Gas sorption and transport of ozone-treated polysulfone

Gas sorption and transport properties of ozone-treated polysulfone (PSF) were investigated. Ozone treatment of PSF was made by the exposure of PSF to ozone-containing oxygen for certain hours. Gas sorption isotherms for PSF were made for N2, O2, CH4 and CO2, and sorption data were analyzed by the dual-mode sorption model. Overall sorption for each gas except CO2 decreased after ozone treatment of PSF. Dual sorption parameters kD and b decreased and CH′ increased for all the gases after ozone treatment. Diffusion coefficients were calculated by the equation P=DS. The diffusion coefficient of each gas decreased after ozone treatment. The increase in the ideal selectivity of ozone-treated PSF, α(O2/N2) was more affected by the difference in diffusion coefficients between ozone-treated PSF and untreated PSF than by the difference in solubility coefficients. However, α(CO2/CH4) was affected by differences in solubility coefficients as well as diffusion coefficients.