Effect of plasma treatment on the gas permeability of poly(4-methyl-2-pentyne) membranes

The surface of a poly(4-methyl-2-pentyne) membrane was modified by plasma treatment using CCl4; the permeabilities of O-2, N-2, H-2, CH4 andCO(2)were measured before and after the plasma treatment, and the selectivities of O-2/N-2, H-2/N-2, CO2/N-2, CO2/CH4 and H-2/CH4 were calculated. The selectivities were found to be remarkably improved after plasma treatment while gas permeabilities decreased. The effect of the plasma conditions such as the treatment time and discharge power on the permeabilities of the membranes was investigated in detail. The surface of modified membranes was analyzed by XPS, and the contact angles of water on the membranes were measured by a contact-angle goniometer.