Researchers Database

KUROSU Hiromichi

    Vice President Vice President
    Faculty Division of Engineering Research Group of Engineering Professor
Contact:
kurosucc.nara-wu.ac.jp
Last Updated :2021/06/18

researchmap

Degree

  • Doctor of Engineering, Tokyo Institute of Technology

Research Areas

  • Life sciences, Structural biochemistry
  • Nanotechnology/Materials, Polymer materials
  • Humanities & social sciences, Home economics, lifestyle science
  • Humanities & social sciences, Home economics, lifestyle science

Research Experience

  • Apr. 2012, 奈良女子大学研究院生活環境科学系衣環境学領域領域・教授
  • Apr. 2009 Mar. - 2012, 奈良女子大学大学院人間文化研究科共生自然科学専攻・教授
  • Apr. 2007 Mar. - 2009, 奈良女子大学大学院人間文化研究科共生自然科学専攻・准教授
  • Apr. 2007 Mar. - 2008, 京都大学化学研究所客員准教授
  • Apr. 2003 Mar. - 2007, 奈良女子大学大学院人間文化研究科基盤生活科学講座・助教授
  • Apr. 1999 Mar. - 2003, 奈良女子大学大学院人間文化研究科人間環境基礎講座・助教授
  • Apr. 1997 Mar. - 1999, 奈良女子大学生活環境学部・助教授
  • Oct. 1989 Mar. - 1997, 東京工業大学工学部・助手
  • Oct. 1991 Mar. - 1992, 英国Surrey大学化学科・博士研究員

Education

  • - 1987, Tokyo Institute of Technology, Graduate School, Division of Science and Engineering, 高分子工学
  • - 1985, Tokyo Institute of Technology, Faculty of Engineering, 高分子工学科

Committee Memberships

  • The Japan Society of Home Economics被服材料部会幹事
  • The Society of Fiber Science and Technology, Japan関西支部役員
  • The Society of Polymer Science, JapanNMR研究会 運営委員会 副運営委員長
  • The Society of Polymer Science, Japan高分子学会関西支部常任幹事

Awards

  • 繊維学会賞, The Society of Fiber Science and Technology, Japan, Jun. 2010
  • 高分子研究奨励金(現:高分子研究奨励賞), Hiromichi Kurosu, Society of Polymer Science, Japan, May 1997

Published Papers

  • Metallization of PET textile utilizing supercritical CO2 catalyzation

    Kenichi Tokuoka; Chun Yi Chen; Tso Fu Mark Chang; Wan Ting Chiu; Hiromichi Kurosu; Masato Sone

    © 2020 Elsevier B.V. Metallization of polyethylene terephthalate (PET) textiles was realized by conducting the catalyzation step in supercritical CO2 and using an organometallic compound, palladium bis-hexafluoracetylacetonate (Pd(hfa)2, as source of the palladium catalyst for the later Ni-P deposition step. Electrical resistance of the Ni-P/PET was evaluated before and after adhesion and high temperature incubation tests to reveal durability of the Ni-P/PET. Electrical resistances of the Ni-P/PET prepared at 343 K did not vary much after two cycles of the tape adhesion test when the deposition time was longer than 1.0 h. The Ni-P/PET metallized at 343 K for 2.0 h retained a low electrical resistance at 0.038 Ω after the high temperature incubation test at 414 K. The supercritical CO2 catalyzation was confirmed to be an effective method to metallize PET textile., 15 Feb. 2020, Microelectronic Engineering, 223, doi;scopus;scopus_citedby

    Scientific journal

  • Ni–P and TiO2 codeposition on silk textile via supercritical CO2 promoted electroless plating for flexible and wearable photocatalytic devices

    Wan Ting Chiu; Chun Yi Chen; Tso Fu Mark Chang; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    © 2018 Elsevier Ltd This study reported integration of Ni–P/TiO2 incorporated structure on silk textiles to produce a flexible, highly reliable, and photocatalytic composite material toward applications in functional wearable devices. Supercritical carbon dioxide (Sc–CO2) promoted electroless plating was utilized to codeposit photocatalytic TiO2 and electrically conductive Ni–P metallization layer on silk textile. Silk was chosen as the substrate for its flexibility and stretchability. Ni–P was utilized due to its high corrosion resistance, electrical conductivity, and high wear resistance. TiO2 was selected for its photocatalytic activity and acting as a reinforcement filler to fulfill requirements for applications in wearable devices. Surface morphology, composition, crystal structure, electrical resistance, corrosion resistance, adhesive test, and photocatalytic activity assessments were conducted to evaluate the practicability for wearable photocatalytic devices. With the assistance of sc–CO2, palladium (II) acetylacetonate catalyst was successfully embedded into the silk substrate at around 330 nm in depth. The coatings on the silk were confirmed to be amorphous Ni–P phase and TiO2 anatase phase. Uniform Ni–P/TiO2 composite layer with strong adherence was successfully co–deposited on the silk textile. Ni–P/TiO2 composite layer deposited with 30 g/L of TiO2 (critical concentration) in the electrolyte showed higher corrosion resistance while comparing to those of TiO2–free specimen. The Ni–P/TiO2 composite layer deposited with the critical concentration of TiO2 in the electrolyte performed the highest photocatalytic activity., 20 Jan. 2019, Electrochimica Acta, 294, 68 - 75, doi;scopus;scopus_citedby

    Scientific journal

  • Platinum coating on silk by a supercritical CO2 promoted metallization technique for applications of wearable devices

