The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

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

  • developing a novel alkaline anion exchange membrane derived from poly ether imide for improved ionic conductivity
    Polymers for Advanced Technologies, 2010
    Co-Authors: Guigui Wang, Yiming Weng, Dong Xie, Jun Zhao, Deryn Chu, Rongrong Chen
    Abstract:

    We have developed a novel alkaline anion exchange membrane derived from poly(ether-imide) for improved ionic conductivity. The effects of several important parameters on the Chloromethylation of the membrane were investigated. These parameters included reaction temperature, reaction time, concentration of Chloromethylation agent, concentration of polymer, and the amount of catalyst. The quaternization of the synthesized chloromethylated polymer was studied as well. The results show that all the studied parameters exhibited significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent played a key role in increasing the chloromethyl functional group attachment onto the polymer. It was found that the gelation could be avoided if these reaction parameters were controlled. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and optimize the conductivity of the membrane even though the functional chloromethyl groups attached to the polymer are limited. Copyright © 2009 John Wiley & Sons, Ltd.

  • preparation of a functional poly ether imide membrane for potential alkaline fuel cell applications Chloromethylation
    Journal of Applied Polymer Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Che, Ju Zhao, Dong Xie
    Abstract:

    We have developed a novel poly(ether imide)-based alkaline anion-exchange membrane. The effects of several important parameters on the Chloromethylation of the membrane have been investigated. These parameters include the reaction temperature, reaction time, concentration of the Chloromethylation agent, concentration of the polymer, and amount of the catalyst. The results show that all the studied parameters have significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent plays a key role in increasing the attachment of chloromethyl functional groups onto the polymer. It ha been found that gelation can be avoided if these reaction parameters are controlled. This study also provides useful information for the successful Chloromethylation of other membrane-related polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Deryn Chu, Rongrong Chen, Dong Xie
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Chen
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

Dong Xie - One of the best experts on this subject based on the ideXlab platform.

  • developing a novel alkaline anion exchange membrane derived from poly ether imide for improved ionic conductivity
    Polymers for Advanced Technologies, 2010
    Co-Authors: Guigui Wang, Yiming Weng, Dong Xie, Jun Zhao, Deryn Chu, Rongrong Chen
    Abstract:

    We have developed a novel alkaline anion exchange membrane derived from poly(ether-imide) for improved ionic conductivity. The effects of several important parameters on the Chloromethylation of the membrane were investigated. These parameters included reaction temperature, reaction time, concentration of Chloromethylation agent, concentration of polymer, and the amount of catalyst. The quaternization of the synthesized chloromethylated polymer was studied as well. The results show that all the studied parameters exhibited significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent played a key role in increasing the chloromethyl functional group attachment onto the polymer. It was found that the gelation could be avoided if these reaction parameters were controlled. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and optimize the conductivity of the membrane even though the functional chloromethyl groups attached to the polymer are limited. Copyright © 2009 John Wiley & Sons, Ltd.

  • preparation of a functional poly ether imide membrane for potential alkaline fuel cell applications Chloromethylation
    Journal of Applied Polymer Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Che, Ju Zhao, Dong Xie
    Abstract:

    We have developed a novel poly(ether imide)-based alkaline anion-exchange membrane. The effects of several important parameters on the Chloromethylation of the membrane have been investigated. These parameters include the reaction temperature, reaction time, concentration of the Chloromethylation agent, concentration of the polymer, and amount of the catalyst. The results show that all the studied parameters have significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent plays a key role in increasing the attachment of chloromethyl functional groups onto the polymer. It ha been found that gelation can be avoided if these reaction parameters are controlled. This study also provides useful information for the successful Chloromethylation of other membrane-related polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Deryn Chu, Rongrong Chen, Dong Xie
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

Rongrong Chen - One of the best experts on this subject based on the ideXlab platform.

  • developing a novel alkaline anion exchange membrane derived from poly ether imide for improved ionic conductivity
    Polymers for Advanced Technologies, 2010
    Co-Authors: Guigui Wang, Yiming Weng, Dong Xie, Jun Zhao, Deryn Chu, Rongrong Chen
    Abstract:

    We have developed a novel alkaline anion exchange membrane derived from poly(ether-imide) for improved ionic conductivity. The effects of several important parameters on the Chloromethylation of the membrane were investigated. These parameters included reaction temperature, reaction time, concentration of Chloromethylation agent, concentration of polymer, and the amount of catalyst. The quaternization of the synthesized chloromethylated polymer was studied as well. The results show that all the studied parameters exhibited significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent played a key role in increasing the chloromethyl functional group attachment onto the polymer. It was found that the gelation could be avoided if these reaction parameters were controlled. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and optimize the conductivity of the membrane even though the functional chloromethyl groups attached to the polymer are limited. Copyright © 2009 John Wiley & Sons, Ltd.

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Deryn Chu, Rongrong Chen, Dong Xie
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Chen
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

Yiming Weng - One of the best experts on this subject based on the ideXlab platform.

