PolyMOF nanoparticles constructed from intrinsically microporous polymer ligand towards scalable composite membranes for CO2 separation

Integrating different modification strategies into a single step to achieve the desired properties of metal–organic frameworks (MOFs) has been very synthetically challenging, especially in developing advanced MOF/polymer mixed matrix membranes (MMMs). Herein, we report a polymer–MOF (polyMOF) system constructed from a carboxylated polymer with intrinsic microporosity (cPIM-1) ligand. This intrinsically microporous ligand could coordinate with metals, leading to ~100 nm-sized polyMOF nanoparticles. Compared to control MOFs, these polyMOFs exhibit enhanced ultramicroporosity for efficient molecular sieving, and they have better dispersion properties in casting solutions to prepare MMMs. Ultimately, integrating coordination chemistries through the cPIM-1 and polymer-based functionality into porous materials results in polyMOF/PIM-1 MMMs that display excellent CO 2 separation performance (surpassing the CO 2 /N 2 and CO 2 /CH 4 upper bounds). In addition to exploring the physicochemical and transport properties of this polyMOF system, scalability has been demonstrated by converting the developed MMM material into large-area (400 cm 2 ) thin-film nanocomposite (TFN) membranes. Microporous polymer ligand provides particle size reduction, enhanced ultramicroporosity (3–4 Å), and better colloidal stability in the polymer–metal–organic framework (polyMOF) system. This leads to defect-free and scalable composite membranes for efficient CO2 separation.