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Matthias Wessling - One of the best experts on this subject based on the ideXlab platform.

  • a Polyelectrolyte Membrane based vanadium air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

  • A Polyelectrolyte Membrane-based vanadium/air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

Myoungseon Gong - One of the best experts on this subject based on the ideXlab platform.

  • Photochemical anchoring of Polyelectrolyte to the electrode surface using polymeric silane-coupling agents and their water durability
    Macromolecular Research, 2011
    Co-Authors: Myoungseon Gong
    Abstract:

    This paper reports a simple effective way to photochemically attach a Polyelectrolyte layer to an electrode substrate. The system is based on photoreactive benzophenone (BP)-containing copolymers that are bound to alumina surfaces via an alkoxysilane coupling reaction. The alumina substrate was then covered with a BP film that can be reacted with the Polyelectrolyte by irradiation with UV light. As a result of the photochemical reaction, the Polyelectrolyte was bound covalently to the electrode surfaces. As an example, a thin layer of copolymer of [2-(acryloyloxy)ethyl]trimethyl ammonium chloride (AETAC), styrene (ST), 2-hydroxyethylacrylate (HEA), and 4-acryloxybenzophenone (BPA) (AETAC/ST/HEA/BPA=60/33/4/3) was attached successfully. A pretreatment of the substrate with BP-containing polymeric silane-coupling reagents, AETAC/3-(trimethoxysilyl)propyl methacrylate (TMSPM)/HEA/BPA=50/30/10/10 or TMSPM/HEA/BPA=50/25/25, was performed to improve the water durability and stability at high temperatures and humidity. Their water durability, high temperature/humidity stabilities and long-term stability were evaluated to confirm their usefulness as a humidity-sensing Polyelectrolyte Membrane.

  • preparation of water durable humidity sensor by attachment of Polyelectrolyte Membrane to electrode substrate by photochemical crosslinking reaction
    Sensors and Actuators B-chemical, 2010
    Co-Authors: Myoungseon Gong
    Abstract:

    Abstract New photo-crosslinkable benzophenone-containing Polyelectrolytes were prepared by copolymerization of quaternary ammonium salt-containing monomer [2-(acryloyloxy)ethyl] dimethyl propyl ammonium bromide (AEPAB), styrene (ST), 2-hydroxyethylmethacrylate (HEMA), and 4-acryloyloxybenzophenone (BPA). These Polyelectrolytes are self-crosslinkable copolymers for humidity-sensitive Polyelectrolytes composed of copolymers with different contents of AEPAB/ST/HEMA/BPA = 70/25/3/2, 70/25/2/3, 70/23/5/2, and 70/23/4/3. Pretreatment of the alumina substrate with 3-glycidoxypropyltrimethoxysilane (GPTMS) containing silane-coupling agent was performed to anchor the humidity-sensitive Membrane to the substrate through covalent bonds. The sensors were irradiated with UV light, causing the electronically excited benzophenone molecules to form a crosslinking reaction. The resistance ranged from 107 Ω to 103 Ω between 20% relative humidity (RH) and 95% RH, the humidity range required for a sensor operating at ambient humidity. Their water durability, long-term stability under various environments, hysteresis, and response and recovery times were measured and evaluated as a humidity-sensing Membrane.

  • photochemical attachment of Polyelectrolyte Membrane to electrode substrate and their humidity sensitive properties
    Sensors and Actuators B-chemical, 2010
    Co-Authors: Myoungseon Gong
    Abstract:

