コイズミ　サトシ
小泉　智教授
Satoshi KOIZUMI

■研究者基本情報

組織

  • 工学部
  • 理工学研究科（博士前期課程） 量子線科学専攻
  • 理工学研究科（博士後期課程） 量子線科学専攻
  • 応用理工学野 ビームライン科学領域

研究分野

  • ナノテク・材料, 高分子材料, 機能材料 ソフトマター

研究キーワード

  • 中性子散乱法の開発
  • 中性子産業利用
  • 階層構造と機能
  • ソフトマター物性
  • 高分子ゲル、高分子電解質, 高分子ブレンド、ゴム、繊維
  • タンパク質 構造生物学

学位

  • 1995年05月　博士（工学）（京都大学）
  • 1990年03月　修士（工学）（京都大学）

学歴

  • 1993年, 京都大学, 工学研究科
  • 1993年, 京都大学, Graduate School, Division of Engineering
  • 1990年, 京都大学, 工学研究科
  • 1990年, 京都大学, Graduate School, Division of Engineering
  • 1988年, 京都大学, 工学部
  • 1988年, 京都大学, Faculty of Engineering

経歴

  • 2011年10月, 茨城大学 工学部 共通講座, 教授
  • 1993年04月 - 2011年09月, 国立研究開発法人日本原子力研究開発機構

外部リンク

研究者からのメッセージ

  • (研究者からのメッセージ)

    工学部高分子化学科に学び、透過型電子顕微鏡によるジブロック共重合体のミクロ相分離構造の研究で学位を取得.　その後、原子力機構にて中性子小角散乱法および散乱装置の開発に従事、2011年より茨城大学工学部で基礎物理や高分子材料の教育に関わる. 担当する授業科目は、統計力学、熱力学、量子力学、高分子材料学、放射線科学など.　2023年より総合科学研究機構　中性子産業利用推進センター（副センター長）を兼務して中性子産業利用を推進

