Imai, Hiroaki

写真a

Affiliation

Faculty of Science and Technology, Department of Applied Chemistry (Yagami)

Position

Professor

Related Websites

External Links

Profile Summary 【 Display / hide

  • 材料化学、バイオミネラリゼーション、無機機能材料、自己組織化プロセス

Career 【 Display / hide

  • 1985.04
    -
    1985.11

    日本酸素株式会社開発本部

  • 1985.11
    -
    1987.12

    工業技術院電子技術総合研究所出向

  • 1988.01
    -
    1992.03

    日本酸素株式会社技術本部

  • 1992.04
    -
    1993.03

    日本酸素株式会社電子機材事業本部

  • 1993.04
    -
    1996.03

    慶應義塾大学(理工学部)助手

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Academic Background 【 Display / hide

  • 1983.03

    Keio University, Faculty of Engineering, 応用化学科

    University, Graduated

  • 1985.03

    Keio University, Graduate School, Division of Engineering, 応用化学専攻

    Graduate School, Completed, Master's course

Academic Degrees 【 Display / hide

  • 工学 , Keio University, 1990.03

 

Books 【 Display / hide

  • Ultraviolet (UV) irradiation

    Imai H., Handbook of Sol-Gel Science and Technology: Processing, Characterization and Applications, 2018.07

     View Summary

    Ultraviolet (UV) photons interact with chemical bonds in systems undergoing sol-gel processing. Generally, UV photons induce electronic excitations in precursors containing organic and inorganic components. In particular, UV irradiation has been used to heat, to create defects, to reduce organics, and to pattern gels. UV-induced densification and crystallization have been observed. Gels containing photo-sensitizers have been studied for patterning applications.

  • Nanoscience Volume 1:Nanostructures through Chemistry

    Yuya Oaki and Hiroaki Imai, The Royal Society of Chemistry, 2013

    Scope: 1-28

  • Mesoscale Chemistry

    Hiroaki Imai, Yuya Oaki, Pan Stanford Publishing. Ltd., 2012

  • 最先端材料システムワンポイントシリーズ「自己組織化と機能材料」

    IMAI HIROAKI, 共立出版, 2012

  • セラミックデータブック 2010/11

    IMAI HIROAKI, 2010

    Scope: 68-72

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Papers 【 Display / hide

  • Micro- and nanometric characterization of the celestite skeleton of acantharian species (Radiolaria, Rhizaria)

    Fujimaki R., Suzuki N., Kimoto K., Nagai Y., Oaki Y., Shimode S., Toyofuku T., Imai H.

    Scientific Reports (Scientific Reports)  12 ( 1 )  2022.12

     View Summary

    We clarified the specific micrometric arrangement and nanometric structure of the radiolarian crystalline spines that are not a simple single crystal. A body of the celestite (SrSO4) skeleton of acantharian Acanthometra cf. multispina (Acanthometridae) composed of 20 radial spines having four blades was characterized using microfocus X-ray computed tomography. The regular arrangement of three types of spines was clarified with the connection of the blades around the root of each spine. The surface of the spines was covered with a chitin-based organic membrane to prevent from dissolution in seawater. In the nanometric scale, the mesocrystalline structure that consists of nanoscale grains having distorted single-crystal nature was revealed using scanning- and transmission electron microscopies, electron diffraction, and Raman spectroscopy. The acantharian skeletons have a crystallographically controlled architecture that is covered with a protective organic membrane. These facts are important for penetrating the nature of biogenic minerals.

  • Ultrastructure of setae of a planktonic diatom, Chaetoceros coarctatus

    Owari Y., Nakamura F., Oaki Y., Tsuda H., Shimode S., Imai H.

    Scientific Reports (Scientific Reports)  12 ( 1 )  2022.12

     View Summary

    Silica frustules of most planktonic diatoms have many shallow holes in which the length (L) is smaller than the width (W). The present study focuses on a silica ultrastructure of setae of a planktonic diatom having deep (L/W > 1) holes. Here, we characterized microscopically patterned nanoholes on the silica walls of thick, robust, and hollow setae of a colony of Chaetoceros coarctatus. Basically, tetragonal poroid arrangements with and without a costa pattern are observed on the inner and outer surfaces, respectively, for three kinds of curving hollow setae attached to the anterior, intercalary, and posterior parts of the colony. The seta structures including specific poroid arrangements and continuity of deep nanoholes depend on the location. The deep nanoholes ∼90 nm wide are elongated from 150 to 1500 nm (L/W ∼17) with an increase in the wall thickness of the polygonal tubes of the setae. The inside poroid array, with a period of 190 nm in the extension direction of setae, is lined by parallel plates of the costae. However, the poroid arrangement on the outer surface is disordered, with several holes obstructed with increasing wall thickness of the posterior terminal setae. According to the movement of a colony in a fluid microchannel, the thick curving terminal setae is suggested to involve attitude control and mechanical protection. Using an optical simulation, the patterned deep through-holes on the intercalary setae were suggested to contribute anti-reflection of blue light in the wavelength range of 400 to 500 nm for the promotion of photosynthesis in seawater.

