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Visualizing MOF Mixed Matrix Membranes at the Nanoscale: Towards Structure‐Performance Relationships in CO 2 /CH 4 Separation Over NH 2 ‐MIL‐53(Al)@PI
Author(s) -
Rodenas Tania,
van Dalen Marion,
GarcíaPérez Elena,
SerraCrespo Pablo,
Zornoza Beatriz,
Kapteijn Freek,
Gascon Jorge
Publication year - 2014
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201203462
Subject(s) - membrane , materials science , gas separation , metal organic framework , chemical engineering , nanoscopic scale , polymer , polyimide , solvent , casting , composite material , nanotechnology , organic chemistry , chemistry , biochemistry , engineering , adsorption , layer (electronics)
Mixed matrix membranes (MMMs) composed of metal organic framework (MOF) fillers embedded in a polymeric matrix represent a promising alternative for CO 2 removal from natural gas and biogas. Here, MMMs based on NH 2 ‐MIL‐53(Al) MOF and polyimide are successfully synthesized with MOF loadings up to 25 wt% and different thicknesses. At 308 K and ΔP = 3 bar, the incorporation of the MOF filler enhances CO 2 permeability with respect to membranes based on the neat polymer, while preserving the relatively high separation factor. The rate of solvent evaporation after membrane casting proves key for the final configuration and dispersion of the MOF in the membrane. Fast solvent removal favours the contraction of the MOF structure to its narrow pore framework configuration, resulting in enhanced separation factor and, particularly, CO 2 permeability. The study reveals an excellent filler‐polymer contact, with ca. 0.11% void volume fraction, for membranes based on the amino‐functionalized MOF, even at high filler loadings (25 wt%). By providing precise and quantitative insight into key structural features at the nanoscale range, the approach provides feedback to the membrane casting process and therefore it represents an important advancement towards the rational design of mixed matrix membranes with enhanced structural features and separation performance.