Plasticization- and aging-resistant membranes with venation-like architecture for efficient carbon capture

Plasticization and physical aging due to the undesirable deformation of chain microstructure under high pressure or long-term operation hamper the practical application of polymer membranes. Fixing the polymer chain architecture without sacrificing the internal free volume and thereby the membrane permeability remains a grand challenge. The venation architecture in plant leaf, featured by its stable vein structure with abundant interveinal spaces, offers us an inspiration for designing a highly permeable and stable chain architecture. Here, we construct a venation-like chain architecture in polyphenylene oxide (PPO) membrane by introducing numerous interchain crosslinking bridges using Friedel-Crafts-based hypercrosslinking reaction. These crosslinking bridges rigidify the chains and prevent them from dense packing, inhibiting the microstructural deformation, while simultaneously generating abundant free volume. The resulting membranes display ultrahigh CO₂ permeability of 5130 Barrer (73-fold higher than pristine PPO membrane), along with superior structural stability. Particularly, the plasticization is fully suppressed under high pressure even up to 70 bar and the physical aging-induced loss of CO₂ permeability is reduced remarkably down to as low as 19% after 360 days, transcending most of the state-of-the-art membranes. This venation-like chain architecture opens a new avenue to solving the current permeability-stability dilemma for the implementation of polymer membrane technology.