  • developing a novel alkaline anion exchange membrane derived from poly ether imide for improved ionic conductivity
    Polymers for Advanced Technologies, 2010
    Co-Authors: Guigui Wang, Yiming Weng, Dong Xie, Jun Zhao, Deryn Chu, Rongrong Chen
    Abstract:

    We have developed a novel alkaline anion exchange membrane derived from poly(ether-imide) for improved ionic conductivity. The effects of several important parameters on the Chloromethylation of the membrane were investigated. These parameters included reaction temperature, reaction time, concentration of Chloromethylation agent, concentration of polymer, and the amount of catalyst. The quaternization of the synthesized chloromethylated polymer was studied as well. The results show that all the studied parameters exhibited significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent played a key role in increasing the chloromethyl functional group attachment onto the polymer. It was found that the gelation could be avoided if these reaction parameters were controlled. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and optimize the conductivity of the membrane even though the functional chloromethyl groups attached to the polymer are limited. Copyright © 2009 John Wiley & Sons, Ltd.

  • preparation of a functional poly ether imide membrane for potential alkaline fuel cell applications Chloromethylation
    Journal of Applied Polymer Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Che, Ju Zhao, Dong Xie
    Abstract:

    We have developed a novel poly(ether imide)-based alkaline anion-exchange membrane. The effects of several important parameters on the Chloromethylation of the membrane have been investigated. These parameters include the reaction temperature, reaction time, concentration of the Chloromethylation agent, concentration of the polymer, and amount of the catalyst. The results show that all the studied parameters have significant impacts on Chloromethylation. Among them, the concentration of the Chloromethylation agent plays a key role in increasing the attachment of chloromethyl functional groups onto the polymer. It ha been found that gelation can be avoided if these reaction parameters are controlled. This study also provides useful information for the successful Chloromethylation of other membrane-related polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Deryn Chu, Rongrong Chen, Dong Xie
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

  • developing a polysulfone based alkaline anion exchange membrane for improved ionic conductivity
    Journal of Membrane Science, 2009
    Co-Authors: Guigui Wang, Yiming Weng, Rongrong Chen
    Abstract:

    Abstract Alkaline anion exchange membranes of high ionic conductivities were made from polysulfone by adding a chloromethyl pendant group to the polysulfone at different reaction times and temperatures, followed by reacting the chloromethyl group with different amines to form different quaternary ammonium pendant groups which acted as the counterion for hydroxide anion. The effects of temperature and time on Chloromethylation of the polymer were investigated and the Chloromethylation was optimized. Furthermore, different approaches for quaternization of the synthesized chloromethylated polymer were studied. The results show that both temperature and time exhibited significant impacts on Chloromethylation and gelation. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and also could optimize the conductivity of the membrane even though the accessible functional chloromethyl groups were limited. The developed AAEM showed the ionic conductivity up to 3.1 × 10 −2  S/cm at room temperature. Increasing temperature increased the ionic conductivity up to 7.33 × 10 −2  S/cm. The formed AAEM was stable in a concentrated base up to 8.0 M KOH at room temperature.

Michael A Hickner - One of the best experts on this subject based on the ideXlab platform.

  • anion exchange fuel cell membranes prepared from c h borylation and suzuki coupling reactions
    Macromolecules, 2014
    Co-Authors: Angela D Mohanty, Michael A Hickner
    Abstract:

    Of the polymer materials investigated as anion exchange membranes, trimethylbenzylammonium-containing polysulfones are the most extensively studied. They are commonly prepared by Chloromethylation of the aromatic backbone or radical bromination of benzylic carbons, followed by a Menshutkin reaction between a tertiary amine and the benzyl halide. To overcome synthetic limitations involved with these two methods, we report the preparation of an anion exchange membrane by means of iridium-catalyzed C–H borylation followed by palladium-catalyzed Suzuki coupling. Owing to the use of mild reaction conditions and high efficiency of these metal-catalyzed reactions, we were able to minimize side reactions and easily control the degree of functionalization for a series of trimethylbenzylammonium-containing polysulfones. The resulting membranes exhibited lower water uptake while maintaining similar hydroxide conductivity and functional group stability as compared to the corresponding Chloromethylation-prepared anion...

  • Anion Exchange Fuel Cell Membranes Prepared from C–H Borylation and Suzuki Coupling Reactions
    2014
    Co-Authors: Angela D. Mohanty, Michael A Hickner, Yeong-beom Lee, Liang Zhu, Chulsung Bae
    Abstract:

    Of the polymer materials investigated as anion exchange membranes, trimethylbenzylammonium-containing polysulfones are the most extensively studied. They are commonly prepared by Chloromethylation of the aromatic backbone or radical bromination of benzylic carbons, followed by a Menshutkin reaction between a tertiary amine and the benzyl halide. To overcome synthetic limitations involved with these two methods, we report the preparation of an anion exchange membrane by means of iridium-catalyzed C–H borylation followed by palladium-catalyzed Suzuki coupling. Owing to the use of mild reaction conditions and high efficiency of these metal-catalyzed reactions, we were able to minimize side reactions and easily control the degree of functionalization for a series of trimethylbenzylammonium-containing polysulfones. The resulting membranes exhibited lower water uptake while maintaining similar hydroxide conductivity and functional group stability as compared to the corresponding Chloromethylation-prepared anion exchange membrane materials