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Hasegawa, Shin; Koshikawa, Hiroshi; Chen, J.; Maekawa, Yasunari
no journal, ,
We report herein the successful preparation of thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, poly(ether ether ketone) (PEEK), a so-called "super-engineering plastic". Polymer Electrolyte membrane of PEEK film with using radiation-induced graft polymerization has good proton conductivity (0.0068 S/cm) at 80
C and 30%RH. The elastic modulus of the grafted film showed twice higher than that of Nafion 212 film at 80 C and 100%RH.
Nagasawa, Naotsugu; Kanazawa, Shinichi*; Yoshii, Fumio; Tamada, Masao; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
Kato, Sho; Yamaki, Tetsuya; Yamamoto, Shunya; Hakoda, Teruyuki; Kawaguchi, Kazuhiro*; Kobayashi, Tomohiro*; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
In this research, we prepared WC nanoparticles by tungsten ion implantation in glassy carbon. The GC plates were implanted with 100-keV tungsten ion at nominal fluences between 2.4
10
1.810
ions/cm
by the Ion Implanter in TIARA. According to the Rutherford backscattering measurements, the implanted tungsten was distributed from 10 to 25 nm under the surface. The implanted samples were electrochemically etched to make the tungsten implanted layer exposed on the surface. The binding energy of W4f
obtained by X-ray photoelectron spectroscopy were 32.1 eV, which indicated the formation of WC as expected. The transmission electron microscope observation revealed that nanoparticles formation with diameters of less than 10 nm.
Yamaki, Tetsuya; Sekine, Toshihiko*; Sawada, Shinichi; Koshikawa, Hiroshi; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
We developed nano-struvture controlled polymer electrolyte membranes using high-energy heavy-ion irradiation for fuel cell applications. The investigation was performed in terms of the irradiating-ion dependence of the membrane dimensional stability. Poly(ethylene-co-tetrafluoroethylene) (ETFE) films were irradiated with 56 MeV 
N, 150 MeV 
Ar, and 450 MeV 
Xe from the TIARA cyclotron at fluences of 3.010
, 3.010
, and 3.010
ions/cm, respectively. The membranes at ion-exchange capacities (IECs) of 0.8 to 1.4 meq/g were prepared by our established method. Interestingly, the dimensional change was largely dependent on the irradiating ions in spite of the fixed IEC. This property was determined by the volume percentages of the tracks, which were estimated from the fluence and the track radii.
Nuryanthi, N.*; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Sawada, Shinichi; Hasegawa, Shin; Maekawa, Yasunari; Katsumura, Yosuke*
no journal, ,
We prepared ion-track membranes of poly(vinylidene fluoride) by chemical etching in a conductometric cell and then investigated how the applied AC voltage affected etching characteristics using scanning electron microscopy. The high voltage application had some effect on the final pore diameter, which seems inconsistent with the findings of our previous conductometric analysis, while shortening the breakthrough time greatly.
-ray pre-irradiation grafting; Effect of the structure of quaternary ammonium ionsKoshikawa, Hiroshi; Asano, Masaharu; Yamaki, Tetsuya; Yoshimura, Kimio; Maekawa, Yasunari; Yamamoto, Kazuya*; Shishitani, Hideyuki*; Asazawa, Koichiro*; Yamaguchi, Susumu*; Tanaka, Hirohisa*
no journal, ,
We investigated the effect of a linear carbon chain length (n) in quaternary ammonium ions, on the durability of ion conductivity of anion exchange membrane. The poly(ethylene-co-tetrafluoroethylene) grafted chloromethylstyrene film was quaternized in four different tertiary amines, that is, trimethylamine (n=1), dimethylethylamine (n=2), n-butyldimethylamine (n=4) and n-hexyldimethylamine (n=6) solutions. The n dependence of ion conductivity and chemical durability, which was represented by a residual percentage of the conductivity after treatment with a Fenton solution (3% hydrogen peroxide+ 4 ppm iron sulfate) at 80 C for 2 h. When n increased from 1 to 6, the ion conductivity decreased slightly, but it still stayed 20 mS/cm for n = 6. Interestingly, the chemical durability seemed to increase eight-fold at the same time. The chemical attack by hydroxyl radicals on the quaternary ammonium ions would be controlled by hydrophobicity and steric hindrance of the alkyl group.
Kimura, Atsushi; Nagasawa, Naotsugu; Taguchi, Mitsumasa
no journal, ,
no abstracts in English
C (Analysis by a chemiluminescence method)Sawada, Shinichi; Yamaki, Tetsuya; Asano, Masaharu; Sato, Tetsu*; Yamada, Rie*; Maekawa, Yasunari
no journal, ,
no abstracts in English