Abstract Membrane-based separations are of energy-efficient and environmentally benign attributes for biogas energy developments. Membranes from polymers of intrinsic microporosity (PIMs) often suffer from low selectivity. In this study, remarkable enhancements in CO2/CH4 selectivity of PIM-1 membranes are achieved by incorporating nano-sized ZIF-67 (ZIF-S) filler with a larger specific surface area and a better compatibility, thereby fortifying the interactions with PIM-1 matrix and effectively alleviating nonselective interfacial voids. For the resulting PIM-1/ZIF-S membranes, a maximum CO2/CH4 selectivity of 21.1 was acquired with 15 wt% loading of ZIF-S, an increase of 69.40% compared with the pristine PIM-1 membrane, along with an associated CO2 permeability above 2800 Barrer. To elucidate gas transport behaviors within membranes, a modified Maxwell model is developed and the calculation results match well with the experimental data. The strategy of incorporating framework nanofillers into membranes may find promising applications in enhancing the selectivity of highly permeable polymer membranes.

中文翻译：

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结合纳米尺寸的 ZIF-67 以提高用于沼气升级的固有微孔膜聚合物的选择性

摘要 基于膜的分离对于沼气能源开发具有节能和环境友好的特性。由固有微孔 (PIM) 聚合物制成的膜通常具有低选择性。在这项研究中，通过加入具有更大比表面积和更好相容性的纳米级 ZIF-67 (ZIF-S) 填料，显着提高了 PIM-1 膜的 CO2/CH4 选择性，从而加强了与 PIM-1 的相互作用。 1 基质，有效缓解非选择性界面空隙。对于所得的 PIM-1/ZIF-S 膜，在 ZIF-S 负载量为 15 wt% 的情况下获得了 21.1 的最大 CO2/CH4 选择性，与原始 PIM-1 膜相比增加了 69.40%，以及相关联的CO2 渗透率高于 2800 Barrer。为了阐明膜内的气体传输行为，建立了修正的麦克斯韦模型，计算结果与实验数据吻合良好。将骨架纳米填料掺入膜中的策略可能会在提高高渗透性聚合物膜的选择性方面找到有前景的应用。