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An anion exchange resin having a hydrophobic unit with divalent hydrophobic groups bonded to each other via an ether bond, the divalent hydrophobic groups being composed of one aromatic ring, or being composed of a plurality of aromatic rings which are bonded to each other via a divalent hydrocarbon group, carbon-carbon bond or the like; and a hydrophilic unit having divalent hydrophilic groups bonded to each other via carbon-carbon bond, the divalent hydrophilic groups being composed of one aromatic ring, or being composed of a plurality of aromatic rings which are bonded to each other via a divalent hydrocarbon group or carbon-carbon bond, the aromatic ring or at least one of the aromatic rings having an anion exchange group are bonded via carbon-carbon bond.


Shimada M.,Yamanashi University | Shimada M.,Takahata Precision Japan Co. | Shimada M.,Japan Science and Technology Agency | Shimada S.,Yamanashi University | And 6 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2016

Synthesis and properties of anion conductive aromatic block copolymers, QPE-bl-3, QPE-bl-3 M2, and M4, containing fluorenylidene biphenylene groups as scaffold for ammonium groups are described. These copolymers share the same main chain structure, but the position and the number of ammonium groups on a fluorenyl group differ. High molecular weight quaternized block copolymers were obtained via typical chloromethylation reaction or using preaminated monomers, and were well-characterized by 1H NMR spectra. Self-standing bendable membranes were obtained by solution casting. QPE-bl-3 M4 membranes containing four ammonium groups per hydrophilic repeat unit (highest ammonium density) in the hydrophilic block exhibited well developed phase-separated morphology, while QPE-bl-3 membranes containing two ammonium groups per hydrophilic repeat unit exhibited high anion conductivity. The highest anion conductivity (104 mS/cm) was obtained with QPE-bl-3 membrane (IEC = 2.1 meq/g) at 80 C in water. An H2/O2 alkaline fuel cell was operable with the membrane to achieve 62 mW/cm2 of the maximum power density at 161 mA/cm2 of the current density. © 2015 Wiley Periodicals, Inc.


Yokota N.,Yamanashi University | Yokota N.,Takahata Precision Japan Co. | Yokota N.,Japan Science and Technology Agency | Shimada M.,Yamanashi University | And 15 more authors.
Macromolecules | Year: 2014

The synthesis and properties of anion conductive aromatic copolymers containing oligophenylene moieties as a scaffold for quaternized ammonium groups are reported. Our new hydrophilic components consist of a chemically robust oligophenylene main chain modified with a high density of ionic groups. A partially fluorinated oligo(arylene ether) was employed as a hydrophobic block. The targeted copolymers (QPE-bl-9) were synthesized via nickel-mediated coupling polymerization, followed by chloromethylation, quaternization, and ion exchange reactions. QPE-bl-9 provided tough, bendable membranes by solution casting. The resulting membrane with the highest ion exchange capacity (IEC = 2.0 mequiv g-1) exhibited high hydroxide ion conductivity (138 mS cm-1) in water at 80 °C. Reasonable alkaline stability of QPE-bl-9 membrane was confirmed in 1 M KOH aqueous solution for 1000 h at 40 °C. A noble metal-free fuel cell with QPE-bl-9 used as the membrane and electrode binder was successfully operated. A maximum power density of 510 mW cm-2 was achieved at a current density of 1.20 A cm-2 with hydrazine as the fuel and O2 as the oxidant. © 2014 American Chemical Society.


Yokota N.,Yamanashi University | Yokota N.,Takahata Precision Japan Co. | Yokota N.,Japan Science and Technology Agency | Ono H.,Yamanashi University | And 10 more authors.
ACS Applied Materials and Interfaces | Year: 2014

A novel series of aromatic block copolymers composed of fluorinated phenylene and biphenylene groups and diphenyl ether (QPE-bl-5) or diphenyl sulfide (QPE-bl-6) groups as a scaffold for quaternized ammonium groups is reported. The block copolymers were synthesized via aromatic nucleophilic substitution polycondensation, chloromethylation, quaternization, and ion exchange reactions. The block copolymers were soluble in organic solvents and provided thin and bendable membranes by solution casting. The membranes exhibited well-developed phase-separated morphology based on the hydrophilic/hydrophobic block copolymer structure. The membranes exhibited mechanical stability as confirmed by DMA (dynamic mechanical analyses) and low gas and hydrazine permeability. The QPE-bl-5 membrane with the highest ion exchange capacity (IEC = 2.1 mequiv g-1) exhibited high hydroxide ion conductivity (62 mS cm-1) in water at 80 °C. A noble metal-free fuel cell was fabricated with the QPE-bl-5 as the membrane and electrode binder. The fuel cell operated with hydrazine as a fuel exhibited a maximum power density of 176 mW cm-2 at a current density of 451 mA cm-2. © 2014 American Chemical Society.


