H. Kumazawa et al., GAS-TRANSPORT THROUGH HOMOGENEOUS AND ASYMMETRIC POLYETHERSULFONE MEMBRANES, Journal of polymer science. Part B, Polymer physics, 31(7), 1993, pp. 881-886
Both homogeneous and asymmetric polyethersulfone (PES) membranes were
prepared by solvent casting. The sorption and permeation behavior of C
O2, O2, and N2 Using these two kinds of cast PES membranes and commerc
ially available homogeneous PES film was investigated to extract the p
ressure dependence of gas permeability and the permselectivity for CO2
relative to N2, and to confirm the validity of the working assumption
that a skin layer in an asymmetric membrane can be essentially replac
ed by a thick homogeneous dense membrane. The pressure dependence of t
he mean permeability coefficient to CO2 in homogeneous membranes obeys
the dual-mode mobility model. The ideal separation factor for CO2 rel
ative to N2 at an upstream pressure of 0.5 MPa attains ca. 40, while t
he permeability to CO2 is about 2.7 Barrer at the same upstream pressu
re. The same separation factor in asymmetric membranes amounts to 35.
The diffusion behavior for the skin layer in an asymmetric membrane wi
th a thin skin layer can be simulated approximately by that in a homog
eneous dense membrane.