Pure- and mixed-gas CO2/CH4 separation properties of PIM-1 and an amidoxime-functionalized PIM-1
Pure- and mixed-gas CO2/CH4 separation properties of PIM-1 and an amidoxime-functionalized PIM-1
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DOI：
10.1016/j.memsci.2014.01.055
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发表时间：
2014-05
影响因子：
9.5
通讯作者：
Raja Swaidan;B. Ghanem;E. Litwiller;I. Pinnau
中科院分区：
文献类型：
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作者：
Raja Swaidan;B. Ghanem;E. Litwiller;I. Pinnau
具有固有微孔性的原型溶液可加工聚合物PIM-1及其衍生物提供了渗透性和选择性的组合，使其成为基于膜的气体分离的潜在候选材料。对于经济的天然气脱硫PIM的设计和评估来说，最重要的是在实际的混合气体条件下具有高且稳定的CO2/CH 4选择性。在这里，酰胺肟官能化的PIM-1（AO-PIM-1）的制备和检查的基本结构/性能的关系。物理吸附等温线的定性NLDFT孔径分布分析（N2在-196 ° C; CO2在0 ° C）揭示了一个收紧的微观结构，表明尺寸筛分超微孔（<7 μ m）。AO-PIM-1的αD（CO2/CH 4）比PIM-1增加了三倍，超过了2008年的上限，P（CO2）=1153 Barrer，理想α（CO2/CH 4）=34。在50：50的CO2：CH 4混合气体进料下，AO-PIM-1的选择性损失小于PIM-1，在20 bar压力范围内混合气体的α（CO2/CH 4）保持在21左右。相反，PIM-1经受了高达60%的增加，在混合气体的CH 4渗透性超过纯气体值，同时在20巴的选择性只有~8。AO-PIM-1中普遍存在的分子间氢键网络主要产生硬化的微观结构，可减轻CO2诱导的基质膨胀，减少有害的混合气体CH 4共渗透。
The prototypical solution-processable polymer of intrinsic microporosity, PIM-1, and derivatives thereof offer combinations of permeability and selectivity that make them potential candidate materials for membrane-based gas separations. Paramount to the design and evaluation of PIMs for economical natural gas sweetening is a high and stable CO2/CH4selectivity under realistic, mixed-gas conditions. Here, amidoxime-functionalized PIM-1 (AO-PIM-1) was prepared and examined for fundamental structure/property relationships. Qualitative NLDFT pore-size distribution analyses of physisorption isotherms (N2at -196oC; CO2at 0oC) reveal a tightened microstructure indicating size-sieving ultra-microporosity (<7 Å). AO-PIM-1 demonstrated a three-fold increase inαD(CO2/CH4) over PIM-1, surpassing the 2008 upper bound with P(CO2)=1153 Barrer and idealα(CO2/CH4)=34. Under a 50:50 CO2:CH4mixed-gas feed, AO-PIM-1 showed less selectivity loss than PIM-1, maintaining a mixed-gasα(CO2/CH4) ~21 across a 20 bar pressure range. Conversely, PIM-1 endured up to 60% increases in mixed-gas CH4permeability over pure-gas values concurrent with a selectivity of only ~8 at 20 bar. A pervasive intermolecular hydrogen bonding network in AO-PIM-1 predominantly yields a rigidified microstructure that mitigates CO2-induced matrix dilations, reducing detrimental mixed-gas CH4copermeation.