Fig. 4

CO2/N2 mixture separation performance of GOP membranes and comparison with membranes reported in the literature. a Influence of temperature on GOP membrane performance for mixed gas (CO2: N2 = 15%: 85%, vol%) separation under wet condition. It is noted that some error bars of CO2 permeance were smaller than the cubic symbol, and thus they are not shown in the figure. b Performance comparison of GOP membranes with polymeric membranes (black line) reported in 2008 upper bound11 (modified upper bond (in GPU), thickness of polymer membranes is assumed to be 100 nm) and some representative recent membranes6,7,8, 19, 21,22,23, 41, 42. Squares denote the GO-based membranes; triangles denote the polymer-based membranes. (1) GO19. (2) GO-Pebax22. (3) GO-PEI23. (4) GO-Borate21. (5) Pebax-PEG-POSS6. (6) PEI-Silica-Pebax7. (7) PDMS41. (8) PVAm42. (9) PEG-based8. (10) GO on single feed tests, this work. (11) to (14) GOP at 24, 40, 60, 80 °C, respectively, wet mixed feed, this work