Microporous Organic Polyimides for CO2 and H2O Capture and Separation from CH4 and N2 Mixtures: Interplay between Porosity and Chemical Function
Microporous Organic Polyimides for CO2 and H2O Capture and Separation from CH4 and N2 Mixtures: Interplay between Porosity and Chemical Function
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DOI：
10.1021/acs.chemmater.6b01949
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发表时间：
2016-08-09
影响因子：
8.6
通讯作者：
Senker, Juergen
中科院分区：
文献类型：
--
作者：
Klumpen, Christoph;Breunig, Marion;Senker, Juergen
多孔聚酰亚胺被认为是用于气体捕获和封存的有前途的材料类别，导致合成大量具有值得注意的吸附性能的单独网络。尽管做出了这些努力，但对小分子吸附和解吸的化学控制的愿景，特别是对于技术相关气体混合物的竞争吸收，仍然几乎没有研究。在这里，我们对五种新型聚酰亚胺网络进行了系统研究，这些网络基于一组具有化学功能的连接体，涵盖从疏水性到亲水性相互作用的整个范围。基于氨基和酸酐连接分子在间甲酚中高温下的缩合反应，成功合成了相应的微孔有机聚酰亚胺（MOPI-I至-V），所有情况下交联度均超过95%。氩气和二氧化碳等温线显示表面积高达 940 m(2)/g，具有超微孔性、约 50% 微孔性和空气下的高热稳定性，分解温度高达 480 摄氏度。不同温度的吸附筛选显示，二氧化碳和水蒸气的显着吸收高达 3.8 mmol/g 和水蒸气高达 19.5 mmol/g，并具有约 0.25 p/p(0) 的光滑浇口开口MOPI-IV。相比之下，MOPI-V 的水蒸气吸收量降至 7 mmol/g。有趣的是，LAST 和 Henry 计算的选择性趋势与摄取行为无关。例如，MOPI-I 和 MOPI-III 的 CO2 选择性分别为 78 和 13，高于 N-2 和 CH4 Henry 选择性，尽管它们的 CO2 吸收量约为 3.0 mmol/g。总的来说，我们将此类材料的吸附特性主要归因于超微孔区域内的空隙尺寸和形状。表面的化学环境似乎对吸收影响不大，而对分离行为影响较大。
Porous polyimides have been considered to be a promising material class for gas capture and sequestration, leading to the synthesis of a substantial number of individual networks with noteworthy sorption properties. In spite of these efforts, the vision of a chemical control of adsorption and desorption of small molecules, in particular, for the competing uptake of technical relevant gas mixtures, is still hardly investigated. Here, we present a systematic study of five new polyimide networks based on a set of linkers with chemical functionalities covering the full range from hydrophobic to hydrophilic interactions. The corresponding microporous organic polyimides (MOPI-I to-V) were synthesized successfully based on a condensation reaction between amino and anhydride linker molecules in m-cresol at high temperatures, resulting in cross-linking degrees beyond 95% in all cases. Argon and carbon dioxide isotherms reveal surface areas up to 940 m(2)/g with ultramicroporosity, about 50% microporosity and high thermal stabilities under air with decomposition temperatures up to 480 degrees C. Sorption screening for variable temperatures revealed remarkable uptakes for carbon dioxide up to 3.8 mmol/g and water vapor up to 19.5 mmol/g combined with a smooth gate opening around 0.25 p/p(0) for MOPI-IV. In contrast, for MOPI-V the water vapor uptake decreases down to 7 mmol/g. Interestingly, the trend of the selectivities calculated by LAST and Henry does not correlate with the uptake behavior. For instance, MOPI-I and MOPI-III exhibit with 78 and 13 the highest CO2 over N-2 and CH4 Henry selectivities, although their CO2 uptake is around 3.0 mmol/g. In total, we attribute the sorption properties for this class of materials mainly to the void size and shape within the ultramicroporous region. The chemical environment of the surfaces seems to have little influence on the uptake and a stronger effect on the separation behavior.