Surface modification of polyimide and polysulfone membranes by ion beam for gas separation

✍ Scribed by Jongok Won; Myung Ho Kim; Yong Soo Kang; Hyun Chae Park; Un Young Kim; Sung Chang Choi; Seok Keun Koh

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 136 KB
• Volume: 75
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000321)75:12<1554::aid-app14>3.0.co;2-r

✦ Synopsis

The surface carbonization of polyimide (PI) and polysulfone (PSf) by ion beam has been performed to adapt the carbon molecular sieve properties on the skin of the polymeric membranes without the deformation of the membrane structure. In order to control the structure of membrane skin and to improve gas transport properties, the irradiation conditions, such as the dosage and the source of ion beams, have been varied. The ideal separation factor of CO 2 over N 2 through the surface-modified PI and PSf membranes increased threefold compared to those of the untreated, pristine membranes, whereas the permeability decreased with almost two orders of magnitude. This appears to be due to the fact that the structure of membrane skin has been changed to a barrier layer. The formation of barrier layer was confirmed by comparing the calculated values of a simple resistance model with the experimental results, and the estimated permeability of this barrier was 10 Ϫ4 barrer. It was concluded that ion beam irradiation could provide a useful tool for improving selectivity for gas separation membranes.