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Asano, Masaharu; Yoshida, Masaru
Kogyo Zairyo, 52(12), p.65 - 69, 2004/12
no abstracts in English
Maekawa, Yasunari; Koshikawa, Hiroshi; Yoshida, Masaru
Polymer, 45(7), p.2291 - 2295, 2004/03
Times Cited Count：8 Percentile：28.47(Polymer Science)Ion track membranes of poly(ethylene terephthalate) (PET) are applied to the production of anisotropically conducting films possessing copper wires of less than sub-micron in diameter. The membranes possessing cylindrical pores of 1.9 
m and 200 nm in diameter were prepared by irradiation of 
Xe
ion beams followed by etching in an aqueous NaOH. Copper wires were deposited into the pores by electrochemical plating in aqueous copper sulfate solution to prepare the PET/Cu hybrid membranes. The copper wires with 1.9 m in diameter showed wavelike surface roughness, resulting from the roughness of the pore side wall, whereas the copper wires with 200 nm in diameter showed smooth surfaces. The resistances of the membranes measured by a four terminal resistance method are in good agreement with the calculated values, indicating that the hybrid membranes possess conductivity perpendicular to the membrane surfaces but not parallel to the surfaces.
Peng, L.; Apel, P.*; Maekawa, Yasunari; Yoshida, Masaru
Nuclear Instruments and Methods in Physics Research B, 168(4), p.527 - 532, 2000/08
Times Cited Count：12 Percentile：62.12(Instruments & Instrumentation)no abstracts in English
Asano, Masaharu; Maekawa, Yasunari; Yoshida, Masaru
JAERI-Review 99-025, TIARA Annual Report 1998, p.87 - 88, 1999/10
no abstracts in English
-point temperatureHiroki, Akihiro*; Yoshida, Masaru; *; Asano, Masaharu; N.Reber*; R.Spohr*; Kubota, Hitoshi*; Katakai, Ryoichi*
Radiat. Eff. Defects Solids, 147, p.165 - 175, 1999/00
no abstracts in English
Yoshida, Masaru; Asano, Masaharu; Suwa, Takeshi; N.Reber*; R.Spohr*; Katakai, Ryoichi*
Advanced Materials, (9), p.757 - 758, 1997/09
Times Cited Count：28 Percentile：98.06(Chemistry, Multidisciplinary)no abstracts in English
Yoshida, Masaru; Asano, Masaharu; Omichi, Hideki; Spohr, R.*; Katakai, Ryoichi*
Radiat. Meas., 28(1-6), p.799 - 810, 1997/00
Times Cited Count：12 Percentile：67.87(Nuclear Science & Technology)no abstracts in English
Yoshida, Masaru; Asano, Masaharu; Safranj, A.; Omichi, Hideki; Spohr, R.*; Vetter, J.*; Katakai, Ryoichi*
Macromolecules, 29(27), p.8987 - 8989, 1996/00
Times Cited Count：53 Percentile：87.39(Polymer Science)no abstracts in English
Yamaki, Tetsuya
no journal, ,
My talk is devoted to the following two topics, both of which include the creation of fluoropolymer-based nanostructures with swift heavy ions mainly from the cyclotron of the Takasaki Ion Accelerators for Advanced Radiation Application. (1) We have prepared the ion-track membranes of poly(vinylidene fluoride) (PVDF), a type of fluoropolymer, by etching out latent tracks of MeV-GeV heavy ions in an alkaline solution. (2) The electrolyte membranes for fuel cell applications have been prepared by the direct grafting of a styrene monomer into the ion tracks in a fluoropolymer substrate, poly(ethylene-co-tetrafluoroethylene) (ETFE) film.
Yamaki, Tetsuya
no journal, ,
We have realized the importance of developing micro/nanofabrication techniques for fluoropolymers in order to further pursue the potential for their future applications. My talk is devoted to our recent research activities on (1) ion-track membranes of poly(vinylidene fluoride) (PVDF) and (2) proton-conductive membranes prepared by ion-track grafting into poly(ethylene-co-tetrafluoroethylene) (ETFE) films. Both of them include the creation of fluoropolymer-based nanostructures with swift heavy ions mainly from the cyclotron of the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA.
Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Asano, Masaharu*; Sawada, Shinichi; Kitamura, Akane; Maekawa, Yasunari; Kay-Obbe, V.*; Severin, D.*; Seidl, T.*; et al.
no journal, ,
Practically, polyvinylidene fluoride (PVDF) has been said to be the only fluoropolymer in which ion tracks can be developed by chemical etching. We thus investigated the possibility of varying the beam parameters and applying the effect of a pre-etching treatment for PVDF ion-track membranes with the goal of achieving enhanced track etching for effective control of the pore size and shape. Our activities also cover all types of fluoropolymers including PVDF. Compared to PVDF, poly(ethylene-
-tetrafluoroethylene) and a series of perfluoropolymers are known to be very stable in highly-concentrated acid or alkaline solutions or at higher temperatures. Although this property might make their ion-track etching very challenging, the ongoing research is expected to allow one to accumulate know-how on methods of chemical etching, which can be generalized for the chemical structures. These will give feedback to a guiding principle for effective ion-track etching in fluoropolymers.
Koshikawa, Hiroshi; Yamamoto, Shunya; Sugimoto, Masaki; Kitamura, Akane; Sawada, Shinichi; Yamaki, Tetsuya
no journal, ,
Chemical etching of polymer films irradiated with heavy ions leads to the formation of ion-track membranes with nanoscale pores in different shapes. Particularly, conically-shaped pores are expected to have a potential to create metallic nanoneedles by combination of vapor-deposition and electroplating methods. In this study, we prepared copper nanoneedles inside the conical pores of polyimide (PI)-based ion-track membranes and investigated their morphology. The PI films were irradiated with 
Ar ions. The irradiated films were etched in a sodium hypochlorite solution at 60
C for 0.5 h, leading to the formation of conical pores with a surface diameter of ca. 500 nm. A very thin Au layer was deposited on this pore side of the ion-track membranes; then, it was used as a cathode for electroplating copper into the pores. After dissolving the PI templates, we obtained the copper needles ca. 500 nm in base diameter and 1.2 m in height on copper plates.
