021-01-21
down
wechat
bug