研究者データベース

研究者情報

マスター

アカウント(マスター)

  • 氏名

    磯野 拓也(イソノ タクヤ), イソノ タクヤ

所属(マスター)

  • 工学研究院 応用化学部門 分子機能化学分野

所属(マスター)

  • 工学研究院 応用化学部門 分子機能化学分野

独自項目

syllabus

  • 2020, 応用生物化学A(機能性高分子特論), Applied Biochemistry A (Advanced Functional Polymer), 修士課程, 総合化学院, 高分子合成, 精密重合,リビング重合,ラジカル重合,カチオン重合,アニオン重合,配位重合、機能性高分子,高分子構造,高分子設計, 高分子溶液, 相分離挙動
  • 2020, 応用化学学生実験Ⅴ, Applied Chemistry Laboratory Ⅴ, 学士課程, 工学部, 有機化学、高分子化学、安全教育、基礎実験、合成実験
  • 2020, 英語演習, English Seminar, 学士課程, 全学教育, 英語,化学,工学
  • 2020, 高分子化学Ⅰ, Polymer Chemistry I, 学士課程, 工学部, 高分子・分子量・分子量分散度・逐次重合・連鎖重合・熱可塑性樹脂・熱硬化性樹脂
  • 2020, 化学英語, English for Chemistry, 学士課程, 工学部, 化学,英語,単語,表記法

researchmap

プロフィール情報

学位

  • 博士(工学)(北海道大学)

プロフィール情報

  • 磯野, イソノ
  • 拓也, タクヤ
  • ID各種

    201401071919057656

対象リソース

業績リスト

研究キーワード

  • 生分解性高分子   糖鎖高分子   ミクロ相分離   自己組織化   有機分子触媒   ブロックコポリマー   特殊構造高分子   リビング重合   高分子合成   

研究分野

  • ナノテク・材料 / 高分子材料
  • ナノテク・材料 / 高分子化学

経歴

  • 2021年04月 - 現在 北海道大学 大学院工学研究院 准教授
  • 2015年10月 - 現在 北海道大学 工学研究院 助教
  • 2014年05月 - 2015年09月 北海道大学 工学研究院 特任助教
  • 2014年04月 - 2014年04月 北海道大学 学術振興会特別研究員PD
  • 2012年04月 - 2014年03月 北海道大学 学術振興会特別研究員DC1

学歴

  • 2011年10月 - 2014年03月   北海道大学   大学院総合化学院   博士後期課程
  • 2010年04月 - 2011年09月   北海道大学   大学院総合化学院   修士課程
  • 2008年04月 - 2010年03月   苫小牧工業高等専門学校   専攻科   環境システム工学専攻

受賞

  • 2021年03月 北海道大学大学院工学研究院 若手教員奨励賞
  • 2020年10月 北海道大学 部局横断型若手研究助成事業 奨励賞
  • 2020年03月 高分子学会 高分子研究奨励賞
     置換エポキシドの精密重合を基盤とした機能性ポリエーテルの合成
  • 2019年06月 CUPAL優秀活動賞
     
    受賞者: 磯野 拓也
  • 2018年09月 GISAS2018 Best Poster Award
     
    受賞者: 磯野 拓也
  • 2015年12月 井上科学振興財団 第32回井上研究奨励賞
     脂肪族ポリエステルを基盤とした特殊構造ブロック共重合体の合成とバルク特性に関する研究 
    受賞者: 磯野 拓也
  • 2013年09月 第20回国際先端錯体工学研究会 SPACC-20 Poster Award
     
    受賞者: 磯野 拓也
  • 2012年11月 Korea-Japan Joint Symposium 2012: Future Perspectives of Functional Polymers KJJS The Best Poster Award
     
    受賞者: 磯野 拓也
  • 2012年02月 高分子学会 第46回高分子学会北海道支部研究発表会優秀ポスター賞
     
    受賞者: 磯野 拓也
  • 2011年11月 Japan-Korea Joint Symposium 2011: Advanced Soft Nanomaterials JKJS2011 Incentive Poster Award
     
    受賞者: 磯野 拓也
  • 2010年08月 高分子学会 2010年度北海道高分子若手研究会最優秀発表賞
     
    受賞者: 磯野 拓也
  • 2009年12月 日本学生支援機構 平成21年度日本学生支援機構優秀学生顕彰 学術分野 奨励賞
     
    受賞者: 磯野 拓也
  • 2009年09月 日本化学会 平成21年度夏季日本化学会北海道支部優秀講演賞
     
    受賞者: 磯野 拓也
  • 2009年08月 高分子学会 2009年度北海道高分子若手研究会優秀発表賞
     
    受賞者: 磯野 拓也
  • 2008年03月 日本化学会 平成19年度日本化学会北海道支部賞
     
    受賞者: 磯野 拓也

論文

  • Kodai Watanabe, Noya Kaizawa, Brian J. Ree, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Angewandte Chemie 2021年08月09日
  • Dai-Hua Jiang, Brian J. Ree, Takuya Isono, Xiao-Chao Xia, Li-Che Hsu, Saburo Kobayashi, Kuan Hoon Ngoi, Wei-Cheng Chen, Chih-Chun Jao, Loganathan Veeramuthu, Toshifumi Satoh, Shih Huang Tung, Chi-Ching Kuo
    Chemical Engineering Journal 418 129421 - 129421 2021年08月
  • Satoshi Katsuhara, Yasuko Takagi, Naoki Sunagawa, Kiyohiko Igarashi, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    ACS Sustainable Chemistry & Engineering 9 29 9779 - 9788 2021年07月26日
  • Brian J. Ree, Yusuke Satoh, Takuya Isono, Toshifumi Satoh
    ACS Macro Letters 2021年06月14日
  • Tomohisa Watanabe, Satoru Chimura, Yubo Wang, Tomoko Ono, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Daichi Ida, Takuya Yamamoto
    Langmuir 2021年05月28日
  • Xiaochao Xia, Ryota Suzuki, Kaoru Takojima, Dai-Hua Jiang, Takuya Isono, Toshifumi Satoh
    ACS Catalysis 5999 - 6009 2021年05月21日
  • Brian J. Ree, Yusuke Satoh, Takuya Isono, Toshifumi Satoh
    Macromolecules 2021年04月19日
  • Takuya Isono
    POLYMER JOURNAL 2021年04月 
    This focused review provides an overview of our recent work and related research regarding the precise anionic ring-opening polymerization (AROP) of substituted epoxides, including alkylene oxides, glycidyl ethers, and glycidyl amines, using t-Bu-P-4 as the phosphazene base catalyst to produce functional polyethers, such as homopolymers, block copolymers (BCPs), and topologically unique polymers. First, the fundamental aspects and applicable monomer scope of the t-Bu-P-4-catalyzed AROP are discussed. Subsequently, the applications of the AROP system for synthesizing functional materials and architectural polymers are presented.
  • Brian J. Ree, Yoshinobu Mato, Li Xiang, Jehan Kim, Takuya Isono, Toshifumi Satoh
    POLYMER CHEMISTRY 12 5 744 - 758 2021年02月 
    Here we report the first quantitative investigation of nanoscale film morphologies of a cage-shaped poly(epsilon-caprolactone) (cg-PCL9k) and its counterparts in star, cyclic, and linear topologies (st-PCL9k, cy-PCL6k, and l-PCL6k) with consideration of topological influence through synchrotron grazing incidence X-ray scattering analysis. The folded crystalline layer thickness l(c) is found to be in the increasing order of: st-PCL9k < l-PCL6k < cy-PCL6k < cg-PCL9k. Additional structural parameters, such as lamellar orientation, crystallinity, and orientation of orthorhombic lattice in nanoscale film, exhibit intricate dependencies on their molecular topologies and steric influences from the molecular joints and end groups. Nevertheless, all topological PCLs form lamellar structures based on the orthorhombic crystal lattice in nanoscale films. In addition, crystallization temperature T-c and crystal melting temperature T-m of all PCLs in bulk are highly dependent on the molecular topology; both T-c and T-m follow the same increasing trend of: st-PCL9k < l-PCL6k < cy-PCL6k < cg-PCL9k. Phase transition characteristics such as heat of fusion and crystallinity in bulk state, and thermal stability also depend upon the topological and steric influences.
  • Brian J. Ree, Yusuke Satoh, Takuya Isono, Toshifumi Satoh
    Polymer Chemistry 2021年 

    Three-armed cage block copolymers composed of immiscible blocks in near equivalent volume fractions formed topologically controlled sub-10 nm cylindrical and lamellar nanostructures in nanoscale films.

  • Mahmoud M. Abd Elwakil, Tianle Gao, Takuya Isono, Yusuke Sato, Yaser H. A. Elewa, Toshifumi Satoh, Hideyoshi Harashima
    Materials Horizons 2021年
  • Li-Che Hsu, Takuya Isono, Yan-Cheng Lin, Saburo Kobayashi, Yun-Chi Chiang, Dai-Hua Jiang, Chih-Chien Hung, Ender Ercan, Wei-Chen Yang, Hui-Ching Hsieh, Kenji Tajima, Toshifumi Satoh, Wen-Chang Chen
    ACS APPLIED MATERIALS & INTERFACES 13 2 2932 - 2943 2021年01月 
    The mechanical properties and structural design flexibility of charge-trapping polymer electrets have led to their widespread use in organic field-effect transistor (OFET) memories. For example, in the electrets of polyfluorene-based conjugated/insulating block copolymers (BCPs), the confined fiberlike polyfluorene nanostructures in the insulating polymer matrix act as effective hole-trapping sites, leading to controllable memory performance through the design of BCPs. However, few studies have reported intrinsically stretchable charge-trapping materials and their memory device applications, and a practical method to correlate the thin-film morphology of BCP electrets with their charge-trapping ability has not yet been developed. In this study, a series of new conjugated/insulating BCPs, poly(9,9-di-n-hexyl-2,7-fluorene)-block-poly(delta-decanolactone)s (PF-b-PDLx, x = 1-3), as stretchable hole-trapping materials are reported. The linear and branched PDL blocks with comparable molecular weights were used to investigate the effect of polymer architecture on morphology and device performance. Moreover, the coverage area of the polyfluorene nanofibers on the BCP films was extracted from atomic force microscopy images, which can be correlated with the trapping density of the polymer electrets. The branched PDL segments not only improve stretchability but also tailor crystallinity and phase separation of the BCPs, thus increasing their charge-trapping ability. The OFET memory device with PF-b-PDL3 as the electret layer exhibited the largest memory window (102 V) and could retain its performance at up to 100% strain. This research highlights the importance of the BCP design for developing stretchable charge-trapping materials.
  • Yu-Che Chen, Yan-Cheng Lin, Hui-Ching Hsieh, Li-Che Hsu, Wei-Chen Yang, Takuya Isono, Toshifumi Satoh, Wen-Chang Chen
    JOURNAL OF MATERIALS CHEMISTRY C 9 4 1259 - 1268 2021年01月 
    We report the synthesis, morphology and photo-memory device applications of a block copolymer (BCP) consisting of poly(9,9-dioctylfluorene) (PFO) and polystyrene (PS). Three BCPs were designed with various PS contents to manipulate the structure-performance relationship of the polymer electrets in a photonic field-effect transistor-type (FET) memory device. The memory device using the BCP electret exhibited a dynamic switching behaviour with photo-writing and electrical-erasing processes. We found that the BCPs with a high PS content provided improved device performance, which could be explained by two aspects: (1) the enhanced beta -conformation of the PFO strengthened the electron-trapping capability, (2) the well-dispersed and microphase-separated morphology stabilized the trapped electrons on the interface of PFO and PS domains. Consequently, PFO5k-b-PS22k outperformed in terms of the photo-responding current along with having a high current on/off ratio of 10(4) and exhibited a retention time of more than 10000 s. Our experimental results revealed the effectiveness of using the design based on a BCP for application in photonic FET memory devices.
  • Yubo Wang, Jose Enrico Q. Quinsaat, Tomoko Ono, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Yutaka Miura, Takuya Yamamoto
    Nature Communications 11 1 2020年12月 
    AbstractNano-sized metal particles are attracting much interest in industrial and biomedical applications due to the recent progress and development of nanotechnology, and the surface-modifications by appropriate polymers are key techniques to stably express their characteristics. Herein, we applied cyclic poly(ethylene glycol) (c-PEG), having no chemical inhomogeneity, to provide a polymer topology-dependent stabilization for the surface-modification of gold nanoparticles (AuNPs) through physisorption. By simply mixing c-PEG, but not linear counterparts, enables AuNPs to maintain dispersibility through freezing, lyophilization, or heating. Surprisingly, c-PEG endowed AuNPs with even better dispersion stability than thiolated PEG (HS–PEG–OMe). The stronger affinity of c-PEG was confirmed by DLS, ζ-potential, and FT-IR. Furthermore, the c-PEG system exhibited prolonged blood circulation and enhanced tumor accumulation in mice. Our data suggests that c-PEG induces physisorption on AuNPs, supplying sufficient stability toward bio-medical applications, and would be an alternative approach to the gold–sulfur chemisorption.
  • Takuya Isono, Ryoya Komaki, Chaehun Lee, Nao Kawakami, Brian J. Ree, Kodai Watanabe, Kohei Yoshida, Hiroaki Mamiya, Takuya Yamamoto, Redouane Borsali, Kenji Tajima, Toshifumi Satoh
    Communications Chemistry 3 1 2020年12月 
    Abstract Discrete block co-oligomers (BCOs) are gaining considerable attention due to their potential to form highly ordered ultrasmall nanostructures suitable for lithographic templates. However, laborious synthetic routes present a major hurdle to the practical application. Herein, we report a readily available discrete BCO system that is capable of forming various self-assembled nanostructures with ultrasmall periodicity. Click coupling of propargyl-functionalized sugars (containing 1–7 glucose units) and azido-functionalized terpenoids (containing 3, 4, and 9 isoprene units) afforded the discrete and monodisperse BCOs with a desired total degree of polymerization and block ratio. These BCOs microphase separated into lamellar, gyroid, and cylindrical morphologies with the domain spacing (d) of 4.2–7.5 nm. Considering easy synthesis and rich phase behavior, presented BCO systems could be highly promising for application to diverse ~4-nm nanofabrications.
  • Yoshinobu Mato, Kohei Honda, Brian J. Ree, Kenji Tajima, Takuya Yamamoto, Tetsuo Deguchi, Takuya Isono, Toshifumi Satoh
    Communications Chemistry 3 1 2020年12月01日 [査読有り][通常論文]
     
