The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform

Liang Wang - One of the best experts on this subject based on the ideXlab platform.

  • Freeze/Thaw Durability Study of MWCNT-Reinforced Nafion Membranes
    Journal of The Electrochemical Society, 2011
    Co-Authors: Liang Wang, Ajay K. Prasad, Suresh G. Advani
    Abstract:

    Multi-walled carbon nanotubes (MWCNTs) were used to reinforce Nafion resin to improve freeze/thaw durability of proton exchange Membrane fuel cells (PEMFCs). Freeze/thaw cycling was conducted over 160 cycles for MWCNTs/Nafion Membranes as well as conventional Nafion-112 Membranes. The performance of the Membranes was measured by recording polarization curves after every 40 freeze/thaw cycles. The fuel cells with the MWCNT-Reinforced Membrane showed better performance than the conventional Nafion-112 Membrane after freeze/thaw cycling. H2 permeability tested by the chronocoulometry method showed that the Reinforced Membrane, due to its improved mechanical properties and lower swelling, was able to tolerate the cyclical expansion and contraction caused by ice formation better than a Nafion-112 Membrane of the same thickness. Scanning electron microscope tests revealed that the delamination between the catalyst layer and the Membrane is greatly reduced for the Reinforced Membrane due to its improved dimensional stability. A 100-hour durability test under standard conditions showed good operational stability of the MWCNT-Reinforced Nafion Membrane. © 2011 The Electrochemical Society. [DOI: 10.1149/2.082112jes] All rights reserved

  • MWCNTs Reinforced Nafion® Membrane prepared by a novel solution-cast method for PEMFC
    Journal of Power Sources, 2008
    Co-Authors: Liang Wang, Huamin Zhang, Danmin Xing, Y.h. Liu
    Abstract:

    An improved solution-cast method is presented to prepare multi-wall carbon nanotubes (mwcnts)/nafion (r) Reinforced Membrane with different mwcnts content (from 1 to 4 wt.%). mwcnts were oxidized by h, 02 and sodium hydroxide (naoh) was added into the mwcnts/nafion (r)/n,n-dimethylacetamide (dmaq solution. the long-term stability of the resulting dispersions was much better than the unmodified dispersions. the as-cast Membrane was observed by scanning electron microscope (sem). the mwcnts were uniformly dispersed in the nafion (r) resin. the tensile strength and the elongation at break were greatly improved for the Reinforced Membranes compared to the recast nafion (r) Membranes (54 and 27%, respectively). the fuel cell performance of the Reinforced Membranes with different mwcnts contents was also tested at 80 degrees c under fully humidified conditions. by comparing the mechanical properties, proton conductivity and fuel cell performance of the Reinforced Membranes, we concluded that the content of mwcnts in the Reinforced Membranes should not exceed 3 wt.%. the mwcnts/nafion (r) Reinforced Membrane with 3 wt.% mwcnts content showed the best mechanical characteristics and excellent fuel cell performance. (c) 2007 elsevier b.v. all rights reserved.

  • sulfonated polyimide ptfe Reinforced Membrane for pemfcs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

  • Sulfonated polyimide/PTFE Reinforced Membrane for PEMFCs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

Yijun Cai - One of the best experts on this subject based on the ideXlab platform.

  • sulfonated polyimide ptfe Reinforced Membrane for pemfcs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

  • Sulfonated polyimide/PTFE Reinforced Membrane for PEMFCs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

Huamin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • grafted porous ptfe partially fluorinated sulfonated poly arylene ether ketone composite Membrane for pemfc applications
    Journal of Membrane Science, 2011
    Co-Authors: Huamin Zhang, Cheng Bi, Shaohua Xiao, Yu Zhang, Xianfeng Li
    Abstract:

    A low cost and mechanically stabilized composite Membrane (25 mu m) based on grafted porous polytetrafluoroethylene (grPTFE) substrate and partially fluorinated sulfonated poly(arylene ether ketone) (FSPAEK) polymer was fabricated and investigated for proton exchange Membrane fuel cell (PEMFC) applications. In order to improve interfacial compatibility between hydrocarbon Membrane and Nafion (R) bonded electrode, partially fluorinated FSPAEK polymer was utilized as a proton conductor. In order to improve the combination between porous substrate and polymer, hydrophilic polystyrenesulfonate was chemically grafted onto hydrophobic PTFE substrate. The experimental results indicated that grPTFE showed richer sulfur concentration, lower water contact angle and better hydrophilicity, which made grPTFE substrate exhibit enhanced combination state with FSPAEK polymer. A relatively high mechanical stability of FSPAEK/grPTFE composite Membrane was obtained and was attributed to Reinforced effect of grPTFE substrate. The preliminary single cell evaluation had also confirmed FSPAEK/grPTFE composite Membrane was stable. As a novel, low cost and Reinforced Membrane, FSPAEK/grPTFE composite Membrane showed potential in PEMFC applications. (C) 2011 Elsevier B.V. All rights reserved.

