Fabrication of asymmetric polyethersulfone membranes for separation of carbon dioxide from methane using polyetherimide as polymeric additive

- The gas permeance and CO2/CH4 selectivity of PES membranes were changed by PEI.
- CO2 induced plasticization and gas sorption of PES were decreased by PEI.
- PEI increases the fractional free volume of PES.
- PEI decreases the porosity, thermal resistance and Tg of PES membrane.
- PEI decreases the activation energy of the permeation for CO2 and CH4.