Nagase K.,Yamanashi University | Nagase K.,Takahata Precision Japan Co. | Motegi H.,Mizuho Information and Research Institute | Yoneda M.,Mizuho Information and Research Institute | And 6 more authors.
ChemElectroChem | Year: 2015

Visualization of the oxygen partial pressure (pO(2)) was performed at the surface of a gas diffusion layer (GDL) and the upper part of the gas-flow channel of the cathode of an operating polymer electrolyte fuel cell (PEFC) with straight flow channels by using an oxygen-sensitive luminescent dye film. The gradient of pO(2) inside a channel was clearly observed, even on the GDL surface across the channel. A numerical simulation was performed to understand the reaction distributions inside the PEFC. By visualization and numerical simulation, the distributions of pO(2), the current density, water concentration, and temperature in the operating PEFC were obtained, and the relationships between the parameters were studied. Supersaturated water inside the cell was found both experimentally and computationally. pO(2) and the water concentration were concluded to be the two most important factors in determining the distribution of power generation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Nishino E.,Daihatsu Motor Co. | Yamada J.,Daihatsu Motor Co. | Asazawa K.,Daihatsu Motor Co. | Yamaguchi S.,Daihatsu Motor Co. | And 4 more authors.
Chemistry Letters | Year: 2016

The properties of anion-exchange membranes composed of fluorinated block copoly(arylene ether)s, QPE-bl-3, were investigated. QPE-bl-3 membranes exhibited high chemical stability under accelerated testing conditions. Reasonably high fuel cell performance was obtained with QPE-bl-3, hydrazine hydrate as a fuel, and non-platinum catalysts. © 2016 The Chemical Society of Japan.


Nagase K.,Yamanashi University | Nagase K.,Takahata Precision Japan Co. | Suga T.,Waseda University | Nagumo Y.,Shimadzu Corporation | And 4 more authors.
Journal of Power Sources | Year: 2015

(Figure Presented). Visualization inside polymer electrolyte fuel cells (PEFCs) for elucidating the reaction distributions is expected to improve the performance, durability, and stability. An oxygen-sensitive film of a luminescent porphyrin was used to visualize the oxygen partial pressures in five straight gas-flow channels of a running PEFC with liquid-water blockages formed at the end of the channels. The blockage greatly lowered and unstabilized the cell voltage. The oxygen partial pressure decreased nearly to 0 kPa in the blocked channel. With a water blockage in a channel, the oxygen partial pressures in the adjacent channels were lowered due to an extra demand of oxygen consumption. When the number of the blocked channels increased, the oxygen partial pressure in the unblocked channels became much lowered. When the water blockages disappeared, the oxygen partial pressures quickly returned to the values before plugging. The influence of the cross flows of air through the gas diffusion layers in straight channels was much smaller than that in serpentine flow channels. © 2014 Elsevier B.V. All rights reserved.


Hara M.,Yamanashi University | Kimura T.,Yamanashi University | Nakamura T.,Yamanashi University | Shimada M.,Yamanashi University | And 7 more authors.
Langmuir | Year: 2016

Anion conductivity at the surfaces of two anion-exchange membranes (AEMs), quaternized ammonium poly(arylene ether) multiblock copolymer (QPE-bl-3) and quaternized ammonium poly(arylene perfluoro-alkylene) copolymer (QPAF-1), synthesized by our group was investigated using current-sensing atomic force microscopy under purified air at various relative humidities. The anion-conducting spots were distributed inhomogeneously on the surface of QPE-bl-3, and the total areas of the anion-conducting spots and the current at each spot increased with humidity. The anion-conductive areas on QPAF-1 were found on the entire surface even at a low humidity. Distribution of the anion-conducting spots on the membrane was found to directly affect the performance of an AEM fuel cell. © 2016 American Chemical Society.


Akiyama R.,Yamanashi University | Yokota N.,Takahata Precision Japan Co. | Nishino E.,Daihatsu Motor Co. | Asazawa K.,Daihatsu Motor Co. | Miyatake K.,Yamanashi University
Macromolecules | Year: 2016

A novel series of anion conductive aromatic copolymers were synthesized from preaminated monomers (2,5-, 3,5-, or 2,4-dichloro-N,N-dimethylbenzylamine), and their properties were investigated for alkaline fuel cell applications. The targeted copolymers (QPE-bl-11a, -11b, and -11c) were synthesized via nickel-mediated Ullmann coupling polymerization, followed by quaternization and ion exchange reactions. Unlike the conventional method involving chloromethylation or bromination, this method provided copolymers with well-defined chemical structure. The hydrophilic components of the copolymers were composed of chemically stable phenylene main chain modified with high-density ammonium groups. Oligo(arylene ether sulfone ketone)s were employed as a hydrophobic block. QPE-bl-11a gave tough and bendable membranes by solution casting. The obtained membrane with the highest ion exchange capacity value (IEC = 2.47 mequiv g-1) showed high hydroxide ion conductivity (130 mS cm-1) in water at 80 °C. The QPE-bl-11a membrane showed reasonable alkaline stability in 1 M KOH aqueous solution for 1000 h at 60 °C. A platinum-free fuel cell was successfully operated with hydrazine as a fuel, the QPE-bl-11a as a membrane, and an electrode binder. The maximum power density of 380 mW cm-2 was achieved at a current density of 1020 mA cm-2 with O2. © 2016 American Chemical Society.


PubMed | Yamanashi University and Takahata Precision Japan Co.
Type: Journal Article | Journal: Langmuir : the ACS journal of surfaces and colloids | Year: 2016

Anion conductivity at the surfaces of two anion-exchange membranes (AEMs), quaternized ammonium poly(arylene ether) multiblock copolymer (QPE-bl-3) and quaternized ammonium poly(arylene perfluoro-alkylene) copolymer (QPAF-1), synthesized by our group was investigated using current-sensing atomic force microscopy under purified air at various relative humidities. The anion-conducting spots were distributed inhomogeneously on the surface of QPE-bl-3, and the total areas of the anion-conducting spots and the current at each spot increased with humidity. The anion-conductive areas on QPAF-1 were found on the entire surface even at a low humidity. Distribution of the anion-conducting spots on the membrane was found to directly affect the performance of an AEM fuel cell.

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