Fabrication of mesoporous carbon/polyimide hybrid membrane by in-situ polymerization and their gas separation performance

Disorder mesoporous carbon (DOMC) and order mesoporous carbon (OMC) were added into polyimide (PI) to fabricate DOMC/PI and OMC/PI hybrid membranes via in-situ polymerization. Many analysis methods, including FTIR, TEM, SEM and XRD were employed to explore the morphology of DOMC or OMC and the effect of their addition on the morphology of the hybrid membranes. The permeation of CO₂ and N₂ was studied using the novel membranes. Due to the porous structure of carbon materials and the interaction between CO₂ molecules and mesoporous carbon, addition of DOMC and OMC does not only increase the free volume of polymeric membrane, but also improve the selective adsorption of membrane for CO₂. The addition of DOMC or OMC enhances both the gas permeabilities of two pure gases (CO₂ and N₂) and the CO₂ selectivity of membranes. With addition content of DOMC and OMC increasing, both the gas permeabilities of two pure gases and the CO₂ selectivity of membranes increase first and then decrease. DOMC has more porous structures and a larger specific surface area compared with OMC, therefor, both CO₂ and N₂ permeability of DOMC/PI hybrid membrane are better than those of OMC/PI hybrid membrane. The two hybrid membranes show the similar CO₂/N₂ selectivity.