ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Pressure-normalized gas fluxes for defect-free integral-asymmetric membranes prepared according to a dry/wet phase inversion process were measured as a function of temperature and pressure and compared to measurements on thick isotropic films. Asymmetric membranes were prepared from polysulfone, polycarbonate, and poly(ester carbonate). The activation energies of permeation for O2 and N2 in the range of 25-55°C were higher for the asymmetric polysulfone membranes than for a thick isotropic film. O2/N2 selectivities of the asymmetric membranes are higher than those for isotropic films. The asymmetric membranes did not show the typical dualmode behavior for the CO2 flux as a function of pressure as determined for thick films. Differences in the free volume and its distribution in the ultrathin skin layer of the asymmetric membranes compared to isotropic films may be responsible for these results. © 1993 John Wiley & Sons, Inc.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1993.070481210
