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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

Long term stability of PIM-1. PIM-1 MMM incorporated with f-MWCNTs measured as (a) O2 permeance; (b) relative permeance. Black squares, PIM-1; red circles, 0.5 wt.% MMM; blue triangles, 1 wt.% MMM; green inverted triangles, 2 wt.% MMM; and pink diamonds, 3 wt.% MMM. Temperature, 27°C and feed pressure, 2 bar.
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Figure 8: Long term stability of PIM-1. PIM-1 MMM incorporated with f-MWCNTs measured as (a) O2 permeance; (b) relative permeance. Black squares, PIM-1; red circles, 0.5 wt.% MMM; blue triangles, 1 wt.% MMM; green inverted triangles, 2 wt.% MMM; and pink diamonds, 3 wt.% MMM. Temperature, 27°C and feed pressure, 2 bar.

Mentions: The long-term stability of f-MWCNTs containing MMM continuously exposed to air at 2 bar pressure was monitored and the results are shown in Figure8. The O2 permeance of the fabricated membranes was measured over a period of 550 h Figure8a. It was observed that the O2 permeance of f-MWCNTs MMM slowly and gradually decreased with time compared with the much more significant O2 permeance loss as a function of time observed for the pure PIM-1 composite membrane. The permeance trends for f-MWCNTs MMM are PIM-1 < 0.5 < 1 < 3 < 2 wt.%. Among these 2 wt.% f-MWCNTs MMM shows the better performance in long-term stability. A similar trend was found for the change of N2 permeance as a function of time for different f-MWCNTs MMM. Compared to PIM-1 composite membrane, the f-MWCNTs MMM tend to have better long-term stability, although none of the studied membranes has shown permeance stabilization after 550 h of continuous experiments.


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)

Long term stability of PIM-1. PIM-1 MMM incorporated with f-MWCNTs measured as (a) O2 permeance; (b) relative permeance. Black squares, PIM-1; red circles, 0.5 wt.% MMM; blue triangles, 1 wt.% MMM; green inverted triangles, 2 wt.% MMM; and pink diamonds, 3 wt.% MMM. Temperature, 27°C and feed pressure, 2 bar.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 8: Long term stability of PIM-1. PIM-1 MMM incorporated with f-MWCNTs measured as (a) O2 permeance; (b) relative permeance. Black squares, PIM-1; red circles, 0.5 wt.% MMM; blue triangles, 1 wt.% MMM; green inverted triangles, 2 wt.% MMM; and pink diamonds, 3 wt.% MMM. Temperature, 27°C and feed pressure, 2 bar.
Mentions: The long-term stability of f-MWCNTs containing MMM continuously exposed to air at 2 bar pressure was monitored and the results are shown in Figure8. The O2 permeance of the fabricated membranes was measured over a period of 550 h Figure8a. It was observed that the O2 permeance of f-MWCNTs MMM slowly and gradually decreased with time compared with the much more significant O2 permeance loss as a function of time observed for the pure PIM-1 composite membrane. The permeance trends for f-MWCNTs MMM are PIM-1 < 0.5 < 1 < 3 < 2 wt.%. Among these 2 wt.% f-MWCNTs MMM shows the better performance in long-term stability. A similar trend was found for the change of N2 permeance as a function of time for different f-MWCNTs MMM. Compared to PIM-1 composite membrane, the f-MWCNTs MMM tend to have better long-term stability, although none of the studied membranes has shown permeance stabilization after 550 h of continuous experiments.

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