  • MWCNTs Reinforced Nafion® Membrane prepared by a novel solution-cast method for PEMFC
    Journal of Power Sources, 2008
    Co-Authors: Liang Wang, Huamin Zhang, Danmin Xing, Y.h. Liu
    Abstract:

    An improved solution-cast method is presented to prepare multi-wall carbon nanotubes (mwcnts)/nafion (r) Reinforced Membrane with different mwcnts content (from 1 to 4 wt.%). mwcnts were oxidized by h, 02 and sodium hydroxide (naoh) was added into the mwcnts/nafion (r)/n,n-dimethylacetamide (dmaq solution. the long-term stability of the resulting dispersions was much better than the unmodified dispersions. the as-cast Membrane was observed by scanning electron microscope (sem). the mwcnts were uniformly dispersed in the nafion (r) resin. the tensile strength and the elongation at break were greatly improved for the Reinforced Membranes compared to the recast nafion (r) Membranes (54 and 27%, respectively). the fuel cell performance of the Reinforced Membranes with different mwcnts contents was also tested at 80 degrees c under fully humidified conditions. by comparing the mechanical properties, proton conductivity and fuel cell performance of the Reinforced Membranes, we concluded that the content of mwcnts in the Reinforced Membranes should not exceed 3 wt.%. the mwcnts/nafion (r) Reinforced Membrane with 3 wt.% mwcnts content showed the best mechanical characteristics and excellent fuel cell performance. (c) 2007 elsevier b.v. all rights reserved.

  • sulfonated polyimide ptfe Reinforced Membrane for pemfcs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

  • Sulfonated polyimide/PTFE Reinforced Membrane for PEMFCs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

Danmin Xing - One of the best experts on this subject based on the ideXlab platform.

  • MWCNTs Reinforced Nafion® Membrane prepared by a novel solution-cast method for PEMFC
    Journal of Power Sources, 2008
    Co-Authors: Liang Wang, Huamin Zhang, Danmin Xing, Y.h. Liu
    Abstract:

    An improved solution-cast method is presented to prepare multi-wall carbon nanotubes (mwcnts)/nafion (r) Reinforced Membrane with different mwcnts content (from 1 to 4 wt.%). mwcnts were oxidized by h, 02 and sodium hydroxide (naoh) was added into the mwcnts/nafion (r)/n,n-dimethylacetamide (dmaq solution. the long-term stability of the resulting dispersions was much better than the unmodified dispersions. the as-cast Membrane was observed by scanning electron microscope (sem). the mwcnts were uniformly dispersed in the nafion (r) resin. the tensile strength and the elongation at break were greatly improved for the Reinforced Membranes compared to the recast nafion (r) Membranes (54 and 27%, respectively). the fuel cell performance of the Reinforced Membranes with different mwcnts contents was also tested at 80 degrees c under fully humidified conditions. by comparing the mechanical properties, proton conductivity and fuel cell performance of the Reinforced Membranes, we concluded that the content of mwcnts in the Reinforced Membranes should not exceed 3 wt.%. the mwcnts/nafion (r) Reinforced Membrane with 3 wt.% mwcnts content showed the best mechanical characteristics and excellent fuel cell performance. (c) 2007 elsevier b.v. all rights reserved.

  • sulfonated polyimide ptfe Reinforced Membrane for pemfcs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

  • Sulfonated polyimide/PTFE Reinforced Membrane for PEMFCs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

Yunzhao Liu - One of the best experts on this subject based on the ideXlab platform.

  • sulfonated polyimide ptfe Reinforced Membrane for pemfcs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.

  • Sulfonated polyimide/PTFE Reinforced Membrane for PEMFCs
    Journal of Power Sources, 2007
    Co-Authors: Liang Wang, Huamin Zhang, Yunzhao Liu, Danmin Xing, Zhigang Shao, Yijun Cai
    Abstract:

    A sulfonated polyimide (SPI)/PTFE Reinforced Membrane was synthesized by impregnating PTFE (porous polytetrafluoroethylene) Membrane with a SPI/DMSO solution. The resulting composite Membrane was mechanically durable and quite thin relative to traditional perfluorosulfonated ionomer Membranes (PFSI). We expect the PTFE to restrict the swelling and dimensional change of the SPI when it is immersed into water. And the reinforcement with PTFE can increase the hydrolysis stability of the SPI due to the low swelling and low dimensional change. From ex-situ testing and a short term fuel cell "life" test, we conclude that the PTFE Reinforced sulfonated polyimide had a higher hydrolytic stability than pure sulfonated polyimide. The thin SPI/PTFE Membrane showed comparable fuel cell performance with the commercial NRE-212 Membrane with H(2)/O(2) at 80 degrees C under fully humidified conditions. The chemically modified Membrane with Nation layer showed good stability in a 120 h fuel cell test. (C) 2007 Elsevier B.V. All rights reserved.