    © 2020, The Author(s). The development of precise folding techniques for synthetic polymer chains that replicate the unique structures and functions of biopolymers has long been a key challenge. In particular, spiro-type (i.e., 8-, trefoil-, and quatrefoil-shaped) polymer topologies remain challenging due to their inherent structural complexity. Herein, we establish a folding strategy to produce spiro-type multicyclic polymers via intramolecular ring-opening metathesis oligomerization of the norbornenyl groups attached at predetermined positions along a synthetic polymer precursor. This strategy provides easy access to the desired spiro-type topological polymers with a controllable number of ring units and molecular weight while retaining narrow dispersity (Ɖ < 1.1). This effective strategy marks an advancement in the development of functionalized materials composed of specific three-dimensional nanostructures.
  • Saburo Kobayashi, Kaiyu Fujiwara, Dai Hua Jiang, Takuya Yamamoto, Kenji Tajima, Yasunori Yamamoto, Takuya Isono, Toshifumi Satoh
    Polymer Chemistry 11 42 6832 - 6839 2020年11月14日 
    © The Royal Society of Chemistry. In this study, we demonstrated that the Suzuki-Miyaura catalyst transfer polycondensation (SCTP) of the triolborate-type fluorene monomer, viz. potassium 2-(7-bromo-9,9-dihexyl-9H-fluorene-2-yl)triolborate, can be an efficient and versatile approach to the precise synthesis of poly[2,7-(9,9-dihexylfluorene)]s (PFs) and PF-containing block and graft copolymers. SCTP of the triolborate-type monomer proceeded rapidly in a THF/H2O mixed solvent at -10 °C using an iodobenzene derivative/Pd2(dba)3·CHCl3/t-Bu3P initiating system. Kinetic and post-polymerization experiments revealed that SCTP proceeded via the chain-growth and living polymerization mechanisms. The most important feature of the present polymerization system is that only a small amount of base and water can sufficiently promote the reaction. The well-controlled nature of this polymerization system enabled the synthesis of high-molecular-weight PFs (Mn = 5-69 kg mol-1) with narrow dispersity (ĐM = 1.14-1.38) and α-end-functionalized PFs. Most importantly, PF-containing block and graft copolymers were successfully synthesized, beginning with various iodobenzene-functionalized macroinitiators; this was difficult to achieve by the conventional SCTP of pinacolboronate-type fluorene monomer. One of the key factors for the successful block and graft copolymer syntheses is the reduced water content in the polymerization medium, which suppressed the potential precipitation/aggregation of the macroinitiators.
  • Livy Laysandra, Ching-Heng Chuang, Saburo Kobayashi, Ai-Nhan Au-Duong, Yu-Hsuan Cheng, Yen-Ting Li, Maina Moses Mburu, Takuya Isono, Toshifumi Satoh, Yu-Cheng Chiu
    ACS Applied Polymer Materials 2020年11月06日
  • Kazuaki Katagiri, Tsuyoshi Totani, Takuya Isono, Ryohei Goto, Shimpei Yamaguchi, Sonomi Kawakita, Tomoatsu Ozaki, Hirosuke Sonomura, Sayaka Minami, Shinya Honda, Katsuhiko Sasaki
    Journal of Energy Storage 31 101636 - 101636 2020年10月 [査読有り][通常論文]
  • Li-Che Hsu, Saburo Kobayashi, Takuya Isono, Yun-Chi Chiang, Brian J. Ree, Toshifumi Satoh, Wen-Chang Chen
    MACROMOLECULES 53 17 7496 - 7510 2020年09月 
    In this study, poly(3-hexylthiophene)-block-poly(delta-decanolactone)s (P3HT-b-PDLs) with the molecular architecture of AB, BAB, B(2)AB(2), and B(3)AB(3) (A: P3HT, B: PDL) were synthesized for stretchable organic field-effect transistors (OFETs) through the Cu-catalyzed azido-alkyne click reaction (CuAAC) with a high yield. The effects of triblock and branched architectures on the thermal, mechanical, and electrical properties of the prepared block copolymers were studied. Block copolymer thin films prepared from the selective solvent of cyclohexane exhibited a distinct phase separating the domain of P3HT with a nanofibrillar structure. Grazing-incidence X-ray scattering results indicated that all of the block copolymer thin films possessed the P3HT crystalline domains with the same domain spacing regardless of the branched architecture. However, the branched soft segments led to a more random phase separation of the block copolymer and lower crystallinity of the P3HT block. Consequently, thin films made by the triblock copolymers with branched PDL segments (B(2)AB(2) and B(3)AB(3)) exhibited favorable electrical properties with significantly improved stretchability and smaller elastic modulus. The carrier mobility of the block copolymer-based OFETs showed a comparable performance to that of the pristine P3HT homopolymer. Also, the B(3)AB(3)-based OFET could maintain 72-75% on the charge mobility under 100% strain and 71-75% after 500 stretch-release cycles at 50% strain. The study revealed that the stretchability of the conjugated/elastic block copolymers can be significantly enhanced by our architecture design without losing their semiconducting property.
  • Chiaki Hori, Tomohiro Sugiyama, Kodai Watanabe, Jian Sun, Yuu Kamada, Toshihiko Ooi, Takuya Isono, Toshifumi Satoh, Shin-ichiro Sato, Seiichi Taguchi, Ken'ichiro Matsumoto
    Polymer Degradation and Stability 179 109231 - 109231 2020年09月 [査読有り][通常論文]
  • Brian J. Ree, Yusuke Satoh, Takuya Isono, Toshifumi Satoh
    Nano Letters 2020年07月28日 [査読有り][通常論文]
  • Yun‐Chi Chiang, Chih‐Chien Hung, Yan‐Cheng Lin, Yu‐Cheng Chiu, Takuya Isono, Toshifumi Satoh, Wen‐Chang Chen
    Advanced Materials 2002638 - 2002638 2020年07月23日 [査読有り][通常論文]
  • Muhammad Mumtaz, Yasuko Takagi, Hiroaki Mamiya, Kenji Tajima, Cécile Bouilhac, Takuya Isono, Toshifumi Satoh, Redouane Borsali
    European Polymer Journal 134 109831 - 109831 2020年07月 [査読有り][通常論文]
  • Takuya Isono, Saki Nakahira, Hui-Ching Hsieh, Satoshi Katsuhara, Hiroaki Mamiya, Takuya Yamamoto, Wen-Chang Chen, Redouane Borsali, Kenji Tajima, Toshifumi Satoh
    Macromolecules 2020年06月16日 [査読有り][通常論文]
  • Brian J. Ree, Takuya Isono, Toshifumi Satoh
    ACS Applied Materials & Interfaces 12 25 28435 - 28445 2020年06月11日 [査読有り][通常論文]
     
    Recent advancements in modern microelectronics continuously increase the data storage capacity of modern devices, but they require delicate and costly fabrication processes. As alternatives to conventional inorganic based semiconductors, semiconducting polymers are of academic and industrial interest for their cost-efficiency, power efficiency, and flexible processability. Here, we have synthesized a series of novel oxygen-based polymers through the postmodification reactions of poly(ethylene-alt-maleate) with various oxybenzyl alcohol derivatives. The oxygen-based polymers are thermally stable up to 180 degrees C, and their nanoscale film devices exhibit reliable, power efficient p-type unipolar volatile and nonvolatile resistive memory characteristics with high ON/OFF current ratios. Additionally, when given a higher number of oxygen atoms in oxyphenyl side groups, the thin film polymer devices demonstrate a wide operational film thickness range. The memory characteristics depend on the oxyphenyl moieties functioning as charge trap sites, where a combination of Schottky emission and trap-limited space charge limited conductions in OFF-state and hopping conduction in ON-state are observed. This study demonstrates the chemical incorporation of oxyphenyl derivatives into polymer dielectrics as a powerful development tool for p-type resistive memory materials.
  • Tsung-Han Chuang, Yun-Chi Chiang, Hui-Ching Hsieh, Takuya Isono, Chao-Wei Huang, Redouane Borsali, Toshifumi Satoh, Wen-Chang Chen
    ACS Applied Materials & Interfaces 12 20 23217 - 23224 2020年05月20日 [査読有り][通常論文]
  • Tajima, Kenji, Tahara, Koutaro, Ohba, Junya, Kusumoto, Ryo, Kose, Ryota, Kono, Hiroyuki, Matsushima, Tokuo, Fushimi, Koji, Isono, Takuya, Yamamoto, Takuya, Satoh, Toshifumi
    BIOMACROMOLECULES 21 2 581 - 588 2020年02月 [査読有り][通常論文]
     
    Nanofibrillated bacterial cellulose (NFBC) is produced by culturing a cellulose-producing bacterium under agitated aerobic conditions in a carboxymethylcellulose (CMC)-supplemented medium. Detailed structural analyses revealed that NFBC fiber widths varied with the degree of substitution of the CMC used, and zeta potential values decreased with the increment of CMC concentration in the medium. Transmission electron microscopy observation after immunostaining demonstrated that CMC molecules were present on the NFBC microfibril surfaces. We tested NFBC for utility as a binder for a display device that uses electrochromic (EC) material. Introduction of a quaternary ammonium group into the EC molecules enhanced their interactions with the negatively charged NFBC microfibrils. A casting process homogeneously adsorbed the EC molecules onto the surface of a transparent electrode with NFBC. A homogeneous color change was successfully observed upon applying an electric field, suggesting that NFBC could be used as a binder material for uniform surface adsorption.
  • Hiroyuki Kono, Nobuhiro Kondo, Takuya Isono, Makoto Ogata, Katsuki Hirabayashi
    Data in Brief 28 104993 (5 pages)  2020年02月 [査読有り][通常論文]
     
    We report the solid-state nuclear magnetic resonance (NMR) relaxation dataset for a triple helix and a random structure of water-soluble Aureobasidium pullulans β-(1→3, 1→6)-ᴅ-glucan (APG) and those of schizophyllan from Schizophyllum commune (SPG), obtained by the Bruker BioSpin 500 MHz NMR spectrometer. These data include solid-state proton spin-lattice relaxation in the rotating frame (T1ρH) and 13C spin-lattice relaxation (T1C) of these two β-(1→3, 1→6)-glucans, which are related to the subject of article in International Journal of Biological Macromolecules, entitled “Characterization of the secondary structure and order–disorder transition of a β-(1→3, 1→6)-glucan from Aureobasidium pullulans” [1]. Data can help to investigate the structural characterization of the structural polysaccharides.
  • Kaoru Takojima, Hiroshi Makino, Tatsuya Saito, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Polymer Chemistry 2020年 

    The alternating copolymer of lactic acid and glycolic acid (PLGA) is a highly promising next generation biodegradable material for biomedical and pharmaceutical applications due to its uniform degradation behaviors in...

  • Kodai Watanabe, Satoshi Katsuhara, Hiroaki Mamiya, Yukihiko Kawamura, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Nanoscale 2020年 [査読有り][通常論文]
     

    Highly asymmetric lamellar (A-LAM) nanostructure is one of the most important template geometries for block copolymer (BCP) lithography. However, A-LAM is unattainable from conventional BCPs, and there is no general...

