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Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

Khan MM, Filiz V, Bengtson G, Shishatskiy S, Rahman M, Abetz V - Nanoscale Res Lett (2012)

Bottom Line: The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs.The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity.The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-StraSSe 1, 21502, Geesthacht, Germany. volker.abetz@hzg.de.

ABSTRACT
The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

No MeSH data available.


Related in: MedlinePlus

SEM images of surface and cross section of PIM-1. (a, b), MMM of MWCNTs (c, d) and f-MWCNTs (e, f).
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Figure 6: SEM images of surface and cross section of PIM-1. (a, b), MMM of MWCNTs (c, d) and f-MWCNTs (e, f).

Mentions: Figure6 shows the SEM images of PIM-1 and PIM-1 incorporated with pristine and f- MWCNTs (1 wt.%) MMM. It was observed that the average thickness of all these membranes was 0.75 μm (Figure6). When pristine MWCNTs were incorporated into the PIM-1 matrix, the resulting MMM contained agglomerated MWCNTs showed by white circle, which are clearly observable from the cross section (Figure6d). The surface and cross section images of f-MWCNTs MMM indicated that most of the functionalized MWCNTs were well dispersed in PIM-1 matrix (Figure6e, f). There was also no evidence of interfacial voids in the prepared MMM. The explanation for the agglomeration of MWCNTs in the polymer matrix was that the interactions between the MWCNTs (π-π interaction) are stronger than that with the polymer matrix[29-32]. Therefore, the pristine MWCNTs tend to agglomerate and do not distribute well in PIM-1 matrix. The presence of PEG on the surface of MWCNTs appeared to de-bundle the highly entangled MWCNTs which resulted in improved dispersion throughout the PIM-1 matrix.


Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

Khan MM, Filiz V, Bengtson G, Shishatskiy S, Rahman M, Abetz V - Nanoscale Res Lett (2012)

SEM images of surface and cross section of PIM-1. (a, b), MMM of MWCNTs (c, d) and f-MWCNTs (e, f).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3526465&req=5

Figure 6: SEM images of surface and cross section of PIM-1. (a, b), MMM of MWCNTs (c, d) and f-MWCNTs (e, f).
Mentions: Figure6 shows the SEM images of PIM-1 and PIM-1 incorporated with pristine and f- MWCNTs (1 wt.%) MMM. It was observed that the average thickness of all these membranes was 0.75 μm (Figure6). When pristine MWCNTs were incorporated into the PIM-1 matrix, the resulting MMM contained agglomerated MWCNTs showed by white circle, which are clearly observable from the cross section (Figure6d). The surface and cross section images of f-MWCNTs MMM indicated that most of the functionalized MWCNTs were well dispersed in PIM-1 matrix (Figure6e, f). There was also no evidence of interfacial voids in the prepared MMM. The explanation for the agglomeration of MWCNTs in the polymer matrix was that the interactions between the MWCNTs (π-π interaction) are stronger than that with the polymer matrix[29-32]. Therefore, the pristine MWCNTs tend to agglomerate and do not distribute well in PIM-1 matrix. The presence of PEG on the surface of MWCNTs appeared to de-bundle the highly entangled MWCNTs which resulted in improved dispersion throughout the PIM-1 matrix.

Bottom Line: The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs.The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity.The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-StraSSe 1, 21502, Geesthacht, Germany. volker.abetz@hzg.de.

ABSTRACT
The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

No MeSH data available.


Related in: MedlinePlus