■研究活動情報

論文

  • Development of nanosized graphene material for neutron intensity enhancement below cold neutron energy
    Makoto Teshigawara; Yujiro Ikeda; Kazuo Muramatsu; Koichi Sutani; Masafumi Fukuzumi; Yohei Noda; Satoshi Koizumi; Koichi Saruta; Yoshie Otake, We have been developing nanosized graphene, called graphene flower, as a material that induces coherent scattering very cold neutrons. Previous experiments have found that the seed part of the graphene flower is more effective than the petal part in increasing the coherent scattering. Based on these results, we found that further modification of the graphene flower to increase the seed portion increased the total cross-section, although it did not reach the level of nanodiamonds., SAGE Publications
    Journal of Neutron Research, 2024年04月25日
  • Effects of Functional Graft Polymers on Phase Separation and Ion-Channel Structures in Anion Exchange Membranes Analyzed by SANS Partial Scattering Function
    Kimio Yoshimura; Akihiro Hiroki; Aurel Radulescu; Yohei Noda; Satoshi Koizumi; Yue Zhao; Yasunari Maekawa, American Chemical Society (ACS)
    Macromolecules, 2024年02月21日
  • Water distribution in human hair microstructure elucidated by spin contrast variation small-angle neutron scattering
    Yohei Noda; Satoshi Koizumi; Tomoki Maeda; Takumi Inada; Aya Ishihara, Dynamic nuclear polarization (DNP) is effective for controlling the neutron scattering length of protons and can be utilized for contrast variation in small-angle neutron scattering (SANS). Using the TEMPOL solution soaking method as electron spin doping, the DNP–SANS technique was applied to human hair fiber for the first time. For dry and D2O-swollen hair samples, a drastic change in the SANS profile was observed at high polarization conditions (|P H P N| ∼ 60%, where P H and P N are the proton and neutron spin polarization, respectively). The SANS profile as a function of the magnitude of the scattering vector, q, was composed of a low-q upturn, a middle-q oscillation and a high-q flat region. The low-q upturn was assumed to be a combination of two power-law functions, q −4 due to a large structure interface (Porod's law) and q −2 due to random coil. The middle-q oscillation was well reproduced by numerical calculation based on the structure model of intermediate filaments (IFs) as proposed by Er Rafik et al. [Biophys. J. (2004), 86, 3893–3904]: one pair of keratin coiled-coils is located at the center and surrounded by seven pairs of keratin coiled-coils located in a circle (called the `7 + 1' model), and a collection of IFs is arranged in a quasi-hexagonal manner. For the observed SANS profiles for different P H P N, the IF term contribution maintained a constant q-dependent profile, despite significant changes in intensity. This indicates that the macrofibril is composed of two domains (keratin coiled-coils and matrix). In addition, D2O swelling enhanced the IF term intensity and shifted the polarization-dependent local minimum to higher P H P N. This behavior was reproduced by contrast factor calculation based on the two-domain model. Scattering length densities of keratin coiled-coil and surrounding matrix domains were calculated by use of the known amino acid composition, considering the hydrogen–deuterium exchange reaction during soaking with D2O solution of TEMPOL. As a result, it was found that for keratin coiled-coil domains, about 40% of the peptide backbone amide NH protons were replaced with deuterons. This means that 68% of the α-helix domain is rigid, but the rest is flexible to allow dynamic dissociation of the hydrogen bond. Furthermore, the local mass density of each domain was precisely evaluated. The obtained data are expected to be a guide for further detailed investigation of keratin and keratin-associated protein distribution. This approach is expected to be applied to a wide variety of bio-derived materials, which are water absorbing in general., International Union of Crystallography (IUCr)
    Journal of Applied Crystallography, 2023年06月30日
  • Microscopic Depictions of Vanishing Shampoo Foam Examined by Time-of-Flight Small-Angle Neutron Scattering
    Satoshi Koizumi; Yohei Noda; Takumi Inada; Tomoki Maeda; Shiho Yada; Tomokazu Yoshimura; Hiroshi Shimosegawa; Hiroya Fujita; Munehiro Yamada; Yukako Matsue, A novel surfactant of N–dodecanoyl–N–(2-hydroxyethyl)–β–alanine (coded as C12–EtOH–βAla) was synthesized by modifying the methyl group of N–dodecanoyl–N–methyl–β–alanine (coded as C12–Me–βAla). Amino-acid-type surfactants (C12–EtOH–βAla and C12–Me–βAla) are more healthy and environmentally friendly compared to sodium dodecyl sulfate (SDS). To investigate the microstructures of these new surfactants, we employed a method of time-of-flight small-angle neutron scattering (TOF SANS) at a pulsed neutron source, Tokai Japan (J–PARC). The advances in TOF SANS enable simultaneous multiscale observations without changing the detector positions, which is usually necessary for SANS at the reactor or small-angle X-ray scattering. We performed in situ and real-time observations of microstructures of collapsing shampoo foam covering over a wide range of length scales from 100 to 0.1 nm. After starting an air pump, we obtained time-resolved SANS from smaller wave number, small-angle scattering attributed to (1) a single bimolecular layer with a disk shape, (2) micelles in a bimolecular layer, and (3) incoherent scattering due to the hydrogen atoms of surfactants. The micelle in the foam film was the same size as the micelle found in the solution before foaming. The film thickness (~27 nm) was stable for a long time (<3600 s), and we simultaneously found a Newton black film of 6 nm thickness at a long time limit (~1000 s). The incoherent scattering obtained with different contrasts using protonated and deuterated water was crucial to determining the water content in the foam film, which was about 10~5 wt%., MDPI AG
    Quantum Beam Science, 2023年01月29日
  • A long side chain imidazolium-based graft-type anion-exchange membrane: novel electrolyte and alkaline-durable properties and structural elucidation using SANS contrast variation.