  • Satoshi Katsuhara, Hiroaki Mamiya, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Polymer Chemistry 2020年 [査読有り][通常論文]
  • Jiang, D.-H., Kobayashi, S., Jao, C.-C., Mato, Y., Isono, T., Fang, Y.-H., Lin, C.-C., Satoh, T., Tung, S.-H., Kuo, C.-C.
    Polymers 12 1 84 - 84 2020年 [査読有り][通常論文]
  • Kaoru Takojima, Tatsuya Saito, Cedric Vevert, Viko Ladelta, Panayiotis Bilalis, Jun Watanabe, Shintaro Hatanaka, Takashi Konno, Takuya Yamamoto, Kenji Tajima, Nikos Hadjichristidis, Takuya Isono, Toshifumi Satoh
    Polymer Journal 52 1 103 - 110 2020年01月 [査読有り][通常論文]
  • Hiroyuki Kono, Nobuhiro Kondo, Takuya Isono, Makoto Ogata, Katsuki Hirabayashi
    International Journal of Biological Macromolecules in press 2020年 [査読有り][通常論文]
     
    This study revealed the secondary structures of the water-soluble Aureobasidium pullulans β-(1→3, 1→6)-D-glucan (APG) whose primary structural unit is a β-(1→3)-D-glucan backbone with four β-(1→6)-D-glucosyl branching units every six residues. Solid-state NMR spectroscopy, X-ray diffractometry (XRD), and small-angle X-ray scattering (SAXS) experiments involving samples prepared from lyophilized APG dissolved in H2O or DMSO showed that APG forms a triple helix in H2O and a random structure in DMSO. In addition, it was revealed that the transformation from the triple helix of APG to the random structure occurs reversibly, and that the triple helix is recovered from the random structure in DMSO/H2O mixtures containing more than 30% H2O. Solid-state NMR and diffraction studies revealed that the triple helix of APG is more stable than that of SPG. The APG helical pitch is 1.82 nm, which is about 10% longer than that of the triple helix of schizophyllan whose structure comprises a β-(1→3)-D-glucan backbone with one β-(1→6)-D-branching unit every three residues. These findings show that the β-(1→6) side-chain frequency strongly affects the stability and helical pitch of a β-(1→3, 1→6)-D-glucan.
  • Kazuaki Katagiri, Ryohei Gotoh, Tsuyoshi Totani, Takuya Isono, Shimpei Yamaguchi, Takuya Ehiro, Hirosuke Sonomura, Tomoatsu Ozaki, Sonomi Kawakita, Yayoi Yoshioka, Sayaka Minami, Shinya Honda, Katsuhiko Sasaki
    Journal of Energy Storage 26 100980-1 - 100980-6 2019年12月 [査読有り][通常論文]
     
    © 2019 Elsevier Ltd This work presents a method to fabricate the heat-storable CFRP, a multifunctional composite that combines strength, lightweight and heat storability. For mobile electric devices, thermal management system using phase change material (PCM) has been developed. However, as long as the PCM changes to liquid phase, it is difficult to reduce the weight since the sealed container is indispensable. Hence, the authors have focused trans-1,4-polybutadiene (TPBD), which is crystalline polymer that accumulates heat by crystal structure transition in solid phase. In this study, TPBD was incorporated into CFRP. To avoid exposing TPBD to high-temperature and high-pressure processes, the electrodeposition resin molding (ERM) method was applied. That is, a non-crimp carbon fiber fabric (NCF) was immersed in the electrodeposition solution containing epoxy polymers in which the pulverized TPBD was dispersed. Applying a current, resin was deposited and impregnated between carbon fibers. Simultaneously, TPBD was incorporated to obtain heat-storable CFRP.
  • Wu PH, Lin YC, Laysandra L, Lee MH, Chiu YC, Isono T, Satoh T, Chen WC
    Macromolecular rapid communications e1900542  2019年12月 [査読有り][通常論文]
  • Chiang Yun-Chi, Kobayashi Saburo, Isono Takuya, Shih Chien-Chung, Shingu Tomoki, Hung Chih-Chien, Hsieh Hui-Ching, Tung Shih-Huang, Satoh Toshifumi, Chen Wen-Chang
    POLYMER CHEMISTRY 10 40 5452 - 5464 2019年10月28日 [査読有り][通常論文]
  • Yoshida Kohei, Yamamoto Takuya, Tajima Kenji, Isono Takuya, Satoh Toshifumi
    POLYMER CHEMISTRY 10 24 3390 - 3398 2019年06月28日 [査読有り][通常論文]
  • Tatsuya Saito, Kaoru Takojima, Takafumi Oyama, Shintaro Hatanaka, Takashi Konno, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    ACS Sustainable Chemistry & Engineering 7 9 8868 - 8875 2019年05月06日 [査読有り][通常論文]
  • Takafumi Oyama, Shingo Kobayashi, Tetsuo Okura, Shunsuke Sato, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    ACS Sustainable Chemistry & Engineering 7 8 7969 - 7978 2019年04月15日 [査読有り][通常論文]
  • Kodai Watanabe, Satoshi Katsuhara, Hiroaki Mamiya, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Chemical science 10 11 3330 - 3339 2019年03月21日 [査読有り][通常論文]
     
    A novel strategy for downsizing the feature of microphase-separated structures was developed via the intramolecular crosslinking reaction of block copolymers (BCPs) without changing the molecular weight. A series of BCPs consisting of poly[styrene-st-(p-3-butenyl styrene)] and poly(rac-lactide) (SBS-LA) was subjected to Ru-catalyzed olefin metathesis under highly diluted conditions to produce intramolecularly crosslinked BCPs (SBS(cl)-LAs). Small-angle X-ray scattering measurement and transmission electron microscopy observation of the SBS(cl)-LAs revealed feature size reduction in lamellar (LAM) and hexagonally close-packed cylinder (HEX) structures in the bulk state, which was surely due to the restricted chain dimensions of the intramolecularly crosslinked SBS block. Notably, the degree of size reduction was controllable by varying the crosslink density, with a maximum decrease of 22% in the LAM spacing. In addition, we successfully observed the downsizing of the HEX structure in the thin film state using atomic force microscopy, indicating the applicability of the present methodology to next-generation lithography technology.
  • Isono Takuya, Kawakami Nao, Watanabe Kodai, Yoshida Kohei, Otsuka Issei, Mamiya Hiroaki, Ito Hajime, Yamamoto Takuya, Tajima Kenji, Borsali Redouane, Satoh Toshifumi
    POLYMER CHEMISTRY 10 9 1119 - 1129 2019年03月07日 [査読有り][通常論文]
  • Post-polymerization modification of PS-b-PMMA for achieving directed self-assembly with sub-10nm feature size
    Takuya Isono, Kohei Yoshida, Hiroaki Mamiya, Ken Miyagi, Akiyoshi Yamzaki, Toshifumi Satoh
    Proceedings of SPIE 10960 109600U-1 - 109600U-8 2019年03月 [査読無し][通常論文]
  • Yoshinobu Mato, Kohei Honda, Kenji Tajima, Takuya Yamamoto, Takuya Isono, Toshifumi Satoh
    Chemical science 10 2 440 - 446 2019年01月14日 [査読有り][通常論文]
     
    Cage-shaped polymers, or "macromolecular cages", are of great interest as the macromolecular analogues of molecular cages because of their various potential applications in supramolecular chemistry and materials science. However, the systematic synthesis of macromolecular cages remains a great challenge. Herein, we describe a robust and versatile synthetic strategy for macromolecular cages with defined arm numbers and sizes based on the intramolecular consecutive cyclization of highly reactive norbornene groups attached to each end of the arms of a star-shaped polymer precursor. The cyclizations of three-, four-, six-, and eight-armed star-shaped poly(ε-caprolactone)s (PCLs) bearing a norbornenyl group at each arm terminus were effected with Grubbs' third generation catalyst at high dilution. 1H NMR, SEC, and MALDI-TOF MS analyses revealed that the reaction proceeded to produce the desired macromolecular cages with sufficient purity. The molecular sizes of the macromolecular cages were controlled by simply changing the molecular weight of the star-shaped polymer precursors. Systematic investigation of the structure-property relationships confirmed that the macromolecular cages adopt a much more compact conformation, in both the solution and bulk states, as compared to their linear and star-shaped counterparts. This synthetic approach marks a significant advance in the synthesis of complex macromolecular architectures and provides a platform for novel applications using cage-shaped molecules with polymer frameworks.
  • Tatsuya Fukushima, Hirotaka Ishibashi, Daichi Suemasa, Ryosuke Nakamura, Masanobu Yomogida, Takuya Isono, Toshifumi Satoh, Hironori Kaji
    JOURNAL OF POLYMER SCIENCE, PART B: POLYMER PHYSICS 2019年01月 [査読有り][通常論文]
  • Ree Brian J, Lee Jongchan, Satoh Yusuke, Kwon Kyungho, Isono Takuya, Satoh Toshifumi, Ree Moonhor
    POLYMERS 10 12 2018年12月 [査読有り][通常論文]
     
    Micelles were prepared in organic solvents by using three topological polymer amphiphiles: (i) cyclic poly(n-decyl glycidyl ether-block-2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether) (c-PDGE-b-PTEGGE) and (ii) its linear analogue (l-PDGE-b-PTEGGE); (iii) linear poly(6-phosphorylcholinehexylthiopropyl glycidyl ether-block-n-dodecanoyl glycidyl ether) (l-PPCGE-b-PDDGE). For the individual micelle solutions, the size and distribution were determined by dynamic light scattering (DLS) and synchrotron X-ray scattering analyses. The synchrotron X-ray scattering analysis further found that c-PDGE-b-PTEGGE forms oblate ellipsoidal micelle in an ethanol/water mixture, l-PDGE-b-PTEGGE makes prolate ellipsoidal micelle in an ethanol/water mixture, and l-PPCGE-b-PDDGE forms cylindrical micelle in chloroform. This comparative study found that there are large differences in the size and distribution results extracted by DLS and X-ray scattering analyses. All possible factors to cause such large differences are discussed. Moreover, a better use of the DLS instrument with keeping its merits is proposed.
  • Yamamoto Takuya, Hosokawa Masaaki, Nakamura Minato, Sato Shin-ichiro, Isono Takuya, Tajima Kenji, Satoh Toshifumi, Sato Masamichi, Tezuka Yasuyuki, Saeki Akinori, Kikkawa Yoshihiro
    MACROMOLECULES 51 22 9284 - 9293 2018年11月27日 [査読有り][通常論文]
  • Yoshida Kohei, Tanaka Shunma, Yamamoto Takuya, Tajima Kenji, Borsali Redouane, Isono Takuya, Satoh Toshifumi
    MACROMOLECULES 51 21 8870 - 8877 2018年11月13日 [査読有り][通常論文]
  • Yoshida Kohei, Tian Lin, Miyagi Ken, Yamazaki Akiyoshi, Mamiya Hiroaki, Yamamoto Takuya, Tajima Kenji, Isono Takuya, Satoh Toshifumi
    MACROMOLECULES 51 20 8064 - 8072 2018年10月23日 [査読有り][通常論文]
  • Tomoki Shingu, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Polymers 10 8 2018年08月06日 [査読有り][通常論文]
     
    Cyclic polymers exhibit unique physical and chemical properties because of the restricted chain mobility and absence of chain ends. Although many types of homopolymers and diblock copolymers possessing cyclic architectures have been synthesized to date, there are relatively few reports of cyclic triblock terpolymers because of their synthetic difficulties. In this study, a novel synthetic approach for μ-ABC tricyclic miktoarm star polymers involving t-Bu-P₄-catalyzed ring-opening polymerization (ROP) of glycidyl ethers and intramolecular copper-catalyzed azido-alkyne cycloaddition (CuAAC) was developed. First, the t-Bu-P₄-catalyzed ROP of decyl glycidyl ether, dec-9-enyl glycidyl ether, and 2-(2-(2-methoxyethoxy) ethoxy) ethyl glycidyl ether with the aid of functional initiators and terminators was employed for the preparation of a clickable linear triblock terpolymer precursor possessing three azido and three ethynyl groups at the selected positions. Next, the intramolecular CuAAC of the linear precursor successfully produced the well-defined tricyclic triblock terpolymer with narrow dispersity in a reasonable yield. The present strategy is useful for synthesizing model polymers for studying the topological effects on the triblock terpolymer self-assembly.
  • Hsieh Hui-Ching, Hung Chih-Chien, Watanabe Kodai, Chen Jung-Yao, Chiu Yu-Cheng, Isono Takuya, Chiang Yun-Chi, Reghu Renji R, Satoh Toshifumi, Chen Wen-Chang
    POLYMER CHEMISTRY 9 27 3820 - 3831 2018年07月21日 [査読有り][通常論文]
  • Hung Chih-Chien, Nakahira Saki, Chiu Yu-Cheng, Isono Takuya, Wu Hun-Chin, Watanabe Kodai, Chiang Yun-Chi, Takashima Shoichi, Borsali Redouane, Tung Shih-Huang, Satoh Toshifumi, Chen Wen-Chang
    MACROMOLECULES 51 13 4966 - 4975 2018年07月10日 [査読有り][通常論文]
  • 磯野拓也, 佐藤敏文
    CSJ Current Review 29 58‐68,1(1)  2018年05月28日 [査読無し][通常論文]
  • Takuya Isono, Tetsuya Sasamori, Kohei Honda, Yoshinobu Mato, Takuya Yamamoto, Kenji Tajima, Toshifumi Satoh
    Macromolecules 51 10 3855 - 3864 2018年05月22日 [査読有り][通常論文]
     
