ISIR

The Institute of Scientific and Industrial Research, Osaka University

大阪大学
産業科学研究所

LAST UPDATE 2017/02/26

  • 研究者氏名
    Researcher Name

    誉田義英　Yoshihide HONDA
    准教授　Associate Professor

  • 所属
    Professional Affiliation

    大阪大学産業科学研究所
    The Institute of Scientific and Industrial Research, Osaka University

    量子ビーム科学研究施設
    Research Laboratory for Quantum Beam Science

  • 研究キーワード
    Research Keywords

    陽電子消滅分光
    フッ素系高分子
    粘土鉱物
    電子加速器
    Positron Annihilation Spectroscopy
    Perfluorinated polymers
    Cray Minerals
    Electron Linear Accelerator
研究テーマ
Research Subject
陽電子消滅法による材料評価
Evaluation of materials using positron annihilation spectroscopy

研究の背景 Background

陽電子や電子・陽電子対の3重項状態であるオルソポジトロニウムの物質中での寿命を用いて、通常はそれに含まれる欠陥や相転移に伴う自由体積の変化等が調べられています。しかし多くの機能性材料では官能基や不純物の存在により陽電子の消滅過程もその影響を受けます。これを逆手に取ることでその機能変化を高感度に調べることが可能になります。

The lifetimes of a positron and an ortho-positronium (o-Ps), which is a triplet of electron-positron bound state, in materials are used, in general, to get the information of defects or free volume with high sensitivity. However, in many functional materials or impurity-included ones, the annihilation process of positron/o-Ps lifetime would be greatly influenced by the presence of local electric field due to the functional groups and the impurities, implying that a subtle change relating to them can be detected with positron.

研究の目標 Outcome

燃料電池の構成要素の１つである高分子電解質膜の、特にラジカルに関連する劣化評価を行っています。また原発事故に係る飛散した放射性物質（RI）の除染方法を見出すため、土中鉱物の種類とRI捕集効率との関係や効率の良いキレート材の探索等を陽電子消滅法を用いて調べています。

The degradation process of polymer electrolyte membranes due to radicals in fuel cell has been investigated. Also, to find a proper manner to separate the fallout due to nuclear power plant accident, the relationship between structure difference and the trapping efficiency of radioisotopes in clay minerals of soil and the effective decontamination material are investigated mainly using positron annihilation spectroscopy (PAS).

研究図Research Figure

Fig.1. Deduced localization of orthopositronium by changing temperature and humidity. Fig.2. Localization of HO* in hydrophilic site deduced by pulse radiolysis (upper) and the destructions due to HO* and H* observed by PAS (lower). Fig.3.Doppler broadened spectra for different clay minerals (upper) and extraction rate of Cs (lower).

文献 / Publications

J. Power Sources, 196, 9856 (2011). Material Sci. Forum, 733, 53, (2012). J. Phys: Conf. Ser., 443, 012052, (2013).

研究者HP