  • Performance Predictors for Organic Cathodes of Lithium-Ion Battery

    Sakano K., Igarashi Y., Imai H., Miyakawa S., Saito T., Takayanagi Y., Nishiyama K., Oaki Y.

    ACS Applied Energy Materials (ACS Applied Energy Materials)  5 ( 2 ) 2074 - 2082 2022.02

     View Summary

    Organic cathodes for lithium-ion batteries are one of the most promising and significant materials toward a sustainable society. The molecular design is a key to achieve superior performances beyond inorganic cathodes. The present work shows predictors of the reaction potential, specific capacity, and ideal energy density for organic cathodes. Straightforward prediction models of the performance were constructed by a combination of machine learning and chemical insight, namely, sparse modeling for small data (SpM-S), on a small data set as training data found in the literature. The prediction accuracy was validated using different literature data. The predictors can be applied to explore high-performance organic cathodes in a wide search space efficiently. Moreover, SpM-S afforded straightforward, interpretable, and generalizable prediction models compared to other machine-learning algorithms. The small-data-driven methodology can be applied for further exploration of materials, enhancement of performances, and optimization of processes.

  • Designed nanostructures created via physicochemical switching of the growth mode between single crystals and mesocrystals†

    Kanazawa S., Oaki Y., Imai H.

    Nanoscale Advances (Nanoscale Advances)  4 ( 6 ) 1538 - 1544 2022.02

     View Summary

    Most biominerals are composed of mesocrystals, in which individual nanoparticle building units have a defined long-range order on the atomic scale in at least one direction. Although the crystal size and orientation of the mesostructures are spatially designed in biological architectures, it has been difficult to achieve adequate control of the crystal growth to produce modulated mesostructures in artificial aqueous systems. Here, we propose a simple physicochemical approach for the spatial design of nanostructures using an aqueous solution system. The ordered arrays of oriented fluorapatite (FA) rods similar to tooth enamel are produced on a polymer substrate in a supersaturated solution. We succeeded in reversible switching of the growth mode of FA between single-crystalline rods and mesocrystalline grains through the disturbance of the solution. The primary crystal size was tuned between micrometric rods ∼0.5 μm wide and >5 μm long and nanoscale grains ∼10 nm wide and 50 nm long without a drastic change in the c direction. Hierarchical architectures consisting of iso-oriented FA microrods and nanograins were constructed via temporal control of the crystal growth mode by switching a physicochemical parameter, such as the degree of supersaturation at the growth front.

  • Electroless nickel plating on a biomineral-based sponge structure

    Takeoka H., Seike M., Nakamura Y., Imai H., Oaki Y., Fujii S.

    Materials Advances (Materials Advances)  3 ( 2 ) 931 - 936 2022.01

     View Summary

    A 3-dimensional polypyrrole-palladium nanocomposite material was prepared by transferring a sponge structure of a sea urchin spine via chemical oxidative polymerization. The nanocomposite material was successfully coated with nickel, maintaining the 3-dimensional sponge structure by electroless plating in an aqueous medium.

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Papers, etc., Registered in KOARA 【 Display / hide

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Presentations 【 Display / hide

  • ゾルゲル法による多孔質スピネル型MgMn2O4の合成およびマグネシウム二次電池への応用

    Hiroaki Imai

    The Ceramic Society of Japan Annual Meeting 2019 (Kogakuin University (Shinjuku Campus)) , 

    2019.03

    Oral presentation (general)

  • ドライおよびウェットな低温環境におけるカルサイトナノ結晶の開裂と粒成長

    Hiroaki Imai

    The Ceramic Society of Japan Annual Meeting 2019 (Kogakuin University (Shinjuku Campus)) , 

    2019.03

    Oral presentation (general)