    A novel synthesis of multicyclic polymers that feature ultradense arrays of cyclic polymer units has been developed by exploiting the cyclopolymerization of α,ω-norbornenyl end-functionalized macromonomers mediated by the Grubbs third-generation catalyst (G3). Owing to the living polymerization nature, the number of cyclic repeating units in these multicyclic polymers was controlled to be between 1 and approximately 70 by varying the initial macromonomer-to-G3 ratio. The ring size was also tuned by choosing the molecular weight of the macromonomer in this way we successfully prepared multicyclic polymers that possess cyclic repeating units composed of up to about 500 atoms, which by far exceeds those prepared to date by cyclopolymerization. Specifically, cyclopolymerizations of α,ω-norbornenyl end-functionalized poly(l-lactide)s (PLLAs) proceeded homogeneously under highly dilute conditions (∼0.1 mM in CH2Cl2) to give multicyclic polymers that feature cyclic PLLA repeating units on the polynorbornene backbone. The cyclic product architectures were confirmed not only by structural characterization based on NMR, MALDI-TOF MS, and SEC analyses but also by comparing their glass transition temperatures, viscosities, and hydrodynamic radii with their acyclic counterparts. The cyclopolymerization strategy was applicable to a variety of α,ω-norbornenyl end-functionalized macromonomers, such as poly(ϵ-caprolactone), poly(ethylene glycol) (PEG), poly(tetrahydrofuran), and PLLA-b-PEG-b-PLLA. The successful statistical and block cyclocopolymerizations of the PLLA and PEG macromonomers gave amphiphilic multicyclic copolymers.
  • Takuya Isono, Hoyeol Lee, Kana Miyachi, Yusuke Satoh, Toyoji Kakuchi, Moonhor Ree, Toshifumi Satoh
    Macromolecules 51 8 2939 - 2950 2018年04月24日 [査読無し][通常論文]
     
    A series of brush block copolymers (BBCPs) consisting of poly(decyl glycidyl ether) (PDGE) and poly(10-hydroxyldecyl glycidyl ether) (PHDGE) blocks, having four different types of chain tacticities, i.e., [at-PDGE]-b-[at-PDEGE], [at-PDGE]-b-[it-PDEGE], [it-PDGE]-b-[at-PDEGE], and [it-PDGE]-b-[it-PDEGE], where the it and at represent the isotactic and atactic chains, respectively, were prepared by t-Bu-P4-catalyzed sequential anionic ring-opening polymerization of glycidyl ethers followed by side-chain modification. The corresponding homopolymers, i.e., at-PDGE, it-PDGE, at-PHDGE, and it-PHDGE, were also prepared for comparison with the BBCPs. The PDGE homopolymers were significantly promoted in the phase transitions and morphological structure formation by the isotacticity formation. In particular, it-PDGE was found to form only a horizontal multibilayer structure with a monoclinic lattice in thin films, which was driven by the bristles' self-assembling ability and enhanced by the isotacticity. However, the PHDGE homopolymers were found to reveal somewhat different behaviors in the phase transitions and morphological structure formation by the tacticity control due to the additional presence of a hydroxyl group in the bristle end as an H-bonding interaction site. The H-bonding interaction could be enhanced by the isotacticity formation. The it-PHDGE homopolymer formed only the horizontal multibilayer structure, which was different from the formation of a mixture of horizontal and tilted multibilayer structures in at-PHDGE. The structural characteristics were further significantly influenced by the diblock formation and the tacticity of the counterpart block. Because of the strong self-assembling characteristics of the individual block components, all the BBCPs formed separate crystals rather than cocrystals. The isotacticity always promoted the formation of better quality morphological structures in terms of their lateral ordering and orientation.
  • Boram Kim, Chang-Geun Chae, Yusuke Satoh, Takuya Isono, Min-Kyoon Ahn, Cheong-Min Min, Jin-Hyeok Hong, Carolina Frias Ramirez, Toshifumi Satoh, Jae-Suk Lee
    Macromolecules 51 6 2293 - 2301 2018年03月27日 [査読無し][通常論文]
     
    Hard-soft-hard triblock copolymers based on poly(ethylene oxide) (PEO), poly(2-naphthyl glycidyl ether)-block-poly[2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether]-block-poly(2-naphthyl glycidyl ether)s (PNG-PTG-PNGs), were synthesized by sequential ring-opening polymerization of 2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether and 2-naphthyl glycidyl ether using a bidirectional initiator catalyzed by a phosphazene base. Four PNG-PTG-PNGs had different block compositions (fwt,PNG = 9.2-28.6 wt %), controlled molecular weights (Mn = 23.9-30.9 kDa), and narrow dispersities (Crossed D sign = 1.11-1.14). Most of the PNG-PTG-PNG electrolytes had much higher Li+ conductivities than that of a PEO electrolyte (6.54 × 10-7 S cm-1) at room temperature. Eespecially, the Li+ conductivity of PNG18-PTG107-PNG18 electrolyte (9.5 × 10-5 S cm-1 for fwt,PNG = 28.6 wt %) was comparable to one of a PTG electrolyte (1.11 × 10-4 S cm-1). The Li+ conductivities of PNG-PTG-PNG electrolytes were closely correlated to efficient Li+ transport channels formed by the microphase separation into soft PTG and hard PNG domains.
  • Tatsuya Saito, Yusuke Aizawa, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    Macromolecules 51 3 689 - 696 2018年02月13日 [査読有り][通常論文]
     
    Alkali metal carboxylates were discovered as efficient and simple catalysts for the ring-opening polymerization of cyclic esters that are alternatives to conventional metal-based catalysts and organocatalysts. In our system using an alcohol initiator and this simple catalyst, biodegradable and biocompatible aliphatic polyesters, such as poly(lactide), poly(e-caprolactone), poly(δ-valerolactone), and poly(trimethylene carbonate), were obtained with predictive molecular weights ranging from 3500 to 22-600 and narrow dispersities. A kinetic experiment for the ROP of l-lactide confirmed the controlled/living nature of the present ROP system, which allowed the precise synthesis of end-functionalized polyesters as well as multihydroxyl-containing polyesters, including α,hydroxy telechelic and star-shaped polyesters. Furthermore, a block copolymer containing the poly(l-lactide) segment was successfully synthesized using a macroinitiator possessing a hydroxyl group at the chain end. The tunability of the alkali metal carboxylates by the appropriate choice of the alkyl moiety and countercation enables not only control of the polymerization behavior but also expansion of the scope of the applicable monomers. Given the low cost, easy handling, and low toxicity of the alkali metal carboxylates, the present ROP system can be highly promising for both laboratory- and industrial-scale polyester productions.
  • Ken'Ichiro Matsumoto, Chiaki Hori, Ryunosuke Fujii, Masahiro Takaya, Takashi Ooba, Toshihiko Ooi, Takuya Isono, Toshifumi Satoh, Seiichi Taguchi
    Biomacromolecules 19 2 662 - 671 2018年02月12日 [査読有り][通常論文]
     
    Biological polymer synthetic systems, which utilize no template molecules, normally synthesize random copolymers. We report an exception, a synthesis of block polyhydroxyalkanoates (PHAs) in an engineered Escherichia coli. Using an engineered PHA synthase, block copolymers poly[(R)-2-hydroxybutyrate(2HB)-b-(R)-3-hydroxybutyrate(3HB)] were produced in E. coli. The covalent linkage between P(2HB) and P(3HB) segments was verified with solvent fractionation and microphase separation. Notably, the block sequence was generated under the simultaneous consumption of two monomer precursors, indicating the existence of a rapid monomer switching mechanism during polymerization. Based on in vivo metabolic intermediate analysis and the relevant in vitro enzymatic activities, we propose a model in which the rapid intracellular 3HB-CoA fluctuation during polymer synthesis is a major factor in generating block sequences. The dynamic change of intracellular monomer levels is a novel regulatory principle of monomer sequences of biopolymers.
  • Takuya Isono, Brian J. Ree, Kenji Tajima, Redouane Borsali, Toshifumi Satoh
    Macromolecules 51 2 428 - 437 2018年01月23日 [査読有り][通常論文]
     
    Microphase-separated structures of block copolymers (BCPs) have attracted considerable attention for their potential application in the bottom-up fabrication of 10 nm scale nanostructured materials. To realize sustainable development within this field, the creation of novel BCP materials from renewable biomass resources is of fundamental interest. Thus, we herein focused on maltoheptaose-b-poly(δ-decanolactone)-b-maltoheptaose (MH-b-PDL-b-MH) as a sustainable alternative for nanostructure-forming BCPs, in which both constitutional blocks can be derived from renewable biomass resources, in the case, δ-decanolactone and amylose. Well-defined MH-b-PDL-b-MHs with varying PDL lengths were synthesized through a combination of controlled/living ring-opening polymerization and the click reaction. The prepared MH-b-PDL-b-MHs successfully self-assembled into highly ordered hexagonal cylindrical structures with a domain-spacing of ∼12-14 nm in both the bulk and thin film states. Interestingly, the as-cast thin films of MH-b-PDL-b-MHs (with PDL lengths of 9K and 13K) form horizontal cylinders, with thermal annealing (180 °C, 30 min) resulting in a drastic change in the domain orientation from horizontal to vertical. Thus, the results presented herein demonstrated that the combination of oligosaccharides and biomass-derived hydrophobic polymers appears promising for the sustainable development of nanotechnology and related fields.
  • Brian J. Ree, Yusuke Satoh, Kyeong Sik Jin, Takuya Isono, Won Jong Kim, Toyoji Kakuchi, Toshifumi Satoh, Moonhor Ree
    NPG ASIA MATERIALS 9 2017年12月 [査読有り][通常論文]
     
    This study reports the first well-defined and stable nanomicelles (20 - 30 nm in diameter) self-assembled from amphiphilic brush (comb-like) cyclic and tadpole-shaped copolymers composed of hydrophobic n-decyl and hydrophilic 2-(2-methoxyethoxy)ethoxy) ethyl bristle blocks based on a poly(glycidyl ether) backbone. The micelle formation behaviour and structural details were investigated by synchrotron X-ray scattering analysis in a rigorous and complementary manner. The amphiphilic brush cyclic topology facilitates more compact and stable aggregation behaviour in the micelle core and a more densely packed corona, which prevents intermicellar aggregation. The presence of a hydrophobic component with brush cyclic topology inside the core is identified as the primary micelle stabilizing factor, enabling stable core aggregation and sharper core-corona interface formation. The presence of a hydrophilic brush cyclic component in the corona is determined as the secondary micelle stabilizing factor, helping nullify the corona penetration by polymer chains from other micelles and ultimately prevent the intermicellar aggregation-mediated collapse of the micellar structure. Overall, the brush cyclic topology was confirmed to be beneficial for forming highly stable nanomicelles with an extremely narrow (pseudo-monodisperse) size distribution compared with conventional linear topology and tadpole topologies. All the results of this study provide a unique opportunity for designing advanced functional high-performance amphiphilic materials for nanomicelles that are unattainable by other conventional methods and broadening their applications in various fields, including drug delivery, biomedical imaging, foods, cosmetics, smart coatings, photonics and molecular electronics.
  • Kenji Tajima, Ryo Kusumoto, Ryota Kose, Hiroyuki Kono, Tokuo Matsushima, Takuya Isono, Takuya Yamamoto, Toshifumi Satoh
    BIOMACROMOLECULES 18 10 3432 - 3438 2017年10月 [査読有り][通常論文]
     
    Nanofibrillated bacterial cellulose (NFBC) is produced by culturing a cellulose-producing bacterium (Gluconacetobacter intermedius NEDO-01) with rotation or agitation in medium supplemented with carboxymethylcellulose (CMC). Despite a high yield and dispersibility in water, the product immediately aggregates in organic solvents. To broaden its applicability, we prepared amphiphilic NFBC by culturing strain NEDO-01 in medium supplemented with hydroxyethylcellulose or hydroxypropylcellulose instead of CMC. Transmission electron microscopy analysis revealed that the resultant materials (HE-NFBC and HP-NFBC, respectively) comprised relatively uniform fibers with 'diameters of 33 +/- 7 and 42 +/- 8 nm, respectively. HP-NFBC was dispersible in polar organic solvents such as methanol, acetone, isopropyl alcohol, acetonitrile, tetrahydrofuran (THF), and dimethylformamide, and was also dispersible in poly(methyl methacrylate) (PMMA) by solvent mixing using THF. HP-NFBC/PMMA composite films were highly transparent and had a higher tensile strength than neat PMMA film. Thus, HP-NFBC has a broad range of applications, including as a filler material.
  • Takuya Isono, Kana Miyachi, Yusuke Satoh, Shin-ichiro Sato, Toyoji Kakuchi, Toshifumi Satoh
    POLYMER CHEMISTRY 8 37 5698 - 5707 2017年10月 [査読有り][通常論文]
     
    This paper describes a comprehensive study of the lower critical solution temperature (LCST)-type thermoresponsive properties of various poly(glycidyl ether) homopolymers with a varying side chain structure, molecular weight, and main chain tacticity, as well as their copolymers with a varying monomer composition and monomer sequence. For the initial screening, we prepared nine kinds of poly(glycidyl ether)s by the phosphazene base-catalyzed ring-opening polymerization of glycidyl methyl ether (MeGE), ethyl glycidyl ether (EtGE), glycidyl isopropyl ether (iPrGE), 2-methoxyethyl glycidyl ether (MeEOGE), 2-ethoxyethyl glycidyl ether (EtEOGE), 2-propoxyethyl glycidyl ether (PrEOGE), 2-(2- methoxyethoxy) ethyl glycidyl ether (MeEO(2)GE), 2-(2-ethoxyethyl) ethyl glycidyl ether (EtEO(2)GE), and 2-(2-(2-methoxyethoxy) ethoxy) ethyl glycidyl ether (MeEO(3)GE). Among them, poly(MeGE), poly(EtGE), poly(MeEOGE), poly(EtEOGE), and poly(MeEO(2)GE) (M-n = ca. 5000 g mol(-1)) were found to exhibit a LCST-type phase transition in water at 65.5 degrees C, 10.3 degrees C, 91.6 degrees C, 41.3 degrees C, and 58.2 degrees C, respectively. Although the molecular weight and main chain tacticity had little impact on the phase transition temperature, the side chain structure, i.e., the number of oxyethylene units and terminal alkyl groups, significantly affected the transition temperature. The statistical copolymers composed of MeEOGE and EtEOGE revealed that the transition temperature of the polymer can be desirably customized in between those of the homopolymers by varying the monomer composition. On the other hand, we found that the block copolymer composed of MeEOGE and EtEOGE exhibited a complex thermoresponsive behavior due to its ability to form a micellar aggregate.
  • Camila Utsunomia, Tatsuya Saito, Ken'ichiro Matsumoto, Chiaki Hori, Takuya Isono, Toshifumi Satoh, Seiichi Taguchi
    JOURNAL OF POLYMER RESEARCH 24 10 2017年09月 [査読有り][通常論文]
     
