H. Ettouney et U. Majeed, PERMEABILITY FUNCTIONS FOR PURE AND MIXTURE GASES IN SILICONE-RUBBER AND POLYSULFONE MEMBRANES - DEPENDENCE ON PRESSURE AND COMPOSITION, Journal of membrane science, 135(2), 1997, pp. 251-261
Permeability functions are developed for pure gases and mixtures of N-
2, CH4, CO2, and O-2 as a function of driving pressure for polysulfone
and silicone rubber membranes. The gas mixtures used in the measureme
nts include N-2-O-2, CO2-N-2-O-2, and CH4-N-2-CO2. The functions are e
xpressed in a Linear form in terms of species partial pressures. The f
unctions are in good agreement with the measured data. Positive and la
rge weights for the fastest permeating species, CO2, are obtained in t
he permeability functions for all species in polysulfone. The opposite
is obtained for the slower permeating species in the polysulfone perm
eability functions. This result is consistent with the membrane behavi
our, where permeability of faster species is reduced by presence of sl
ower species. The species weights in the silicone rubber permeability
functions are 1-5 orders of magnitudes smaller than the function const
ant. This behaviour is dictated by limited Variations in species perme
ability in silicone rubber.