Defect-Free Calixarene-PIM-1 membranes featuring microcrystalline colloidal Networks for enhanced carbon capture

To achieve the vision of carbon neutrality, carbon capture, utilization, and storage (CCUS) technologies have attracted significant attention. Among them, membrane separation technology, as one of the leading front-end approaches for carbon capture, plays a vital role in enabling zero carbon emissions. In recent years, polymers of intrinsic microporosity (PIMs) membranes have emerged as prominent candidates for advanced separation technologies, owing to their unparalleled gas transport rates. However, their development has been hindered by drawbacks such as low selectivity and poor aging resistance. In this work, C-Methylcalix [4] resorcinarene (C[4]) was anchored within a host polymer matrix via in situ polymerization. The hydroxyl-rich C[4] not only increased the degree of distortion of the polymer chain and enlarged the pore size of the membranes, but also enhanced the affinity between the polymer and CO₂. The separation performance of 5 %C[4] could surpass the 2008 upper bound, with a CO₂/N₂ selectivity increase of 61.3 %. Furthermore, The incorporation of C[4] induced the development of ordered microcrystalline colloidal network within the polymer matrix, imparting enhanced structural rigidity to the molecular backbone. This modification significantly improved the membrane’s resistance to physical aging, as evidenced by a mere 21.3 % reduction in CO₂ permeability for the 5 %C[4] after 6 months, in stark contrast to the 67.4 % decline observed in pristine PIM-1. These results underscore the material’s robustness and highlight its viability for industrial gas separation applications requiring long-term operational stability.