Mechanism of gas transport in plasma treated glassy polymer films

The effect of oxygen- and Ar-plasma treatment on glassy polysulfone and polyimide films upon the gas diffusion process was investigated in the permeation of CO2 and H2. The plasma treatment apparently induced a reduction of only the diffusivity of Henry's law population, while the diffusion coefficient of the Langmuir population was not altered by plasma treatment. The oxygen- and Ar-plasma treatment on polysulfone films is favorable for permselectivity of H2 relative to CO2. Such a surface modification of polyimide films appears to be ineffective for improvement of permselectivity of H2.