Zeolite married to carbon: A new family of membrane materials with excellent gas separation performance

Novel carbon/zeolite nanocomposite membranes with tailorable gas transport properties were fabricated by pyrolysis of polyamic acid/zeolite nanocomposites. The microstructure and gas permeability of these chemically robust materials were altered by varying zeolite loading and final pyrolysis temperature. Characterization of the as-synthesized composite membranes by SEM, XRD, and TEM revealed that the zeolite particles adhered well to the carbon matrix and that the microstructure of the zeolite was not destroyed during pyrolysis. Gas permeation tests using small molecules (H-2, CO2, O-2, N-2) indicated that the composite membranes exhibited outstanding permeability together with high selectivity and followed the molecular sieve mechanism. It is believed that the zeolite embedded in the carbon matrix decreased the gas diffusion resistance and improved the gas permeation rate. The excellent gas transport properties for all test gases make the carbon/zeolite composite an attractive membrane material in gas separation areas.