Abstract
Preparation methods are presented of thin dual layer membranes (DLM's) and mixed matrix membranes (MMM's) based on nanosheets of the Cu-BDC metal-organic framework (MOF, lateral size range 1–5 µm, thickness 15 nm) and commercially available poly(ethylene oxide)–poly(butylene terephthalate) (PEO–PBT) copolymer (Polyactive™) and their performances are compared in CO2/N2 separation. The MMMs and DLMs represent two extremes, on the one hand with well-mixed components and on the other hand completely segregated layers. Compared to the free-standing membranes, the thin PAN- and zirconia-alumina-supported MMMs showed significant enhancement in both permeance and selectivity. The support properties affect the obtained selective layer thickness and its resistance impacts the CO2/N2 selectivity. The permeance of thin DLM's is among the highest reported literature data of MOF based thin MMMs, but have a modest selectivity. Addition of the nanosheets in the thin MMMs improves the CO2/N2 selectivity of the already selective polymer further to 77. The nanosheets in the thin MMMs make a gutter layer on the PAN support superfluous. The small pore support ZrO2-alumina does not need a gutter layer. XRD analysis reveals that the spatial distribution of MOF nanosheets and polymer chains packing were responsible for differences in the permeation performance of the free-standing, thin dual layer and mixed matrix membranes.
Original language | English |
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Pages (from-to) | 226-235 |
Journal | Journal of Membrane Science |
Volume | 570-571 |
DOIs | |
Publication status | Published - 2019 |
Keywords
- CO/N
- Cu-BDC
- Dual layer
- Gas separation
- Mixed matrix membranes
- MOF nanosheets
- Polyactive™