  • カルサイトナノロッドの単層集積によるナノスケールパターンの形成

    Hiroaki Imai

    The Ceramic Society of Japan Annual Meeting 2019 (Kogakuin University (Shinjuku Campus)) , 

    2019.03

    Oral presentation (general)

  • Fe3O4ナノキューブ単層配列体の作製およびその磁気特性の評価

    Hiroaki Imai

    The Ceramic Society of Japan Annual Meeting 2019 (Kogakuin University (Shinjuku Campus)) , 

    2019.03

    Oral presentation (general)

  • 炭酸含有水酸アパタイトナノ粒子の合成とマクロ造形への応用

    Hiroaki Imai

    The Ceramic Society of Japan Annual Meeting 2019 (Kogakuin University (Shinjuku Campus)) , 

    2019.03

    Oral presentation (general)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • 大規模かつ階層的なメソクリスタル構造の構築と無機・有機融合機能の開拓

    2021.04
    -
    2025.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

  • デザインされた異方性ナノブロックによる秩序配列マテリアルの構築と機能開拓

    2016.04
    -
    2020.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (A) , Principal investigator

  • Clarification of crystal growth through oriented attachment and its application for development of nanomaterials

    2015.04
    -
    2018.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Challenging Exploratory Research, Principal investigator

Works 【 Display / hide

  • 実験化学講座「無機化合物」

    IMAI HIROAKI

    2005.03
    -
    Present

    Other, Joint

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    固体化学・無機材料化学の研究・教育に重要な各種の実験技術の解説書。

  • セラミックス大学

    IMAI HIROAKI

    2000.05
    -
    2006.10

    Other, Joint

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    年間7〜8回の講義を通して、セラミックスの基礎と応用を社会人、大学生を問わず分かりやすく解説する教育講座の企画および講師を担当。

Awards 【 Display / hide

  • 日本結晶成長学会第32回論文賞

    今井宏明, 2015.10, 日本結晶成長学会, メソ結晶におけるねじれ形態発現機構の解明とその制御

  • 第 68 回(平成 25 年度)日本セラミックス協会賞学術賞

    今井宏明, 2013.11, 公益社団法人日本セラミックス協会, バイオミネラルに着想を得たセラミックス合成プロセスの深化と応用

 

Courses Taught 【 Display / hide

  • SEMINAR IN APPLIED CHEMISTRY

    2022

  • SCIENCE OF SELF-ASSEMBLY

    2022

  • NANO SCALE SCIENCE JOINT SEMINAR

    2022

  • MATERIAL DESIGN SCIENCE JOINT SEMINAR

    2022

  • LABORATORIES IN APPLIED CHEMISTRY C

    2022

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Social Activities 【 Display / hide

  • 全国高校化学グランプリ2012・2次選考特別講演・公益社団法人日本化学会

    2012.08

     View Summary

    参加者:中高生約80名

  • ひらめき☆ときめきサイエンス~ようこそ大学の研究室へ~KAKENHI:「生き物による結晶づくりを学び・まねしよう」講義と実験

    2011.08

     View Summary

    参加者:中高生19名
    於:慶応義塾大学矢上キャンパス

  • 全国高校化学グランプリ2011 2次選考特別講演

    2011.08

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    主催:「夢・化学-21」委員会
    参加者:中高生約80名
    於:慶應義塾大学日吉・矢上キャンパス

  • 独立行政法人産業技術総合研究所

    2008.05
    -
    Present
  • 独立行政法人物質・材料研究機構

    2001.05
    -
    2005.03

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Memberships in Academic Societies 【 Display / hide

  • 日本セラミックス協会編集委員会, 

    2010.04
    -
    2018.06
  • 日本セラミックス協会行事企画委員会, 

    2007.04
    -
    2009.03
  • 日本化学会欧文誌編集員会, 

    2005.04
    -
    2010.03
  • 日本ゾルゲル学会, 

    2003.07
    -
    Present
  • 日本結晶成長学会, 

    2000.04
    -
    Present

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Committee Experiences 【 Display / hide

  • 2018.06
    -
    Present

    運営委員会委員長, 日本セラミックス協会

  • 2010.04
    -
    2018.06

    Editor, 日本セラミックス協会編集委員会

  • 2008.05
    -
    2010.04

    客員研究官, 独立行政法人産業技術総合研究所

  • 2007.04
    -
    2009.03

    Committee Chair, 日本セラミックス協会行事企画委員会

  • 2005.04
    -
    2010.03

    Editor, 日本化学会欧文誌編集員会

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