Fig. 5: Gas separation performances of mixed gas, anti-plasticization and aging performance.

a 50%/50% CO2/CH4 mixed-gas separation performance at different CO2 upstream partial pressures ranging from 100 to 400 psi. b The upper bound of mixed-gas with 6FDA-TFDB and 6FDA-TFDB-7 CMS membranes. c Physical aging behavior of the 6FDA-TFDB CMS membrane over time. d Physical aging behavior of the 6FDA-TFDB-7 CMS membrane over time.