Streamlined Fabrication of Asymmetric Carbon Molecular Sieve Hollow Fiber Membranes

A microporous polymer, polymer of intrinsic microporosity-1, was utilized as the polymeric precursor to simplify the formation of asymmetric carbon molecular sieve hollow fiber membranes. Unlike other methods, asymmetric carbon membranes were formed directly without cross-linking or other pretreatments. In addition, a facile defect removal treatment was developed that can easily be incorporated into a standard fiber solvent exchange procedure. The resulting asymmetric carbon membranes display extraordinary gas selectivities at or exceeding the upper bound for O2/N2, CO2/CH4, He/N2, and C2H4/C2H6. The simplified, two-step method greatly improves the ease of fabrication of defect-free asymmetric carbon hollow fiber membranes for challenging separations.