    Abstract New cinnamate group-containing copolymers for a humidity-sensitive Polyelectrolyte were prepared by copolymerization of [2-[(methacryloyloxy)ethyl]dimethyl]propyl ammonium bromide (MEPAB), methyl methacrylate (MMA) and 2-(cinnamyloxy)ethyl methacrylate (CEMA). They were self-crosslinkable terpolymers composed of different contents of MEPAB/MMA/CEMA = 70/27/3, 70/25/5, 70/23/7 and 70/20/10. Pretreatment of the alumina substrate with 3-(triethoxysilyl)propyl cinnamate (TESPC) containing silane-coupling agent was performed to attach the humidity-sensitive Membrane to the substrate through covalent bonds. The sensors were irradiated with UV light, causing the electronically excited cinnamate molecules to form a crosslinking reaction via the [2π + 2π] addition. The impedance ranged from 10 7 to 10 3  Ω between 20 and 95%RH, which was required for a humidity sensor operating at ambient humidity. Water durability, hysteresis, response time and long-term stability at high temperature and humidity were also measured and estimated.

  • humidity sensors fabricated with Polyelectrolyte Membrane using an ink jet printing technique and their electrical properties
    Sensors and Actuators B-chemical, 2005
    Co-Authors: Kwangchun Chung, Myoungseon Gong
    Abstract:

    Humidity-sensitive Membranes made of ionene oligomer have been fabricated on the electrode substrate using a commercial drop-on-demand ink-jet printing system using a 15 μm diameter nozzle driven by a piezoelectric device. After deposition and evaporation of the solvent, the humidity sensors have been cross-linked by heating. Their humidity-sensitive properties have been determined by using a thermostatic humidity chamber. Electrical measurements under various relative humidity were performed. The humidity-sensitive characteristics of sensors obtained by ink-jet printing technique were compared with that of dip-coating method. Humidity sensors showed a decrease in impedance as an increase of relative humidity and their impedance characteristics are in a close agreement.

Seyed Schwan Hosseiny - One of the best experts on this subject based on the ideXlab platform.

  • a Polyelectrolyte Membrane based vanadium air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

  • A Polyelectrolyte Membrane-based vanadium/air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

Michel Saakes - One of the best experts on this subject based on the ideXlab platform.

  • a Polyelectrolyte Membrane based vanadium air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

  • A Polyelectrolyte Membrane-based vanadium/air redox flow battery
    Electrochemistry Communications, 2011
    Co-Authors: Seyed Schwan Hosseiny, Michel Saakes, Matthias Wessling
    Abstract:

    Abstract A vanadium/air redox flow battery (VARFB) was developed using on one side 2 M V 2+ /V 3+ solution in 3 M H 2 SO 4 and H 2 O/O 2 on the other side as redox couples. The vanadium side is identical to the already available all vanadium redox flow battery. Air is used as the second redox couple in order to decrease the weight and increase the weight specific power output. In the VARFB cell, a Membrane electrode assembly (MEA) with a new reversible air electrode is applied. In this short communication, we show that the VARFB operated at 80 °C has a voltage efficiency of 46% and an energy efficiency of 45.7%. Although somewhat lower than for other redox flow batteries like all vanadium, having 81% voltage efficiency and 73% energy efficiency, the weight specific storage capacity is almost doubled here since in our system only one liquid redox couple has to be stored.

M S Gong - One of the best experts on this subject based on the ideXlab platform.

  • Humidity sensors fabricated with Polyelectrolyte Membrane using an ink jet printing technique and their electrical properties
    Sensors and Actuators B-Chemical, 2005
    Co-Authors: C W Lee, Y.-s. Han, D H Nam, K. C. Chung, M S Gong
    Abstract:

    Humidity-sensitive Membranes made of ionene oligomer have been fabricated on the electrode substrate using a commercial drop-on-demand ink-jet printing system using a 15 mu m diameter nozzle driven by a piezoelectric device. After deposition and evaporation of the solvent, the humidity sensors have been cross-linked by heating. Their humidity-sensitive properties have been determined by using a thermostatic humidity chamber. Electrical measurements under various relative humidity were performed. The humidity-sensitive characteristics of sensors obtained by ink-jet printing technique were compared with that of dip-coating method. Humidity sensors showed a decrease in impedance as an increase of relative humidity and their impedance characteristics are in a close agreement. (C) 2005 Elsevier B.V All rights reserved