Effect of incorporated hybrid MIL-53(Al) and MWCNT into PES membrane for CO2/CH4 and CO2/N2 separation

Abstract

In this study, MIL-53(Al) particles and –COOH functionalized multi-walled carbon nanotube (MWCNT) were combined as the dispersed phase to synthesize a hybrid structure, MIL-53(Al)@MWCNT. In the next step, MIL-53(Al)@MWCNT was embedded in a polyethersulfone (PES) polymer matrix to prepare PES/MIL-53(Al)@MWCNT mixed matrix membrane (MMM) for CO2/CH4 and CO2/N2 separation. Different techniques, including SEM, XRD, FT-IR, BET, and TGA, were used to confirm the successful synthesis of MMMs. Adding MWCNTs prevented MIL-53(Al) aggregation in the polymer matrix and enhanced membrane mechanical properties and gas separation efficiency. Furthermore, the correlation between MWCNT and MIL-53(Al) created a rapid transfer channel for CO2 molecules. According to the results, the MMM containing 5 wt% of MIL-53(Al)@MWCNT showed high CO2/N2 and CO2/CH4 ideal selectivity of 87 and 58.6 along with a desired permeability of 183 barrer than the pure PES membrane indicating a favorable CO2 separation efficiency. Moreover, performance shifted towards the corresponding upper bounds.