    D-Lactate (LA)-based oligomers (D-LAOs), consisting of D-LA and D-3-hydroxybutyrate (D-3HB), are biobased compounds which are produced and spontaneously secreted by recombinant Escherichia coli. By supplementing the bacterial cultivation with diethylene glycol (DEG), the oligomers featuring hydroxyl groups at both ends of their structures, the D-LAOs-DEG, can be efficiently biosynthesized. In the present work, we attempted to verify the feasibility of D-LAOs-DEG as building blocks to be assembled into LA-based poly(ester-urethane) via polyaddition reactionwith diisocyanate. The polymeric products were demonstrated by SEC and the urethane bound formation in the polymer was determined by FT-IR analysis, indicating that the polymerization was successfully performed. These results suggested that the one-step biosynthesized D-LAOs-DEG are potential substrates for the synthesis of LA-based poly(ester-urethane) and can be further applied to the synthesis of other LA copolymers.
  • Ryoto Tanaka, Kodai Watanabe, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    POLYMER CHEMISTRY 8 23 3647 - 3656 2017年06月 [査読無し][通常論文]
     
    The effect of intramolecular cross-linking in an amphiphilic block copolymer (BCP) system was systematically investigated in terms of its thermal properties, critical micelle concentration (CMC), and aqueous self-assembly. A series of linear BCPs consisting of poly(ethylene glycol) (PEG) as a hydrophilic block and poly(epsilon-caprolactone-co-7-allyloxepan-2-one) (P(CL-co-ACL)) as a hydrophobic block were prepared by the ring-opening copolymerization of epsilon-caprolactone (CL) and 7-allyloxepan-2-one (ACL) using poly (ethylene glycol) monomethyl ether as an initiator. The intramolecular olefin metathesis reaction in the P(CL-co-ACL) block was subsequently carried out under various conditions to prepare the cross-linked BCPs with different degrees of cross-linking. The thermal analysis confirmed that the linear P(CL-co-ACL) block was found to crystallize, while the cross-linked one showed no crystallinity. In addition, glass transition temperature of the P(CL-co-ACL) block increased upon cross-linking. On the other hand, the intramolecular cross-linking had no significant influence on the CMC. The self-assembled micelles were prepared from the obtained BCPs and their size and morphology were investigated. For the BCPs with relatively short PEG chains, the micellar size decreased from 36.6 nm to 16.7 nm as the degree of cross-linking of the P(CL-co-ACL) block increased. On the other hand, the BCPs with relatively long PEG chains showed a change in the micellar morphology from spherical micelles to short worm and large compound micelles upon cross-linking.
  • Jau-Tzeng Wang, Shoichi Takshima, Hung-Chin Wu, Chien-Chung Shih, Takuya Isono, Toyoji Kakuchi, Toshifumi Satoh, Wen-Chang Chen
    MACROMOLECULES 50 4 1442 - 1452 2017年02月 [査読無し][通常論文]
     
    We report the synthesis, morphology, and properties of poly(3-hexylthiophene)-block-poly(butyl acrylate) (P3HT-b-PBA) for stretchable electronics applications, which are consisted of semiconducting P3HT and low glass transistion temperature (T-g) PBA blocks. The P3HT-b-PBA thin films self-assembled into fibrillar-like nanostructures and maintained the edge-on oreientation even at a low P3HT composition, based on the results from atomic force microscopy (AFM) and grazing incidence X-ray diffraction (GIRD). By varying the P3HT/PBA ratio, the tensile modulus decreased as the block length of PBA increased, from 0.93 GPa for P3HT to 0.19 GPa for P3HT-b-PBA(12k). The field effect transistor (FET) using P3HT-b-PBA as the active layer exhibited a high p-type mobility over 10(-2) cm(2) indicating its good charge transporting ability. Furthermore, the P3HT-b-PBA(6k) based FET under 100% strain had a high mobility of 2.5 X 10(-2) cm(2) V-1 s(-1) with an on/off ratio of 7.2 X 10(6), and it maintained over 10(-2) cm(2) V-1 s(-1) for 1000 cycles, suggesting the promising stability and reproducbility. The result demonstrated that the newly designed conjugated rod coil block copolymers could have potential applications in stretchable electronic devices.
  • Yusuke Satoh, Hirohiko Matsuno, Takuya Yamamoto, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    MACROMOLECULES 50 1 97 - 106 2017年01月 [査読無し][通常論文]
     
    This paper describes a novel synthetic approach for three- and four-armed cage-shaped polymers based on the topological conversion of the corresponding trefoil- and quatrefoil-shaped precursors. The trefoil- and quatrefoil-shaped polymers were synthesized by the following three reaction steps: (1) the t-Bu-P-4-catalyzed ring-opening polymerization of butylene oxide using multiple hydroxy- and azido-functionalized initiators to produce the three- or four-armed star-shaped polymers possessing three or four azido groups at the focal point, respectively, (2) the omega-end modification to install a propargyl group at each chain end, and (3) the intramolecular multiple click cyclization of the clickable star-shaped precursors. The topological conversion from the trefoil- and quatrefoil-shaped polymers to the cage-shaped polymers was achieved by the catalytic hydrogenolysis of the benzyl ether linkages that had been installed at the focal point. The amphiphilic cage-shaped block copolymers together with the corresponding trefoil- and quatrefoil-shaped counterparts were synthesized in a similar way using 2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether as a hydrophilic monomer and decyl glycidyl ether as a hydrophobic monomer. Interestingly, significant changes in the critical micelle concentration and micellar morphology were observed for the amphiphilic block copolymers upon the topological conversion from the trefoil- and quatrefoil-shaped to cage-shaped architectures.
  • 磯野拓也, 佐藤敏文
    CSJ Current Review 22 204‐205  2016年11月15日 [査読無し][通常論文]
  • Jau-Tzeng Wang, Kengo Saito, Hung-Chin Wu, Han-Sheng Sun, Chih-Chien Hung, Yougen Chen, Takuya Isono, Toyoji Kakuchi, Toshifumi Satoh, Wen-Chang Chen
    NPG ASIA MATERIALS 8 2016年08月 [査読有り][通常論文]
     
    Diblock copolymers consisting of electron-donating poly[2,7-(9,9-dihexylfluorene)] (PF) rods and electron-withdrawing poly (pendent isoindigo) (Piso) coils were designed and synthesized through a click reaction. The electronic properties and interchain organization of the copolymers could be tuned by varying the PF/Piso ratio (PF14-b-Piso(n) (n= 10, 20, 60 and 100)). The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of the studied polymers were progressively reduced as the length of Piso increased, affecting the charge trapping and intramolecular charge transfer environment between PF and Piso domains. Thermally treated PF14-b-Piso(n) thin films exhibited a clear nanofibrillar structure, and the d-spacing was enhanced systematically as the Piso chain length increased. Resistive memory characteristics were explored with a sandwich indium tin oxide/PF14-b-Piso(n)s/Al device configuration. The enhanced conjugated PF conducting channels led to stable resistance switching behavior, exhibiting volatile SRAM (static random access memory) (PF14-b-Piso(10)) and nonvolatile WORM (write-once-read-many-times) (PF14-b-Piso(20), PF14-b-Piso(60), PF14-b-Piso(100)) characteristics with a large ON/OFF ratio (10(6)) and a stable retention time (10(4) s). A more appealing feature is that such memory cells were integrated on a soft poly(dimethylsiloxane) substrate, allowing for the development of a stretchable data storage device. Reliable and reproducible electrical characteristics, including SRAM- and WORM-type memories, could be explored as the device was stretched under an applied tensile strain ranging from 0 to 50%. The studied donor-acceptor copolymers indeed showed great potential for stretchable electronic applications with controllable digital information storage characteristics.
  • WANG Jau‐Tzeng, SAITO Kengo, WU Hung‐Chin, SUN Han‐Sheng, HUNG Chih‐Chien, CHEN Yougen, ISONO Takuya, KAKUCHI Toyoji, SATOH Toshifumi, CHEN Wen‐Chang
    NPG Asia Materials (Web) 8 Aug WEB ONLY  2016年08月 [査読無し][通常論文]
  • Takuya Isono, Kana Miyachi, Yusuke Satoh, Ryosuke Nakamura, Yao Zhang, Issei Otsuka, Kenji Tajima, Toyoji Kakuchi, Redouane Borsali, Toshifumi Satoh
    MACROMOLECULES 49 11 4178 - 4194 2016年06月 [査読無し][通常論文]
     
    This paper describes the systematic investigation into the aqueous self-assembly of a series of block copolymers (BCPs) consisting of maltoheptaose (MH; as the A block) and poly(e-caprolactone) (PCL; as the B block), i.e., linear AB-type diblock copolymers with varied PCL molecular weights (MH-b-PC1-(2.5(k,3.3k,5k10k))), AB(y)-type = 2, MH-b(PCL5k) 2; y = 3, MH-b-(PCL3.3k)(3)), A(2)B(2)-type ((MH)(2)-b(PCL(5)k)(2)), and AxB-type miktoarm star polymers (x = 2, (MH)2-b-PCL10k; x = 3, (MH)(3)-b-PCLiok), which had been precisely synthesized via the combination of the living ring opening polymerization and click reaction. Under similar conditions, the nanoprecipitation method was employed to self -assemble them in an aqueous medium. Imaging and dynamic light scattering techniques indicated the successful formation of the carbohydrate -decorated nanoparticles via self -assembly. The MH-b-PCLs formed regular core shell micellar nanoparticles with the hydrodynamic "radius (Rh) of 17-43 nm. MH-b-(PCL5k)2 and MH-b-(PCL3.3k)(3), which have an NPCL comparable to MH-b-PCLiok, were found to form large compound micelles with relatively large radii (Rh of 49 and 56 nm, respectively). On the other hand, (MH),-b-(PCL5k),, (MH),-b-PCLiok, and (MH)3-bPCLiok predominantly formed the regular core shell micellar nanoparticles (Rh = 29-39 nm) with a size smaller than that of MH-b-PCLiok (Rh = 43 nm).
  • Jau-Tzeng Wang, Shoichi Takashima, Hung-Chin Wu, Yu-Cheng Chiu, Yougen Chen, Takuya Isono, Toyoji Kakuchi, Toshifumi Satoh, Wen-Chang Chen
    ADVANCED FUNCTIONAL MATERIALS 26 16 2695 - 2705 2016年04月 [査読無し][通常論文]
     
    Field-effect transistor memories usually require one additional charge storage layer between the gate contact and organic semiconductor channel. To avoid such complication, new donor-acceptor rod-coil diblock copolymers (P3HT(44)-b-Piso(n)) of poly(3-hexylthiophene)(P3HT)-block-poly(pendent isoindigo) (Piso) are designed, which exhibit high performance transistor memory characteristics without additional charge storage layer. The P3HT and Piso blocks are acted as the charge transporting and storage elements, respectively. The prepared P3HT(44)-b-Piso(n) can be self-assembled into fibrillar-like nanostructures after the thermal annealing process, confirmed by atomic force microscopy and grazing-incidence X-ray diffraction. The lowest-unoccupied molecular orbital levels of the studied polymers are significantly lowered as the block length of Piso increases, leading to a stronger electron affinity as well as charge storage capability. The field-effect transistors (FETs) fabricated from P3HT(44)-b-Piso(n) possess p-type mobilities up to 4.56 x 10(-2) cm(2) V-1 s(-1), similar to that of the regioregular P3HT. More interestingly, the FET memory devices fabricated from P3HT(44)-b-Piso(n) exhibit a memory window ranging from 26 to 79 V by manipulating the block length of Piso, and showed stable long-term data endurance. The results suggest that the FET characteristics and data storage capability can be effectively tuned simultaneously through donor/acceptor ratio and thin film morphology in the block copolymer system.
  • Tsuyoshi TOTANI, Takuya KUNI, Toshifumi SATOH, Takuya ISONO, Masashi WAKITA, Harunori NAGATA
    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 14 ists30 Pi_1 - Pi_6 2016年 [査読有り][通常論文]
  • Yusuke Satoh, Kana Miyachi, Hirohiko Matsuno, Takuya Isono, Kenji Tajima, Toyoji Kakuchi, Toshifumi Satoh
    MACROMOLECULES 49 2 499 - 509 2016年01月 [査読無し][通常論文]
     
