The influence of the functional group density on gas flow and selectivity: Nanoscale interactions in alkyl-functionalized mesoporous membranes
Veröffentlichungsdatum
2017-01-01
Zusammenfassung
Mesoporous inorganic structures with mean pore diameters of 26 nm are prepared by extrusion based on a yttria stabilized zirconia nanopowder. The sintered capillary membranes serve as model structures to investigate the influence of an alkyl-chain (C16) surface functionalization on the gas diffusion kinetics of argon (Ar), nitrogen (N2) and carbon dioxide (CO2) in mesopores. The density of the C16 alkyl-chains immobilized on the membrane surface has an effect on both, gas flow as well as gas selectivity. For low functional group densities (<4 groups nm−2), the gas flow is reduced without having an effect on the selectivity. In contrast, for high alkyl-chain densities (>4 groups nm−2) the mean distance between the C16-chains is reduced to the order of magnitude of the gas molecules leading to a reduction in gas flow and a significant change of the gas selectivity. The selectivity is found to be influenced depending on the molecular diameter of the gas species, being more evident for CO2 compared to Ar and N2, suggesting a separation mechanism more comparable to molecular sieving than to surface diffusion.
Schlagwörter
Mesoporous ceramic membrane
;
Surface functionalization
;
Gas permeation
;
Knudsen diffusion
;
Mimenima
Verlag
Elsevier
Institution
Dokumenttyp
Artikel/Aufsatz
Zeitschrift/Sammelwerk
Band
237
Startseite
38
Endseite
48
Seitenzahl
11
Zweitveröffentlichung
Ja
Dokumentversion
Postprint
Sprache
Englisch
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Name
B. Besser, S. Malik, M. Baune, S. Kroll, J. Thöming, K. Rezwan, The influence of the functional group density on gas flow_2017_accepted version.pdf
Size
3.09 MB
Format
Adobe PDF
Checksum
(MD5):4ceb3d4e15762f8a1adba7844cd8a8a0