Enhanced gas permeability of cellulose acetate membranes under microwave irradiation

In this study, the permeability coefficients of various gases for a cellulose acetate (CA) and polystyrene (PS) membrane were measured under microwave irradiation by using a handmade apparatus, which can irradiate a microwave (2450 MHz). Permeability in the PS membrane that have no polar functional groups was not affected by irradiating microwave, while permeability coefficients for various gases in the CA membrane that have polar functional groups were more than these without microwave irradiation. Further, the degree of increment in permeability coefficients with microwave depended on kinds of permeation gas. The increment of Kr permeability under microwave irradiation was most remarkable. It could be expected that microwave accelerate the mobility of polar functional groups in polymeric membranes, and then, gas permeability improve due to an extension of diffusion path in membranes. (c) 2005 Elsevier B.V. All rights reserved.