    A comprehensive set of amphiphilic star-shaped block copolyethers with a fixed molecular weight and composition was synthesized via the t-Bu-P-4-catalyzed ring opening polymerization (ROP) of 2-(2-(2-methoxyethoxy)-ethoxy)ethyl glycidyl ether as a hydrophilic monomer and decyl glycidyl ether as a hydrophobic monomer. The three and four-armed star-block copolyethers, i.e., the (AB)(3)-, (BA)(3)-, (AB)(4)-, and (BA)(4)-type star-block copolyethers, where A and B represent hydrophilic and hydrophobic blocks, respectively, were synthesized by the sequential t-Bu-P-4-catalyzed block copolymerization using tri- and tetra-alcohol initiators, respectively, according to the core-first method. The homogeneous growth of each arm was confirmed by cleaving the linkages between the initiator residue and polyether arms. The synthesis of the A(2)B(2)-, AB(2)-, and A(2)B-type miktoarm star copolyethers was achieved by the combination of the t-Bu-P-4-catalyzed ROP and azido-alkyne click chemistry. The azido- and ethynyl-functionalized precursor polyethers with the predicted molecular weights were separately prepared by the t-Bu-P-4-catalyzed ROP with the aid of functional initiators as well as a terminator. The intermolecular click reaction of the precursors provided the desired miktoarm star copolyethers. All the obtained star-shaped block copolyethers had a comparable monomer composition (degree of polymerization = 50:50) and total molecular weight (ca. 22 200 g mol(-1)) with a narrow dispersity (<1.05). The hydrodynamic diameter and the cloud point analyses for the aqueous micellar solution of the amphiphilic star-shaped block copolyethers revealed that the self-assembly properties were affected by the block arrangements and branched architectures of the amphiphilic polymers.
  • Han Sheng Sun, Yougen Chen, Wen Ya Lee, Yu Cheng Chiu, Takuya Isono, Toshifumi Satoh, Toyoji Kakuchi, Wen Chang Chen
    Polymer Chemistry 7 6 1249 - 1263 2016年 [査読無し][通常論文]
     
    © The Royal Society of Chemistry 2016.We report the synthesis, morphology, and field effect transistor memory application of maltoheptaose-based block copolymers, maltoheptaose-block-poly(1-pyrenylmethyl methacrylate) (MH-b-PPyMA), and their supramolecules with (4-pyridyl)-acceptor-(4-pyridyl), MH(4Py-Acceptor-4Py)x-b-PPyMA. MH-b-PPyMA was prepared by the combination of the t-Bu-P4-catalyzed group transfer polymerization and the Cu(i)-catalyzed azide-alkyne cycloaddition reaction. After the thermal annealing process, the MH-b-PPyMA bulk sample underwent microphase separation to form the sub-10 nm periodic self-assembled nanostructure. The self-assembled morphologies transform from the hexagonal cylinder packing to the body-centered cubic sphere arrangement and the disordered spherical nanodomain with the increase of the PPyMA segment length. On the contrary, only the spherical nanodomain was observed in the thermo-annealed thin film samples of both MH-b-PPyMA and MH(4Py-Acceptor-4Py)x-b-PPyMA. The electrical characteristics of the p-type pentacene-based OFET memory device were studied using the thermo-annealed polymer thin film as the electret layer. The MH(4Py-Acceptor-4Py)x-b-PPyMA-based organic field effect transistor (OFET) devices had the high hole mobility of 0.20-1.08 cm2 V-1 s-1 and the ON/OFF current (ION/IOFF) ratio of 107-108, in which the acceptor of the benzo[c][1,2,5]thiadiazole (BT) based device possessed the higher hole mobility than that of the isoindigo-based one due to the more ordered packing pentacene crystals. The memory window (ΔVTH) of the supramolecule-based device was increased with enhancing the 4Py-Acceptor-4Py blending composition, and that of the MH(4Py-BT-4Py)1.5-b-PPyMA10-based device had the largest ΔVTH of ca. 9 V, a long-term retention time greater than 104 s and the high ION/IOFF memory ratio of 106-107 (reading at Vg = 0 V) for more than 100 programming/erasing cycles. Our results demonstrate that the bio-related block copolymers and their supramolecular thin film could be used as electret layers for high-performance nonvolatile flash green memory devices.
  • Kodai Watanabe, Ryoto Tanaka, Kenji Takada, Myung-Jin Kim, Jae-Suk Lee, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    POLYMER CHEMISTRY 7 29 4782 - 4792 2016年 [査読無し][通常論文]
     
    A comprehensive examination of the synthesis of single-chain nanoparticles (SCNPs) from statistical copolymers of n-butyl methacrylate (BMA) and 3-butenyl methacrylate (3BMA), i.e., P(BMA-co-3BMA)s, via the intramolecular olefin metathesis reaction under high dilution conditions is described. The olefin metathesis reaction of P(BMA-co-3BMA) using Grubbs' 2nd generation catalyst in CH2Cl2 efficiently gave the corresponding SCNPs under mild conditions. We achieved the size-controlled synthesis of the SCNPs by adjusting the following factors: (1) the olefin content in the precursor, (2) the molecular weight of the precursor, and (3) the solvent quality of the reaction medium. The hydrodynamic radius and the intrinsic viscosity of the resultant SCNPs were investigated by DLS and viscometric measurements, respectively, which provided further evidence of SCNP formation with controlled diameters. Furthermore, the above-established intramolecular olefin metathesis approach was successfully applied to poly(acrylate), poly(styrene), and poly(ester) precursors, which proved that the present approach could be applied to a wide range of olefin-containing precursors to give SCNPs with various functional groups.
  • Hikaru Yanai, Osamu Kobayashi, Kenji Takada, Takuya Isono, Toshifumi Satoh, Takashi Matsumoto
    CHEMICAL COMMUNICATIONS 52 16 3280 - 3283 2016年 [査読有り][通常論文]
     
    In the presence of a strong carbon acid, the sequential Mukaiyama-Michael reaction using two different Michael acceptors proceeded and the reaction of ketene silyl acetal derived from EtOAc with alpha-pyrones as primal acceptors yielded the corresponding cyclic ketene silyl acetals, which were reactive enough to undergo the following reaction with second acceptors.
  • 國拓也, 戸谷剛, 佐藤敏文, 磯野拓也, 脇田督司, 永田晴紀
    熱物性 29 4 173 - 178 2015年11月30日 [査読無し][通常論文]
  • Rarm Phinjaroenphan, Young Yong Kim, Brian J. Ree, Takuya Isono, Jinseok Lee, Supagorn Rugmai, Heesoo Kim, Santi Maensiri, Toyoji Kakuchi, Toshifumi Satoh, Moonhor Ree
    MACROMOLECULES 48 16 5816 - 5833 2015年08月 [査読無し][通常論文]
     
    Two series of crystalline-crystalline miktoarm star polymers were prepared and their thin film morphologies were investigated in detail by synchrotron grazing incidence X-ray scattering (GIXS): poly(n-hexyl isocyanate)(5000) poly(epsilon-caprolactone) (1-3)(17000) (PHIC(5k)-PCL1-3(17k)) and poly(n-hexyl isocyanate) (10000) poly(epsilon-caprolactone)(1-3)(10000) (PHIC(10k)-PCL1-3(10k)). In addition, their thermal properties were examined. All miktoarm star polymers revealed a two-step thermal degradation behavior where the PHIC arm was degraded first, followed by the PCL arm underwent degradation. Interestingly, all miktoarms were found to show a highly enhanced thermal stability, regardless of their molecular weight over 3k to 17k, which might be attributed to their one-end group capped with the counterpart arm(s) via arm-joint formation. Surprisingly, all miktoarm star polymers always developed only lamellar structure in toluene- and chloroform-annealed films via phase-separation, regardless of the length of PHIC arm as well as the length and number of PCL arm. Despite having highly imbalanced volume fractions, lamellar structure was constructed in the films of miktoarm star polymers through the override of volume fraction rule based on the rigid chain properties, self-assembling characteristics, conformational asymmetry, and compressibilities of PHIC and PCL arms. Furthermore, the orientation of such lamellar structures was controlled by the selection of either toluene or chloroform in the solvent-annealing process. The PHIC arm phases in the lamellar structures favorably formed a mixture of edge-on and face-on structures with fully extended backbone and bristle conformations even under the confined lamellar geometry and arm-joint. The PCL arm phases still crystallized, forming fringed-micelle like structures in which orthorhombic crystals were laterally grown along the in-plane direction of lamellae although their crystallization was somewhat suppressed by the confined lamellar geometry and arm-joint. Overall, crystalline-crystalline PHIC-PCL1-3 miktoarm polymers demonstrated very interesting but unusual, very complex hierarchical structures in the solvent-annealed thin films.
  • Takuya Isono, Shunsuke Asai, Yusuke Satoh, Toshimitsu Takaoka, Kenji Tajima, Toyoji Kakuchi, Toshifumi Satoh
    MACROMOLECULES 48 10 3217 - 3229 2015年05月 [査読無し][通常論文]
     
    The combination of t-Bu-P-4 and alcohol was found to be an excellent catalytic system for the controlled/living ring-opening polymerization (ROP) of N,N-disubstituted glycidylamine derivatives, such as N,N-dibenzylglycidylamine (DBGA), N-benzyl-N-methylglycidylamine, N-glycidylmorpholine, and N,N-bis(2-methoxyethyl)glycidylamine, to give well-defined polyethers having various pendant tertiary amino groups with predictable molecular weights and narrow molecular weight distributions (typically M-w/M-n, < 1.2). The tBu-P-4-catalyzed ROP of these monomers in toluene at room temperature proceeded in a living manner, which was confirmed by a MALDI-TOF MS analysis, kinetic measurement, and postpolymerization experiment. The well-controlled nature of the present system enabled the production of the block copolymers composed of the glycidylamine monomers. The polyethers having pendant primary and secondary amino groups, i.e., poly(glycidylamine) and poly(glycidylmethylamine), respectively, were readily obtained by the debenzylation of poly(DBGA) and poly(BMGA), respectively, through the treatment with Pd/C in THF/MeOH under a hydrogen atmosphere. To the best of our knowledge, this report is the first example of the controlled/living polymerization of glycidylamine derivatives, providing a rapid and comprehensive access to the polyethers having primary, secondary, and tertiary amino groups.
  • Issei Otsuka, Yao Zhang, Takuya Isono, Cyrille Rochas, Toyoji Kakuchi, Toshifumi Satoh, Redouane Borsali
    MACROMOLECULES 48 5 1509 - 1517 2015年03月 [査読無し][通常論文]
     
    The present paper describes the sub-10 nm scale self-assembly of AB-type diblock, ABA-type triblock, and A(2)B-type miktoarm star copolymers consisting of maltoheptaose (MH: A block) and polystyrene (PS: B block). These block copolymers (BCPs) were synthesized through coupling of end-functionalized MH and PS moieties. Small-angle X-ray scattering and atomic force microscope investigations indicated self-organized cylindrical and lamellar structures in the BCP bulks and thin films with domain spacing (d) ranging from 7.65 to 10.6 nm depending on the volume fraction of MH block (phi(MH)), Flory-Huggins interaction parameter (chi), and degree of polymerization (N). The BCP architecture also governed the morphology of the BCPs, e.g. the AB-type diblock copolymer (phi(MH) = 0.42), the ABA-type triblock copolymer (phi(MH) = 0.40), and the A2B-type miktoarm star copolymer (phi(MH) = 0.45) self-organized into cylinder (d = 7.65 nm), lamellar (d = 8.41 nm), and lamellar (d = 9.21 nm) structures, respectively.
  • 磯野拓也, 佐藤悠介, 覚知豊次, 佐藤敏文
    高分子論文集 72 5 295 - 305 2015年 [査読無し][通常論文]
     
    This comprehensive paper describes the anionic ring-opening polymerization of substituted epoxides using a phosphazene base catalyst, t-Bu-P-4, and its application for the synthesis of architecturally complex polyethers. The t-Bu-P-4-catalyzed ROP of 1,2-butylene oxide (BO) produced the poly(BO) having the predicted molecular weight and narrow polydispersity. The kinetic analysis revealed that the ROP system proceeded in a living manner. The t-Bu-P(4)catalyzed ROP was then applied to the polymerization of various epoxides having a variety of side chains, e.g. styrene oxide. The synthesis of star-shaped polyethers was achieved by the t-Bu-P-4-catalyzed ROP using polyols as an initiator. The syntheses of cyclic-, figure-eight-shaped, and tadpole-shaped polyethers were also achieved via the intramolecular click reaction of the well-defined linear precursors bearing azido and ethynyl functions at designed positions.
  • Yougen Chen, Kenji Takada, Naoya Kubota, Ofosu-Twum Eric, Takahiro Ito, Takuya Isono, Toshifumi Satoh, Toyoji Kakuchi
    POLYMER CHEMISTRY 6 10 1830 - 1837 2015年 [査読無し][通常論文]
     
    The present study describes the alpha- and omega-end-functionalization of poly(methyl methacrylate)s (PMMAs) by organocatalyzed group transfer polymerization (GTP) using both functional silyl ketene acetal (SKA) initiators and alpha-phenylacrylate terminators. The syntheses of structurally defect-free alpha-end-functionalized PMMAs with hydroxyl, ethynyl, vinyl, and norbornenyl groups (HO-PMMA, HC C-PMMA, H2C CH-PMMA, and NB-PMMA, respectively) were achieved by either the N-(trimethylsilyl)bis(trifluoromethanesulfonyl)imide-( Me3SiNTf2-) or t-Bu-P-4-catalyzed GTP of MMA using functional trimethyl SKAs (1a-1d). On the other hand, the omega-end-functionalized PMMAs with ethynyl, hydroxyl, vinyl, and bromo groups (PMMA-C CH, PMMA-OH, PMMA-CH CH2, and PMMA-Br, respectively) were for the first time obtained by the Me3SiNTf2-catalyzed GTP of MMA followed by a termination reaction using functional alpha-phenylacrylates (2a-2d). All the polymerizations produced end-functionalized PMMAs with controlled molar masses, narrow dispersities, and defect-free polymer structures as designed. The quantitative incorporation of functionalities into the alpha- or omega-end of the PMMAs was confirmed by the H-1 NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) measurements.
  • Tatsuya Saito, Yusuke Aizawa, Kenji Tajima, Takuya Isono, Toshifumi Satoh
    POLYMER CHEMISTRY 6 24 4374 - 4384 2015年 [査読無し][通常論文]
     