    Yue Zhao; Kimio Yoshimura; Ahmed Mohamed Ahmed Mahmoud; Hwan-Chul Yu; Shun Okushima; Akihiro Hiroki; Yoshihiro Kishiyama; Hideyuki Shishitani; Susumu Yamaguchi; Hirohisa Tanaka; Yohei Noda; Satoshi Koizumi; Aurel Radulescu; Yasunari Maekawa, Newly designed styrylimidazolium-based grafted anion-exchange membranes (StIm-AEMs), in which imidazolium ionic groups are attached to styrene at the far side from the graft chains, were prepared by radiation-induced graft polymerization of p-(2-imidazoliumyl) styrene onto poly(ethylene-co-tetrafluoloethylene) (ETFE) films, followed by N-alkylation and ion-exchange reactions. StIm-AEM having an ion exchange capacity (IEC) of 0.54 mmol g-1 with a grafting degree (GD) of ∼18%, possesses practical conductivity (>50 mS cm-1) even with a very low water uptake (∼10%) and high stability over 600 h in a 1 M KOH solution at 80 °C. There exists a critical IEC (IECc) in the range of 0.7-0.8 mmol g-1 over which the membrane showed high water uptake, which resulted in pronounced susceptibility to hydrolysis. Using small-angle neutron scattering technique with a contrast variation method, we found the hydrophilic phase in StIm-AEMs with IECs lower and higher than IECc shows "reverse-micelles" with water domains dispersed in the polymer matrix and "micelles" with graft polymer aggregates dispersed in the water matrix, respectively. The further analysis of micelle structures using the hard-sphere liquid model and Porod limit analysis reveals that the interfacial structures of ionic groups are essential for the electrochemical properties and durability of StIm-AEMs. In addition, StIm-AEM with an IEC of 0.95 mmol g-1 and the maximum power density of 80 mW cm-2 in the hydrazine hydrate fuel cell test, exhibited long-term durability under constant current (8.0 mA) up to 455 h, which, thus far, is the best durability at 80 °C for platinum-free alkaline-type liquid fuel cells.
    Soft matter, 2020年09月16日
  • 生物が織り成す繊維:－マイクロバイアルセルロースの神秘－
    小泉 智, 社団法人 繊維学会
    繊維学会誌, 2020年, ［査読有り］
  • Hierarchical structure in microbial cellulose: what happens during the drying process.
    Yue Zhao; Satoshi Koizumi; Daisuke Yamaguchi; Tetsuo Kondo, We present a time-resolved investigation of the natural drying process of microbial cellulose (MC) by means of simultaneous small-angle neutron scattering (SANS), intermediate-angle neutron scattering (IANS) and weighing techniques. SANS was used to elucidate the microscopic structure of the MC sample. The coherent scattering length density of the water penetrating amorphous domains varied with time during the drying process to give a tunable scattering contrast to the water-resistant cellulose crystallites, thus the contrast variation was automatically performed by simply drying. IANS and weighing techniques were used to follow the macroscopic structural changes of the sample, i.e., the composition variation and the loss of the water. Thus, both the structure and composition changes during the whole drying process were resolved. In particular, the quantitative crosscheck of composition variation by IANS and weighing provides a full description of the drying process. Our results show that: i) The natural drying process could be divided into three time regions: a 3-dimensional shrinkage in region I, a 1-dimensional shrinkage along the thickness of the sample in region II, and completion in region III; ii) the further crystallization and aggregation of the cellulose fibrils are observed in both the rapid drying and natural drying methods, and the rapid drying even induces obvious structural changes in the length scale of 7-125 nm; iii) the amount of "bound water", which is an extremely thin layer of water surrounding the surfaces of cellulose fibrils, was estimated to be ∼ 0.35 wt% by the weighing measurement and was verified by the quantitative analysis of SANS results.
    The European physical journal. E, Soft matter, 2014年12月
  • Crystal morphology-dependent graft polymerization in poly(ether ether ketone) films
    Hasegawa Shin; Takahashi Shuichi; Iwase Hiroki; Koizumi Satoshi; Ohnuma Masato; Maekawa Yasunari
    POLYMER, 2013年05月, ［査読有り］
  • Nanoscale structures of radiation-grafted polymer electrolyte membranes investigated via a small-angle neutron scattering technique
    Sawada Shin-ichi; Yamaguchi Daisuke; Putra Ananda; KOIZUMI Satoshi; MAEKAWA Yasunari, Nature Publishing Group
    Polymer journal, 2013年, ［査読有り］
  • Hierarchical Structure Analysis of Graft-Type Polymer Electrolyte,Membranes Consisting of Cross-Linked Polytetrafluoroethylene by,Small-Angle Scattering in a Wide‑Q Range
    Hiroki Iwase; Shin-ichi Sawada; Tetsuya Yamaki; Satoshi Koizumi; Masato Ohnuma; Yasunari Maekawa
    Macromolecules, 2012年, ［査読有り］
  • Preirradiation Graft Polymerization of Styrene in a Poly(tetrafluoroethylene) Film Investigated by Time-Resolved Small-Angle Neutron Scattering
    Hiroki Iwase; Shin-ichi Sawada; Tetsuya Yamaki; Yasunari Maekawa; Satoshi Koizumi
    INTERNATIONAL JOURNAL OF POLYMER SCIENCE, 2011年, ［査読有り］
  • Mesoscale spatial distribution of electron spins studied by time-resolved small-angle and ultrasmall-angle neutron scattering with dynamic nuclear polarization: a case of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) doped in high-density polyethylene.
    Takayuki Kumada; Yohei Noda; Satoshi Koizumi; Takeji Hashimoto, We carried out time-resolved small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) studies of dynamically polarized high-density polyethylene (HDPE) doped with 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) persistent free radicals. We observed a remarkable enhancement of the scattering intensity shortly after a switching of microwave frequency from positive (negative) to negative (positive) dynamic nuclear polarization (DNP). The enhancement was found to be due to spatially heterogeneous proton-spin polarization generated as a result of heterogeneously distributed TEMPO in the HDPE sample. The spatial fluctuation of the polarization ranged up to the length-scale of > or = 100 nm. This result strongly suggests that the TEMPO free radicals are localized more in nonfibrils but less in fibrils of HDPE. In this way, we propose that the time-resolved DNP-SANS and DNP-USANS be general techniques to determine mesoscale spatial distribution of electron spins in dielectric materials.
    The Journal of chemical physics, 2010年08月07日

