3D Interwoven COFs nano-network: Synergistic integration of CO2-philic and low-resistance transport through continuous electrospun-based pathways

The performance upper bound of mixed-matrix membranes (MMMs) stems from discontinuous filler dispersion and impaired transfer kinetics. Herein, we propose to construct 3D interpenetrating covalent organic frameworks (COFs) architecture synergizing physisorption and rapid gas molecular transport to enhance CO 2 separation. Electrospun polyacrylonitrile (PAN) nanofibers induce the heterogeneous epitaxial growth of functionalized TpPa-1/TpPa-SO 3 H to create a bi-continuous transport highway with (i) 3D-interconnected micropores (∼1.8 nm) for low-resistance diffusion and physical adsorption and (ii) multi-channel chemisorption via CO 2 -philic groups (such as amino, hydroxyl, and sulfonic acid). Resultantly, the CO 2 permeability and CO 2 /N 2 selectivity of the prepared PEO/HPAN@TpPa-SO 3 H 3 MMM were improved by 32.02 % and 62.18 %, respectively, compared with the direct-blending PEO/TpPa–SO 3 H–14.90 wt% membrane. The electrospun-based nano-network assembly establishes a material paradigm for overcoming the physico-chemical adsorption-diffusion trade-off in gas separation membranes.