    The ring-opening polymerizations (ROPs) of epsilon-caprolactone (epsilon-CL), delta-valerolactone, 1,5-dioxepan-2-one, trimethylene carbonate, and L-lactide were performed in the bulk using an organophosphate, such as diphenyl phosphate, bis(4-nitrophenyl)phosphate, and di(2,6-xylyl)phosphate, as the catalyst. The ROPs proceeded in a well-controlled manner even under the bulk conditions to afford well-defined aliphatic polyesters, polyester-ether, and polycarbonate with relatively low dispersities. Notably, the amount of the loaded catalyst was successfully reduced when compared to the conventional organophosphate-catalyzed ROP in solution. A kinetic study revealed the controlled/living nature of the present bulk ROP system, which allowed us to produce the block copolymers composed of polyesters, polyester-ether, and polycarbonate in one pot. Syntheses of the end-functionalized poly(epsilon-caprolactone)s (PCLs) and poly(trimethylene carbonate) were successfully demonstrated using alcohol initiators possessing highly reactive functional groups. Furthermore, the alpha,beta-dihydroxy telechelic PCL-diol as well as the three-and fourarmed star-shaped PCL-polyols were also easily obtained by using the polyols as an initiator. Finally, the one-pot synthesis of polyurethane via the ROP of epsilon-CL and a subsequent urethane forming reaction was demonstrated by taking advantage of the dual catalytic abilities of the organophosphate for both the ROP and polyurethane synthesis.
  • Kengo Saito, Takuya Isono, Han-Sheng Sun, Toyoji Kakuchi, Wen-Chang Chen, Toshifumi Satoh
    POLYMER CHEMISTRY 6 39 6959 - 6972 2015年 [査読無し][通常論文]
     
    A series of rod-coil miktoarm star copolymers consisting of poly[2,7-(9,9-dihexylfluorene)] (PF) and polylactide (PLA) arms as the rod and coil segments, respectively, were synthesized by combining the chain-growth Suzuki-Miyaura coupling polymerization and living ring-opening polymerization (ROP). First, PFs having a hydroxyl group at the alpha-chain end (PF-BnOH) were prepared by the polymerization of 2-(7-bromo-9,9-dihexyl-9H-fluorene-2-yl) 4,4,5,5-tetramethyl-1,2,3-dioxaborolane using the initiating system of 4-(tetrahydropyran-2'-yloxymethyl)-iodobenzene/Pd-2(dba)(3)/t-Bu3P. After a couple of chain end modifications, PFs having one, two, and three hydroxyl groups at the alpha-chain end (PF-OH, PF-(OH)(2), and PF-(OH)(3), respectively) were obtained with dispersity (D) values of less than 1.29. The obtained PF-OH, PF-(OH)(2), and PF-(OH)(3) were used as the initiators for the organic base-catalyzed ROP of rac-lactide to produce the AB type linear diblock (PF-b-PLA) and AB(2) and AB(3) type miktoarm star copolymers (PF-b-(PLA)(2) and PF-b-(PLA)(3), respectively). The self-assembled nanostructures in the thermally-annealed PF-b-(PLA)(x)s (x = 1, 2, and 3) were evaluated in the bulk by synchrotron small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The PF-b-PLA, PF-b-(PLA)(2), and PF-b-(PLA)(3) with the PF weight fractions of 0.52-0.56 were found to form poorly ordered PLA cylindrical structures in the PF matrix due to a strong rod-rod interaction of the PF segment. On the other hand, these BCPs with the PF weight fractions of 0.22-0.23 exhibited the hexagonally close-packed cylinder (Hex) morphologies, in which the cylindrical PF phase was embedded in the PLA matrix. More interestingly, the domain-spacing (d) values for the Hex morphologies decreased with the increasing PLA arm number despite each BCP having a comparable molecular weight and PF weight fraction: d = 26.4 nm for PF-b-PLA, d = 21.7 nm for PF-b-(PLA)(2), and d = 18.6 nm for PF-b-(PLA)(3).
  • Young Yong Kim, Sungmin Jung, Changsub Kim, Brian J. Ree, Daisuke Kawato, Naoki Nishikawa, Daichi Suemasa, Takuya Isono, Toyoji Kakuchi, Toshifumi Satoh, Moonhor Ree
    MACROMOLECULES 47 21 7510 - 7524 2014年11月 [査読無し][通常論文]
     
    A series of miktoarm star polymers, [poly(n-hexyl isocyanate)(12K)][poly(epsilon-caprolactone)(13)(5K)] (PHICPCL13) (composed of a rigid self-assembling PHIC arm and one to three flexible crystallizable PCL arms), were investigated to examine the polymers thermal properties and nanoscale thin film morphologies. The miktoarm polymers were stable up to 180 degrees C. The PHIC and PCL arm components underwent phase separation during the solution casting, drying, and post toluene-annealing processes, forming interesting but very complex thin film morphologies. The resulting thin film morphologies were examined in detail for the first time using synchrotron grazing incidence X-ray scattering (GIXS) measurements and quantitative data analysis. All of the miktoarm star polymer films formed vertically well-oriented lamellar structures, regardless of the number and length of PCL arms. These structures were quite different from the cylindrical structures commonly observed in conventional flexible diblock copolymer films having comparable volume fractions. The individual PHIC and PCL lamellar domains self-assembled to form their own respective morphological structures. The PHIC lamellae consisted of a mixture of horizontal and vertical multibilayer structure domains, as observed in the PHIC homopolymer film. The PCL lamellae formed fringed micelle-like crystals and/or highly imperfect folded crystals that differed significantly from the structures found in a PCL homopolymer film composed of typical folded lamellar crystals. These PCL crystals were formed with a mixture of vertical and horizontal orthorhombic lattices. Overall, the GIXS analysis revealed that the parameters that characterized the hierarchical structures in the thin films depended significantly on the number and length of the PCL arm and its crystallization characteristics as well as the chain rigidity and multibilayer structure formation characteristics of the PHIC arm.
  • Rarm Phinjaroenphan, Young Yong Kim, Sungmin Jung, Takuya Isono, Yusuke Satoh, Santi Maensiri, Supagorn Rugmai, Toyoji Kakuchi, Toshifumi Satoh, Moonhor Ree
    SCIENCE OF ADVANCED MATERIALS 6 11 2526 - 2531 2014年11月 [査読無し][通常論文]
     
    The nanoscale thin film morphologies of a series of interesting miktoarm star polymers composed of a highly rigid and crystallizable poly(n-hexyl isocyanate) (PHIC) arm and one to three flexible and crystallizable poly(epsilon-caprolactone) (PCL) arms were investigated using synchrotron grazing incidence X-ray scattering methods. Nanoscale thin films of a PHIC and a PCL homopolymer were also characterized for comparison. The PCL homopolymer and star polymers formed horizontally oriented lamellar structures in toluene-annealed films. The horizontal lamellar structures formed in the miktoarm star polymer films were quite different from those observed in common flexible block copolymer specimens. Interestingly, the structural parameters associated with the star polymer films were significantly influenced by the exceptional rigidity of the PHIC arm chain and by the number and length of the PCL arms. This study demonstrated that a miktoarm star polymer system consisting of rigid and crystallizable arms could form thin films with a morphology that is suitable for specific target applications.
  • Takuya Isono, Yohei Kondo, Shun Ozawa, Yougen Chen, Ryosuke Sakai, Shin-ichiro Sato, Kenji Tajima, Toyoji Kakuchi, Toshifumi Satoh
    MACROMOLECULES 47 20 7118 - 7128 2014年10月 [査読無し][通常論文]
     
    Random and block copolymerizations of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) macromonomers having an exo-norbornene group at the alpha- or pi-chain end (D/L ratio = 1/1, M-n = ca. 5000 g mol(-1)) were performed via ring-opening metathesis polymerization to produce the brush random and block copolymers consisting of parallel or antiparallel aligned PLLA and PDLA side chains on a poly(norbornene) backbone. The molecular weight and polydispersity index of the brush copolymers were in the range of 40 300-458 000 g mol(-1) and 1.031.14, respectively. Despite such high molecular weights, these brush copolymers formed a stereocomplex without homochiral crystallization. The melting temperature (T-m) and crystallinity (X) of the resulting stereocomplex varied depending on the backbone length, relative chain direction, and distribution of the PLLA/PDLA side chains. The parallel brush copolymers showed significantly higher T-m and X values than the antiparallel ones.
  • Takuya Isono, Yusuke Satoh, Kana Miyachi, Yougen Chen, Shin-ichiro Sato, Kenji Tajima, Toshifumi Satoh, Toyoji Kakuchi
    MACROMOLECULES 47 9 2853 - 2863 2014年05月 [査読無し][通常論文]
     
    This paper describes the synthesis of systematic sets of figure-eight- and tadpole-shaped amphiphilic block copolyethers (BCPs) consisting of poly(decyl glycidyl ether) and poly[2-(2-(2-methoxyethoxy)ethoxy)ethyl glycidyl ether], together with the corresponding cyclic counterparts, via combination of the t-Bu-P-4-catalyzed ring-opening polymerization (ROP) and click cyclization. The clickable linear BCP precursors, with precisely controlled azido and ethynyl group placements as well as a fixed molecular weight and monomer composition (degree of polymerization for each block was adjusted to be around 50), were prepared by the t-Bu-P-4-catalyzed ROP with the aid of functional initiators and terminators. The click cyclization of the precursors under highly diluted conditions produced a series of cyclic, figure-eight-, and tadpole-shaped BCPs with narrow molecular weight distributions of less than 1.06. Preliminary studies of the BCPs self-assembly in water revealed the significant variation in their cloud points depending on the BCP architecture, though there were small architectural effects on their critical micelle concentration and morphology of the aggregates.
  • Takuya Isono, Yohei Kondo, Issei Otsuka, Yoshiharu Nishiyama, Redouane Borsali, Toyoji Kakuchi, Toshifumi Satoh
    MACROMOLECULES 46 21 8509 - 8518 2013年11月 [査読無し][通常論文]
     
    The synthesis of star-shaped polylactides (PLAs) having both poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) arms in one molecule, i.e., stereo-miktoarm star-shaped PLAs, is described. The azido-functionalized PDLAs and ethynyl-functionalized PLLA possessing linear and two- and three-branched structures were prepared by the ring-opening polymerization of D-lactide and L-lactide using azido- or ethynyl-functionalized initiators. The number-average molecular weights (M(n,NMR)s) of the PLAs were ca. 5000 g, mol(-1) with narrow molecular weight distributions (M-w/M(n)s) of less than 1.18. The click reaction of the azido-functionalized PDLAs and the ethynyl-functionalized PLLAs using the copper(I) bromide/N,N,N',N '',N ''-pentamethyldiethylenetriamine catalyst in a mixed solvent of dichloromethane/1,1,1,3,3,3-hexafluoro-2-propanol (14/1, v/v) gave a linear stereoblock PLA as well as 3-, 4-, 5-, and 6-armed stereo-miktoarm star-shaped PLAs with M(n,NMR)s of ca. 10 000 g mol(-1) and M-w/M(n)s of less than 1.16. The wide-angle X-ray scattering and differential scanning calorimetry measurements proved that these stereo-miktoarm star-shaped PLAs formed stereocomplex crystals without any trace of homochiral crystallization.
  • Takuya Isono, Issei Otsuka, Daichi Suemasa, Cyrille Rochas, Toshifumi Satoh, Redouane Borsali, Toyoji Kakuchi
    MACROMOLECULES 46 22 8932 - 8940 2013年11月 [査読無し][通常論文]
     
    Three different self-assembled nanostructures, i.e., lamellar (Lam), hexagonally close-packed cylinder (Hex), and body-centered cubic (BCC), have been obtained from ABA triblock (MH-b-PCL-b-MH) and A(2)B star-branched copolymers ((MH)(2)-b-PCL) consisting of maltoheptaose (MH, as the A block) and polycaprolactone (PCL, as the B block). MH-b-PCL-b-MH and(MH)(2)-b-PCL were synthesized by the click reaction of the alpha,omega-diazido and alpha,alpha-diazido end-functionalized PCLs with N-maltoheptaosyl-3-acetamido-1-propyne in high yields. The self-assembled nanostructures of the block copolymers (BCPs) in bulk were investigated as a function of temperature by time-resolved small-angle X-ray scattering using a synchrotron light source. The SAXS analysis revealed that the obtained BCPs exhibited microphase-separated structures with the domain-spacing of 10.4-21.0 nm. MH-b-PCL-b-MH (the MH volume fraction (phi(MH)) of 0.28 and 0.15) exhibited a hexagonally close-packed cylinder (Hex) at below ca. 230 degrees C, and the self-assembling behavior of MH-b-PCL-b-MH was essentially the same as that of the diblock counterpart, MH-b-PCL, having comparable phi(MH) values. The lamellar (Lam) morphology, which was unattainable from the corresponding linear counterparts, was observed from (MH)(2)-b-PCL (phi(MH) = 0.27 and 0.16). Furthermore, the microphase transitions from the Hex into the body-centered cubic sphere and the Lam into the Hex were observed upon the thermal caramelization of the MH block.
  • Takuya Isono, Kensuke Kamoshida, Yusuke Satoh, Toshimitsu Takaoka, Shin-Ichiro Sato, Toshifumi Satoh, Toyoji Kakuchi
    Macromolecules 46 10 3841 - 3849 2013年05月28日 [査読無し][通常論文]
     
