Positively Charged Polymer‐Brush MOFs for Large‐Area, Pressure‐Resistant Gas Separation Membranes

Abstract

ABSTRACT Scalable fabrication of high‐performance gas separation membranes remains a major challenge for energy‐efficient gas purification. Industrial translation of pressure‐resistant mixed matrix membranes (MMMs) is largely impeded by the dispersion instability of nanofillers under rapid, non‐equilibrium manufacturing conditions, which leads to uncontrollable aggregation and interfacial defects during processing. Here, we present a universal “pre‐occupation and post‐activation” strategy to construct positively charged polymer‐brush metal–organic frameworks (MOFs). This approach endows the fillers with a dual‐stabilization mechanism: electro‐steric effects ensure static dispersion stability, while a hydrogen‐bonding‐driven interfacial interlocking mechanism maintains stability during dynamic processing. Together, these mechanisms synergistically facilitate the seamless integration of nanofillers within ultrathin selective layers. This design allows roll‐to‐roll production of 1 m‐wide, pressure‐resistant mixed matrix composite membranes (MMCMs) with tunable CO 2 separation performance. The resulting MMCMs deliver outstanding CO 2 /CH 4 and CO 2 /N 2 separation under industrially relevant pressures, reducing the required membrane area by more than an order of magnitude compared with laboratory‐scale membranes. A spiral‐wound module with an effective area of 0.4–2 m 2 further validates the scalability and operational robustness. This work overcomes a long‐standing barrier in MMM processing, marking a significant step toward industrial implementation of MOF‐based, energy‐efficient gas separation technologies.