Ultra‐thin skin carbon hollow fiber membranes for sustainable molecular separations

Significance A transformative platform is reported to derive ultra‐thin carbon molecular sieve (CMS) hollow fiber membranes from dual‐layer precursor hollow fibers with independently tuned skin layer and substrate properties. These ultra‐thin CMS hollow fiber membranes show attractive CO2/CH4 separation factors and excellent CO2 permeances up to ~1,400% higher than state‐of‐the‐art asymmetric CMS hollow fiber membranes. They provide a unique combination of permeance and selectivity competitive with zeolite membranes, but with much higher membrane packing density and potentially much lower costs.