GAS-TRANSPORT PROPERTIES OF POLYANILINE MEMBRANES

The transport properties of He, H-2, CO2, O-2, N-2, and CH4 gases in s olvent cast, HCl doped, and undoped polyaniline (PANi) membranes were determined. Measurements were carried out at 40 psi pressure from 19 d egrees C to 60 degrees C. An excellent correlation was found between t he diffusion coefficients and the molecular diameters of gases. The so lubility coefficients of gases were found to correlate with their boil ing points or critical temperatures. The separation factors for CO2/N- 2 and CO2/CH4 are dominated by the high solubility of CO2. These corre lations enable us to predict the permeability, diffusion, and solubili ty coefficients of other gases. After the doping-undoping process, the fluxes of gases with kinetic diameters smaller than 3.5 Angstrom incr eased but those of larger gases decreased. This results in a higher se paration factor for a gas pair involving a small gas molecule and a la rger one. (C) 1996 John Wiley & Sons, Inc.