A BPDA-pp'ODA polyimide film was formed on the outer surface of a porous alumina support tube (outside diameter = 2.4 mm), and it was carbonized at an optimized temperature, 700°C. The membrane obtained showed a permeance of 3 x 10-9 mol·m-2·s-1·Pa-1 for O2 and 2 x 10-8 mol·m-2·s-1·Pa-1 for CO2 and a permselectivity of 10 for O2/N2 and 47 for CO2/N2 at 35°C. The membrane was then modified with carbon deposits formed by pyrolysis of propylene at 650°C. The permselectivities for O2/N2 and CO2/N2 at 35°C were increased to 14 and 73, respectively. Coexisting water vapor decreased permeances of O2 and N2 but did not change the O2/N2 permselectivity.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation