Effect of ultraviolet light irradiation on gas permeability in polyimide membranes. II. Irradiation of membranes with high-pressure mercury lamp

✍ Scribed by Shigetoshi Matsui; Tsutomu Nakagawa

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 270 KB
• Volume: 67
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980103)67:1<49::aid-app6>3.0.co;2-o

✦ Synopsis

A photocrosslinkable polyimide membrane was prepared and investigated with regard to the effect of ultraviolet light irradiation (UV-irradiation) using a highpressure mercury lamp on their gas permeabilities and permselectivities. Permeability and diffusion coefficients for O 2 , N 2 , H 2 , and CO 2 were determined using the vacuumpressure and time-lag methods. Sorption properties for carbon dioxide were determined to evaluate the changes in the free volume in the membranes by the irradiation. The apparent gas permeabilities decreased and permselectivity, particularly for H 2 over N 2 , increased with increasing UV-irradiation time without a significant decrease in the flux of H 2 . They depended on the membrane thickness, suggesting asymmetrical changes in the membrane due to UV-irradiation.