Facilitated transport mixed matrix membranes incorporated with amine functionalized MCM-41 for enhanced gas separation properties

Facilitated transport mixed matrix membranes (FT-MMMs) were fabricated by incorporating polyethylenimine functionalized ordered mesoporous silica (PEI-MCM-41) into poly(ether-block-amide) (Pebax ® MH 1657). The polyethylenimine both in the pore channels and on the surface of MCM-41 rendered abundant amine carriers to facilitate the transport of CO 2 through reversible reaction and simultaneously improved the filler–polymer interface compatibility. The membranes were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile test, dynamic mechanical analysis (DMA), and X-ray diffraction (XRD). The results indicated that incorporation of PEI-MCM-41 generated stronger interfacial interactions and resulted in higher polymer chain rigidification at the filler–polymer interface compared with unmodified MCM-41. The as-prepared FT-MMMs showed increased gas permeability and selectivity, and the highest ideal selectivities for CO 2 /CH 4 and CO 2 /N 2 were 41 and 102 (at a CO 2 permeability of 1521   Barrer), respectively. Compared to the membranes doped with pristine MCM-41, the permeability, the ideal CO 2 /CH 4 selectivity and the ideal CO 2 /N 2 selectivity of the PEI-MCM-41-doped membranes were increased by 102.3%, 115.8% and 96.1%, respectively, at 20   wt% filler loading and surpassed the 2008 Robeson upper bound line.