posted on 2021-08-26, 07:03authored byChang
Soo Lee, Eunho Song, Jung Tae Park, Jong Hak Kim
High-performance, thin-film mixed-matrix
membranes (MMMs) on a
porous support have been developed, using zeolitic imidazole framework
(ZIF) decorated graphene oxide (GO) as a filler, dispersed in a poly(vinyl
imidazole)-co-poly(oxyethylene methacrylate) (PVI-POEM)
copolymer matrix. The low gas permeance of the neat GO-filler-based
MMM was significantly improved by routing a CO2-permeable
pathway through the semi-interconnected GO-ZIF nanocages. The good
rubbery adhesion properties of PVI-POEM, together with the chemical
similarity between PVI and the ZIF imidazole linker, induced excellent
polymer/filler interface engineering in the GO-ZIF MMMs. Moreover,
the GO-ZIF nanofillers were fully blanketed by the PVI-POEM copolymer,
to prevent interfacial defects, while in turn an ultrathin, highly
permeable GO-ZIF selective layer was formed. As a result, the GO-ZIF
5% composite MMM achieved a state of the art CO2 permeance
of 995.1 GPU, retaining excellent CO2/N2 and
CO2/CH4 selectivities of 45.9 and 17.5, respectively.
The CO2-philic pathway of GO-ZIF filler and good interaction
bewteen the PVI-POEM and GO-ZIF generate a synergistic effect of CO2 separation, in comparison with a neat PVI-POEM composite
membrane (CO2 permeance 626.4 GPU, CO2/N2 selectivity 36.2).