MISC

書籍等出版物

講演・口頭発表等

  • In-situ Observation of Polymer Electrolyte Fuel Cell (PEFC) by Neutron Small-Angle Scattering with Contrast Variation by Using Deuterium Gas　　　　　　　　　　　　　　　
    SAS2012 (Sydney), 2012年11月22日, ［招待有り］
  • In-situ Observation of Operating Polymer Electrolyte Fuel Cell (PEFC) by Neutron Small-Angle Scattering - Contrast Variation by Using Deuterium Gas -　　　　　　　　　　　　　　　
    JCNS Workshop 2012 (Trends and Perspectives in Neutron Scattering for Soft Matter and Biophysics), 2012年10月08日

担当経験のある科目（授業）

  • 〔主要な業績〕量子力学　　　　　　　　　　　　　　　
    2012年04月 - 2019年08月
    茨城大学工学部 電気電子学科
  • 高分子材料学　　　　　　　　　　　　　　　
    2017年04月
    茨城大学工学部
  • 基礎物理学（統計力学・熱力学）　　　　　　　　　　　　　　　
    2011年04月
    茨城大学工学部
  • 放射線科学　　　　　　　　　　　　　　　

所属学協会

  • 2010年10月, 日本ゴム協会
  • 2010年10月, 繊維学会
  • 1997年04月, 日本中性子科学会
  • 1993年04月, 高分子学会

共同研究・競争的資金等の研究課題

産業財産権

  • 特開2022-174767, 特願2021-080712, 中性子イメージング装置、及び中性子イメージング方法
    小泉 智, 能田 洋平
  • 特許第7166637号, JP2018025943, 中性子光学素子及び中性子源
    小泉 智, 能田 洋平
  • 特許第7061765号, 特開2019-015638, 特願2017-133999, 薄膜測定方法、及び測定装置
    岡 隆史, 一和多 広子, 小泉 智
  • 特許第6868238号, 特開2018-071987, 特願2016-207966, 動的水素核スピン偏極実験用高分子複合材料及びその作製方法、並びに、動的水素核スピン偏極コントラスト変調中性子散乱実験用高分子複合材料
    増井 友美, 能田 洋平, 小泉 智
  • 特開2019-015638, 特願2017-133999, 薄膜測定方法、薄膜測定キット、及び測定装置
    岡 隆史, 一和多 広子, 小泉 智
  • WO2019-017233, JP2018025943, 中性子光学素子及び中性子源
    小泉 智, 能田 洋平
  • 特開2018-071987, 特願2016-207966, 動的水素核スピン偏極実験用高分子複合材料及びその作製方法、並びに、動的水素核スピン偏極コントラスト変調中性子散乱実験用高分子複合材料
    増井 友美, 能田 洋平, 小泉 智