Pore-nested MOFs rigidify microporous polymers for anti-aging CO2 capture membranes

MOFs are nested into intrinsic micropores of membranes by in situ confined growth. • Rigid MOF units interact with polymer chains and suppress polymer relaxation. • MOFs can reconstruct pore architectures and environments for improving selectivity. • Membranes exhibit enhanced aging resistance and separation performance. • After 180-d aging, CO 2 permeability and CO 2 /N 2 selectivity are 3240 Barrer and 47.3. Polymers of intrinsic microporosity (PIMs) with abundant interconnected pathways are promising for fabricating CO 2 capture membranes with exceptional permeability, but their applications are hindered by the issues of physical aging and insufficient selectivity. In this study, we report in situ confined growth of pore-nested metal-organic frameworks (MOFs) within the intrinsic micropores of PIM membranes as scaffolds to reconstruct their pore architectures for addressing the issues of aging and selectivity. Through a simple two-step immersion process for precursor immobilization followed by coordination, the pore-nested MOFs are constructed within the cavities and homogeneously distributed throughout the membranes. As rigid MOF units interact with polymer chains, suppress polymer segmental relaxation, reinforce polymer matrices, and regulate transport pathways, the rigidified membranes exhibit simultaneously enhanced aging resistance and separation performance, with selectivity markedly increasing from 14.6 to 40.3. After natural aging for 180 days, the membranes still retain a CO 2 permeability of 3240 Barrer, 92.3% of the initial value, alongside a CO 2 /N 2 selectivity of 47.3. This study offers a viable route to reshape transport channels via confined synthesis within micropores for designing high-performance and anti-aging separation membranes. Download: Download high-res image (387KB) Download: Download full-size image