Highly-loaded metal–organic frameworks (MOFs) based mixed matrix membranes (MMMs) are essential for high-efficiency gas separation. However, the continuous distribution of MOFs across the membrane with intensified interface remains challenging. Herein, a flexible and defects-free MMM with a bi-continuous MOFs pathway is constructed by dopamine (DA)-assisted MOFs growth along nanofibers. Nanofibers are used to upload and distribute ZIF-8, which continues to grow via an epitaxial growth strategy to obtain ZIF-8 fibers, achieving ZIF-8 continuous both in long and short range. DA promotes heterogeneous nucleation and growth of ZIF-8 on fiber surface by chelating with Zn through –OH and –NH groups. DA also ensures excellent interfacial compatibility by hydrogen bonding interaction between amino groups of DA and ether-oxygen groups of PEO. Finally, the highly-loaded MMM is constructed by in-situ photopolymerization of Poly (ethylene glycol) diacrylate) to embrace ZIF-8 fibers tightly. The resultant MMM presents ZIF-8 loading as high as 72.41 vol% with Young’s modulus of 33.42 MPa, and unchanged morphology and separation performances after bending for 180° over 50 times, revealing outstanding mechanical properties. The CO permeability and CO/N selectivity are 280.3 % and 73.0 % higher than the PEO membrane, surpassing the 2019 McKeown upper bound.

中文翻译：

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用于气体分离的具有双连续金属有机框架传输途径的柔性高负载混合基质膜


基于高负载金属有机框架（MOF）的混合基质膜（MMM）对于高效气体分离至关重要。然而，MOF 在膜上连续分布且界面强化仍然具有挑战性。在此，通过多巴胺（DA）辅助的 MOF 沿着纳米纤维生长，构建了具有双连续 MOF 路径的灵活且无缺陷的 MMM。利用纳米纤维上传和分发ZIF-8，通过外延生长策略继续生长，获得ZIF-8光纤，实现ZIF-8长距离和短距离的连续。 DA 通过 -OH 和 -NH 基团与 Zn 螯合，促进 ZIF-8 在纤维表面的异质成核和生长。 DA还通过DA的氨基和PEO的醚氧基之间的氢键相互作用确保了优异的界面相容性。最后，高负载 MMM 通过聚（乙二醇）二丙烯酸酯的原位光聚合来构建，以紧密地包裹 ZIF-8 纤维。所得MMM的ZIF-8负载量高达72.41 vol%，杨氏模量为33.42 MPa，并且在180°弯曲50次后形貌和分离性能没有变化，表现出优异的机械性能。 CO渗透率和CO/N选择性比PEO膜高280.3%和73.0%，超过2019年McKeown上限。