Bioinspired Graphene Oxide Membranes with Dual Transport Mechanisms for Precise Molecular Separation

The implementation of membrane technology to replace or combine with energy-intensive cryogenic distillation for precise separation of ethylene/ethane mixture proves an extremely important yet highly challenging task. Inspired by the hierarchical structure and facilitated gas transport of biological membranes, a highly selective ethylene/ethane separation membrane is explored through the fixation of a silver ion carrier and the impregnation of ionic liquid within 2D nanochannels of graphene oxide laminate, where plenty of ethylene-permeating in-plane nano-wrinkles and ethylene-facilitated plane-to-plane nanochannels are constructed. By virtue of synergistic effects of molecular sieving and carrier-facilitated transport, an unprecedented combination of high ethylene permeance (72.5 GPU) and superhigh ethylene/ethane selectivity (215) is achieved, out-performing currently reported advanced membranes. Moreover, molecular dynamics simulations verify a favorable membrane nanostructure for fast and selective transport of ethylene molecules. This bioinspired approach with dual transport mechanisms may open novel avenues to the design of high-performance membranes for precise molecular separation.