Investigation of gas permeability in carbon nanotube (CNT)− polymer matrix membranes via modifying CNTs with functional groups/metals and controlling modification location

Ge, Lei and Zhu, Zhonghua and Li, Feng and Liu, Shaomin and Wang, Li and Tang, Xuegang and Rudolph, Victor (2011) Investigation of gas permeability in carbon nanotube (CNT)− polymer matrix membranes via modifying CNTs with functional groups/metals and controlling modification location. The Journal of Physical Chemistry C, 115 (14). pp. 6661-6670. ISSN 1932-7447

Abstract

Metal- or functional group-modified multiwalled carbon nanotubes (CNTs) were embedded into the poly(ether sulfone) (PES) polymer matrix to study the gas permeability of the nanocomposite membranes. Carboxyl-functionalized CNTs and Ru (Fe) metal-modified CNTs were prepared via acid oxidation and wet impregnation methods, respectively. The derived nanocomposite membranes show similar crystalline structure and CNT dispersion as well as improvement in gas permeation fluxes at low CNT concentration (<5 wt %). However, the CO 2/N2 selectivity varies with different modification components. Compared with pure polymer membranes, those containing Ru-modified CNTs show higher gas selectivity, while Fe-modified CNT membranes show lower selectivity, and carboxyl CNT composite membranes are similar to pure PES membrane. By controlling Ru modification into CNT channels, poor gas selectivity of the corresponding membranes is observed. These results, combined with the results of density functional theory calculations, indicate that different gas adsorption behaviors are introduced via modification by metals or carboxyl functional groups and further influence the gas permeability. Based on both experimental and theoretical results, gas diffusion appears to pass through the interface between polymer chains and carbon nanotubes, rather than the CNT channels, in this nanocomposite system. Thereby, tailoring modification on the external surface of carbon nanotubes can be more effective for improving gas separation performance of CNT-based nanocomposite membranes.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 25 May 2017 05:15
Last Modified: 25 May 2017 05:15
Uncontrolled Keywords: adsorption behavior; CNT dispersion; crystalline structure; density functional theory calculations; external surfaces; functionalized; gas diffusion; gas permeation; gas selectivity; gas separations; nanocomposite membranes; nanocomposite systems; poly(ether sulfone); polymer chains; pure polymers; theoretical result; wet impregnation method; carbon nanotubes; composite membranes; density functional theory; ethers; functional groups; functional polymers; gas adsorption; gas permeability; gases; metallic matrix composites; multiwalled carbon nanotubes (MWCN); nanocomposites; phase interfaces; polymer matrix composites; gas permeable membranes
Fields of Research : 09 Engineering > 0904 Chemical Engineering > 090404 Membrane and Separation Technologies
09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
Identification Number or DOI: 10.1021/jp1120965
URI: http://eprints.usq.edu.au/id/eprint/31156

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