▎ 摘　　要

The effect of graphene oxide (GO) nanosheets on the CO2/CH4 separation performance of a rubbery (poly(dimethylsiloxane), PDMS) as well as a glassy (polyetherimide, PEI) polymer is studied. Interfacial interactions between the nanosheets and both polymers are revealed by FTIR and SEM. The results of gas permeation through the membranes demonstrate that GO nanosheets enhance CO2/CH4 diffusivityselectivity of PEI and CO2/CH4 solubility-selectivities of the PEI and PDMS polymers, while diminish CO2/CH4 diffusivity-selectivity of PDMS. Furthermore, the possibility of overcoming the common tradeoff between CO2 permeability and CO2/CH4 selectivity of rubbery and glassy polymers by incorporating very low amounts of graphene oxide nanosheets is addressed. In other words, at 0.25 wt % GO loading, the PEI membrane shows simultaneous enhancement of CO2 permeability (16%) and CO2/CH4 selectivity (59%). Also, for the PDMS membrane simultaneous enhancement of CO2 permeability (29%) and CO2/CH4 selectivity (112%) is occurred at 0.5 wt % GO loading. Finally, the capability of the well known Nielsen model to predict the gas permeability behavior of the nanocomposites is investigated.