    The synthesis of well-defined four-armed star-shaped poly(butylene oxide) and figure-eight-shaped poly(butylene oxide)s (s-PBO and 8-PBO, respectively) with predicted molecular weights and narrow molecular weight distributions (Mw/Mns) was achieved by the t-Bu-P4-catalyzed ring-opening polymerization (ROP) of butylene oxide (BO). The t-Bu-P 4-catalyzed ROP of BO using 1,2,4,5-benzenetetramethanol as the initiator produced s-PBOs having number-average molecular weights (M n,NMRs) ranging from ca. 4000 to 12 000 g mol-1 and narrow Mw/Mns of < 1.03. Cleavage of the linkage between the initiator residue and PBO arms in s-PBO provided evidence for the homogeneous growth of each arm during the polymerization. The synthesis of 8-PBO was carried out through three reaction steps including (1) the synthesis of a PBO possessing two azido groups at the chain center ((N3) 2-(PBO)2) by the ROP of BO using 2,2-bis((6-azidohexyloxy) methy)propane-1,3-diol as the initiator, (2) the introduction of an ethynyl group at the two ω-chain ends by etherification using propargyl bromide to give the ω,ω′-diethynyl poly(butylene oxide) with two azido groups ((N3)2-(PBO-C≡CH)2), and (3) the intramolecular click cyclization of (N3)2-(PBO-C≡CH) 2 using the copper(I) bromide/N,N,N′,N″,N″- pentamethyldiethylenetriamine catalyst in DMF under high dilution conditions. Size exclusion chromatography, FT-IR, and 1H NMR measurements confirmed that the click reaction proceeded in an intramolecular fashion to give 8-PBOs having Mn,NMRs ranging from ca. 3000 to 12 000 g mol -1 and narrow Mw/Mns of < 1.06. The viscosity property of s-PBO and 8-PBO was evaluated together with linear and cyclic PBOs (l-PBO and c-PBO, respectively). The intrinsic viscosity ([η]) of l-PBO, c-PBO, s-PBO, and 8-PBO decreased in the order of l-PBO > s-PBO > c-PBO > 8-PBO. © 2013 American Chemical Society.
  • Takuya Isono, Issei Otsuka, Yohei Kondo, Sami Halila, Sebastien Fort, Cyrille Rochas, Toshifumi Satoh, Redouane Borsali, Toyoji Kakuchi
    MACROMOLECULES 46 4 1461 - 1469 2013年02月 [査読無し][通常論文]
     
    The AB(2)- and AB(3)-type miktoarm star copolymers consisting of maltoheptaose (MH, as A block) and poly(epsilon-caprolactone) (PCL, as B block), namely MH-b-(PCL)(2) and MH-b-(PCL)(3), were synthesized, and their nano-organization was characterized. The syntheses of MHb-(PCL)(2) and MH-b-(PCL)(3) were carried out through two reaction steps: (1) preparation of linear and three-branched PCLs bearing an azido group on the chain center (N-3-(PCL)(2) and N-3-(PCL)(3)) by the diphenyl phosphate-catalyzed ring-opening polymerization of epsilon-caprolactone (epsilon-CL) using azido-functionalized di- and triols (N-3-(OH)(2) and N-3-(OH)(3)) as the initiators and (2) the copper-catalyzed azide-alkyne cycloaddition of N-3-(PCL)(2) and N-3-(PCL)(3) with the ethynyl-functionalized MH. The miktoarm star copolymers having M-n for the PCL block of ca. 5000 (MH-b-(PCL2.5k)(2) and MH-b-(PCL1.7k)(3)) and 10 000 (MH-b-(PCL5k)(2) and MH-b-(PCL3.3k)(3)) were obtained with a very narrow polydispersity index of less than 1.05. Bulk samples of the four types of miktoarm star copolymers exhibited body centered cubic phases, as determined by small angle X-ray diffraction experiments. The domain spacing were determined to be 9.8 nm for MH-b-(PCL2.5k)(2), 8.8 nm for MH-b-(PCL1.7k)(3), 10.5 nm for MH-b-(PCL5k)(2), and 9.8 nm for MH-b-(PCL3.3k)(3), which were smaller than those of the corresponding linear diblock copolymers.
  • Issei Otsuka, Takuya Isono, Cyrille Rochas, Sami Halila, Sebastien Fort, Toshifumi Satoh, Toyoji Kakuchi, Redouane Borsali
    ACS MACRO LETTERS 1 12 1379 - 1382 2012年12月 [査読有り][通常論文]
     
    To date, the feature size of microphase separation in block copolymers has been downsizing to 10 nm scale. However, morphological control for such a small feature is still a challenging task. The present Letter discusses a phase transition in a natural/synthetic "hybrid" block copolymer system based on an oligosaccharide and poly(e-caprolactone) via thermal annealing. Time-resolved small-angle X-ray scattering investigation as a function of temperature indicated the phase transition from hexagonally close-packed cylinder to body-centered cubic at 10 am scale. Atomic force microscope images of the block copolymer thin films annealed at different temperatures clearly confirmed the existence of these morphologies. The driving force of this phase transition (from cylinder to cubic) is the change of volume fraction of the block copolymer due to thermal caramelization.
  • Takuya Isono, Toshifumi Satoh, Toyoji Kakuchi
    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY 49 14 3184 - 3192 2011年07月 [査読無し][通常論文]
     
    The one-pot synthesis of a main chain-type polyrotaxane composed of axle molecules threaded through the macrocyclic units on the polymer main chain was achieved via the combination of cyclopolymerization and clipping procedures. The cyclopolymerization of an a, x-diethynyl monomer bearing an isophthalamide moiety (1), which clips onto an axle component bearing a pyridiniumdicarboxamide moiety (2 center dot Cl) through a chloride anion was carried out in chloroform with the monomer concentration of 0.06 mol L-1 at 40 degrees C using [Rh(nbd)Cl](2)/Et3N as a catalyst to afford a gel-free polymer. The resulting polymer was assigned to the main chain-type polyrotaxane with a poly(phenylacetylene) backbone (poly-3 center dot Cl) based on size exclusion chromatography and H-1 NMR measurements. The diffusion-order two-dimensional NMR and circular dichroism spectra provided definitive proof of the rotaxaned architecture in the polymer. The mole fraction of the rotaxane unit in the total cyclic repeating unit was determined to be 26.3%. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3184-3192, 2011

MISC

書籍等出版物

  • 環状高分子の合成と機能発現
    磯野 拓也, 佐藤 敏文 (担当:分担執筆範囲:有機分子触媒とクリック反応の組み合わせによる両親媒性環状ブロック共重合体の合成)
    シーエムシー出版 2018年12月
  • 構造制御による革新的ソフトマテリアル創成
    磯野 拓也, 佐藤 敏文 (担当:分担執筆範囲:開環重合を用いたブロック共重合体の合成)
    化学同人 2018年05月
  • 有機分子触媒の開発と工業利用
    磯野 拓也, 佐藤 敏文 (担当:分担執筆範囲:有機触媒重合を活用した機能性高分子材料の開発)
    シーエムシー出版 2018年03月
  • 有機分子触媒の化学-モノづくりのパラダイムシフト
    磯野 拓也, 佐藤 敏文 (担当:分担執筆範囲:ポリマー合成への応用)
    化学同人 2016年11月
  • Encyclopedia of Polymeric Nanomaterials
    磯野 拓也 (担当:分担執筆範囲:Poly(cyclic olefin)s)
    Springer 2015年06月

講演・口頭発表等

担当経験のある科目(授業)

  • 英語演習(中級:化学系に求められる英語力を身につける)北海道大学
  • 機能性高分子特論北海道大学
  • 化学英語北海道大学
  • 応用化学学生実験V北海道大学
  • 高分子化学I北海道大学

所属学協会

  • 日本化学会   高分子学会   日本ゴム協会   

共同研究・競争的資金等の研究課題

  • 超精密・超微細ナノ加工を指向した単分散ブロックポリマーの創製
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2020年04月 -2023年03月 
    代表者 : 磯野 拓也
  • 電着樹脂含浸法を用いたCFRPのラティス構造の製造法とその応用基盤技術の開発
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2020年04月 -2023年03月 
    代表者 : 片桐 一彰
  • 脂肪族ポリエステルの実践的合成を目指した高活性固定化触媒の開発
    豊田理研スカラー共同研究
    研究期間 : 2021年04月 -2022年09月
  • 糖類/生分解ポリマー複合体に関する応用研究
    企業との共同研究
    研究期間 : 2020年02月 -2022年03月
  • 超高アスペクト比ナノセルロースのネットワーク構造を活用した抗がん剤の効率的な送達
    日本学術振興会:基盤研究(B)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 田島 健次
  • シングルナノサイズのミクロ相分離構造を実現するブロック共重合体デザイン
    日本学術振興会:基盤研究(B)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 佐藤 敏文
  • 糖鎖セグメントの導入を鍵とする高付加価値バイオベースポリマーの設計
    豊田理化学研究所:豊田理研スカラー
    研究期間 : 2020年04月 -2021年03月
  • 高分子鎖からなるソフトな巨大カゴ状分子システムの構築
    日本学術振興会:挑戦的研究(萌芽)
    研究期間 : 2019年06月 -2021年03月 
    代表者 : 佐藤 敏文
  • 植物原料由来ブロック共重合体の自己組織化を利用した微細構造炭素材料の精密合成
    旭硝子財団:2019年度旭硝子財団研究奨励
    研究期間 : 2019年04月 -2021年03月 
    代表者 : 磯野 拓也
  • シングルナノスケールの微細加工を可能にする超強偏斥ブロック共重合体の開発
    池谷科学技術振興財団:2019年度 単年度研究助成
    研究期間 : 2019年04月 -2020年03月 
    代表者 : 磯野 拓也
  • 単分散糖鎖ブロック共重合体によるシングルナノミクロ相分離構造の戦略的構築
    日本学術振興会:若手研究
    研究期間 : 2018年04月 -2020年03月 
    代表者 : 磯野 拓也
  • 糖とテルペンからなるハイブリッド材料を用いたシングルナノ構造体の構築
    松籟科学技術振興財団:
    研究期間 : 2018年03月 -2020年03月 
    代表者 : 磯野 拓也
  • 特殊構造ブロック共重合体による微細構造化技術の開発
    日本学術振興会:基盤研究(B)
    研究期間 : 2016年04月 -2019年03月 
    代表者 : 佐藤 敏文
  • 有機酸塩:次世代の脂肪族ポリエステル合成触媒システム
    稲盛財団:研究助成
    研究期間 : 2017年04月 -2018年03月 
    代表者 : 磯野 拓也
  • 植物由来炭化水素をベースとしたシングルナノ自己組織化材料の分子設計
    東燃ゼネラル石油研究奨励・奨学財団:研究奨励助成
    研究期間 : 2017年04月 -2018年03月 
    代表者 : 磯野 拓也
  • 連鎖的環形成:多環状高分子合成の新展開
    日本学術振興会:挑戦的萌芽研究
    研究期間 : 2016年04月 -2018年03月 
    代表者 : 佐藤 敏文
  • 細孔表面が糖鎖で修飾された機能性高分子ナノポーラス材料の開発
    小笠原科学技術振興財団:
    研究期間 : 2016年04月 -2017年03月 
    代表者 : 磯野 拓也
  • 分子内架橋構造を有するブロック共重合体の精密合成と自己組織化ナノ構造制御への応用
    学術振興会:若手研究(B)
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 磯野 拓也
  • 生分解性高分子からなるナノ構造材料の精密調製法
    日本学術振興会:基盤研究(B)
    研究期間 : 2013年04月 -2016年03月 
    代表者 : 佐藤 敏文
  • リビング重合法を基盤とした単分子ポリマーナノパーティクルの精密設計
    学術振興会:研究活動スタート支援
    研究期間 : 2014年08月 -2015年03月 
    代表者 : 磯野 拓也
  • オリゴ糖含有ブロック共重合体による環境調和型ナノ粒子の創出
    ノーステック財団:若手研究人材・ネットワーク育成補助金
    研究期間 : 2014年08月 -2015年03月 
    代表者 : 磯野 拓也
  • 多環状ポリマーの新規精密合成法の開発
    日本学術振興会:挑戦的萌芽研究
    研究期間 : 2013年04月 -2015年03月 
    代表者 : 佐藤 敏文
  • 主鎖上に刺激応答性ロタキサン構造を有するポリアセチレンの精密合成と機能開発
    学術振興会:特別研究員奨励費
    研究期間 : 2012年04月 -2014年08月 
    代表者 : 磯野 拓也


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