Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
岸本 泰明; 井戸村 泰宏; Li, J.
プラズマ・核融合学会誌, 79(5), p.478 - 488, 2003/05
本稿では、時空間スケールを限定した単一の物理階層のみならず、階層間の相互作用が本質的役割を果たす現象の一つである「プラズマ中に発生する乱流と層流」に話題を限定し、多階層・複合概念が核融合プラズマの高性能に果たす役割の一端を紹介する。また、今後の構造形成に準拠した高性能の核融合研究を推進する上で、幅広い時空間スケールを包含する多階層シミュレーション研究の重要性について考察する。
前川 康成
no journal, ,
Radiation-induced grafting technique was applied to the development of proton- and anion-conducting electrolyte membranes (PEM and AEM) for hydrogen- and alkaline hydrated hydrazine-fuel cells. The graft-type PEM and AEM could solve the currently most concerned problems, conductivity and mechanical properties at low and high relative humidities (RH), respectively for a PEM and alkaline durability for a AEM. The hierarchical structures of ETFE-PEM and ETFE-AEM were investigated using small angle X-ray and neutron scattering (SAXS and SANS). The grafted ETFE membranes were characterized as being composed of conducting graft domains around ETFE lamellar crystals with a period of 20-30 nm and well-connected crystallite network domains with a d-range of 200-300 nm. The well-connected ion-channels around ETFE lamellar crystals and crystallite domains should be origin of high conductivity and mechanical properties of both graft-type PEM and AEM.
前川 康成
no journal, ,
Radiation-induced grafting technique was applied to the development of polymer electrolyte membranes (PEMs) for hydrogen-fuel cells. Mechanically and thermally stable poly(ethylene-co-tetrafluoroethylene) (ETFE) films could be converted to graft-type PEMs (ETFE-PEMs). Compared with Nafion, the PEMs showed superior conductivity and tensile strength under low (30%) and high (100%) relative humidity conditions, respectively. Using SAXS and USAXS, the ETFE-PEMs with IECs 2.7 mmol/g were characterized as being composed of graft polymer domains around lamellar crystals with a period of 20-30 nm and well-connected crystallite network domains with a d-range of 200-300 nm. From the above analysis, it is revealed that well interconnected ion-channels around the crystallites and the remaining lamellar crystals and crystallites in the graft-type PEMs were the origins of higher conductivity and tensile strengths, respectively, compared with conventional PEMs.
前川 康成
no journal, ,
Radiation-induced grafting technique was applied to the development of anion-conducting electrolyte membranes (AEMs) for alkaline hydrated hydrazine-fuel cells. The graft-type AEMs containing imidazolium graft-polymers attached on poly(ethylene-co-tetrafluoroethylene) (ETFE) could solve the currently most concerned problems, conductivity and alkaline durability at the operating condition (1M KOH, 80C). The hierarchical structures of the graft-type AEM were investigated using amall angle X-ray and neutron scattering (SAXS and SANS). The graft-type AEMs were composed of conducting graft domains around ETFE lamellar crystals with periods of 20-30 nm. The contrast variation method of SANS revealed that the ion-channels contained graft-polymers and water with a period of ca. 5 nm. It should be concluded that the graft-polymer containing ion-channels around ETFE lamellar crystals and crystallite domains should be origins of high conductivity and alkaline durability of graft-type AEMs.