High-productive, nanostructured polyaniline membranes for gas separation

A novel method to make reproducible defect free self-supported polyaniline films with thicknesses between 2 and 6 µm, and polyaniline nanomembranes with a selective layer thickness as thin as 300 nm supported on a porous poly-vinylidene difluoride (PVDF) structure is developed. For dense polyaniline membranes, ideal separation factors for all gas pairs tested were independent of the membrane thickness. The selectivities, aA/ B (ideal), for the gas pairs H2/N2 (348.4), H2/O2 (69.5), H2/CO2 (8.6), CO2/O2 (8.1), CO2/N2 (40.4) and O2/N2 (5.0), achieved for self-supported undoped polyaniline films are considerably higher than those obtained by other researchers. Ideal separation factors for polyaniline nanomembranes were similar to those obtained for selfsupported polyaniline films. Gas transport rates for various gases, observed for the dense polyaniline nanofilms supported on polyvinylidene difluoride were of the order of 105 times higher than those reported for self-supported polyaniline membranes.