Gas separation investigations on polyaniline composite membranes

摘要

Composite homogeneous polyaniline (PANI)/(50/o) polystyrene (PS) membranes cast from benzene solutions and composite laminar mem-branes were studied to determine the permeability coefficients of hydrogen, nitrogen and air, and hence to evaluate the selectivity coefficients in the 02/N2 and H2/N2 systems (Tables 1, 2). The thickness of PANT layer did not affect the permeability coefficients. With PS as carrier substrate, the resulting membranes could not be made less than 5 ~im thick in active layer; they had permeation properties close to those of pure PANT membranes and were me-chanically stable over a pressure range of 0.3—0.5 MPa; such membranes correspond to pure PANT membranes 25 ~im thick; pure PANT membranes 5 ~am thick were entirely unsuitable for permeation studies at the pressures ap-plied. In the homogeneous membranes prepared by emulsion polymeriza-tion, PANT 40—65 1im/PS 35 ~m, the permeability coefficients decreased as the PANT content was increased. The gas molecules permeated along path-ways offering the least resistance to flow, i.e., as in a composite with PANT content equal to zero; the permeation coefficients of such membranes are close to those of polystyrene membranes. Likewise permeability, the selecti-vity coefficients were only slightly affected by active layer thickness.