    Wan Ting Chiu; Chun Yi Chen; Tso Fu Mark Chang; Yuma Tahara; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    © 2018 Elsevier B.V. Highly reliable Pt coating on silk textile was practiced by supercritical carbon dioxide (sc-CO2) promoted electroless plating in this study. Electroless plating is a facile method to integrate polymeric and metallic materials, and sc-CO2 was introduced to the process to enhance the electroless plating characteristics. Firstly, the palladium organometallic complex was inlaid into the silk substrate without damaging the silk structure in the catalyzation step. Secondly, a smooth and compact Pt layer was realized in the metallization step. Mechanisms involved in the sc-CO2-assisted metallization step were focused and discussed in this study. The lowest electrical resistance was found at 50 mΩ in the sample metallized with the optimized conditions. The adhesive test showed robustness of the composite material. Corrosion resistance results revealed the applicability of this silk-Pt composite materials prepared by the sc-CO2-assisted electroless plating in wearable device technology., 25 Sep. 2018, Surface and Coatings Technology, 350, 1028 - 1035, doi;scopus;scopus_citedby

    Scientific journal

  • Fabrication and Photocatalytic Performance of Au/ZnO Layered Structure on Silk Textile for Flexible Device Applications

    Wan-Ting Chiu; Chun-Yi Chen; Tso-Fu Mark Chang; Yuma Tahara; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    This study integrated ZnO/Au layered structure on silk textiles to realize a flexible photocatalytic composite material for wearable devices. Supercritical carbon dioxide promoted electroless plating and cathodic deposition were used to metallize and deposit photocatalytic metal oxides on silk textiles. Silk was used as the substrate for its flexibility and stretchability. Au was selected due to its high biocompatibility, electrical conductivity, and ductility. ZnO was chosen for its photocatalytic activity and biocompatibility to fulfill the application. Surface morphology, composition, crystal structure, electrical resistance and photocatalytic activity assessments were evaluated. With the assistance of supercritical carbon dioxide, smooth, strong adherence and uniform coverage of Au layer was successfully electroless plated on the silk. ZnO was homogeneously deposited on the Au metal layer. The coatings on the silk have been confirmed to be metallic Au phase and ZnO wurtzite phase. The ZnO modified specimen with 0.2 wt. % H2O2 in the electrolyte showed the highest crystallinity and performed 11.5 times enhancement in the photocurrent density when comparing to the H2O2-free one. (C) 2017 Elsevier Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, Nov. 2017, ELECTROCHIMICA ACTA, 253, 39 - 46, doi;web_of_science

    Scientific journal

  • Fundamental Property Assessments of Biocompatible Silk-Pt Composite Prepared by Supercritical Carbon Dioxide Promoted Electroless Plating

    Wan-Ting Chiu; Yuma Tahara; Chun-Yi Chen; Tso-Fu Mark Chang; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    This study reports preparation and characterization of biocompatible, conductive, and flexible silk-Pt composite materials for applications in wearable and medical devices. The distinct Pt and silk materials were integrated via supercritical carbon dioxide (sc-CO2) promoted electroless plating. Sc-CO2 was introduced into the catalyzation step, which is a critical step in electroless plating, to overcome the common difficulty of inlaying the catalyst into the textile substrate. High surface coverage and thick Pt layer were constructed as the metallization time extended. Metal ions released in a simulated body fluid in an immersion test were negligible when compared to the daily metal input and output of the human body. The composites showed high corrosion resistances in both 3.5 wt % NaCl and simulated body fluid solutions. The electrical conductivity and corrosion resistance persisted after the adhesion tests. The assessments revealed the applicability of this silk-Pt material to wearable and medical devices., AMER CHEMICAL SOC, Aug. 2017, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 56 (31), 8864 - 8871, doi;web_of_science

    Scientific journal

  • Silk-Pt composite integration by supercritical carbon dioxide assisted electroless plating for medical devices application

    Wan-Ting Chiu; Yuma Tahara; Chun-Yi Chen; Tso-Fu Mark Chang; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    This study successfully integrated flexible silk textiles and highly conductive platinum together by a supercritical CO2-assisted electroless plating process to achieve the materials for wearable medical devices. Pt and silk textiles were chosen for the composite material due to the request of high biocompatibility in the applications. Supercritical CO2 was introduced to the catalyzation step in the electroless plating process to promote the catalyst deposition. Surface morphology, composition, crystal structure, electrical resistance and biocompatibility assessments were evaluated. Coverage of the Pt layer increased as a function of the plating time. The thickness reached 0.91 pm when 200 min of the plating time was used. The lowest resistance at 86 ma was obtained when the plating time was extended to 160 min. The Pt ion releasing rate in the r-type simulated body fluid was negligible when comparing with the daily input and output of Pt in human body. (C) 2016 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, May 2017, MICROELECTRONIC ENGINEERING, 175, 34 - 37, doi;web_of_science

    Scientific journal

  • A Supercritical CO2 Promoted Electroless Ni-P Plating on Silk and Their Fundamental Characteristics Investigations

    Wan-Ting Chiu; Yuma Tahara; Chun-Yi Chen; Tso-Fu Mark Chang; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    This study demonstrated a promising method to integrate flexible silk textiles and conductive Ni-P metal coatings for the increasing interest in wearable devices. Electroless plating with supercritical carbon dioxide (sc-CO2) was utilized to combine the two distinct materials together conformally. Ni-P was chosen for its electrical conductivity and high corrosion resistance while silk was chosen as the substrate for its flexibility. Sc-CO2 was used as a promoter in the catalyzation to enhance the compatibility between the Ni-P with the silk. This technique allows simplification of the electroless plating by excluding the pretreatments while the substrate remains undamaged after the catalyzation step. In addition, the sc-CO2 leads to an environmental friendly process by cutting down the usage of corrosive chemicals in the catalyzation step. This study therefore demonstrates a series of palladium (II) acetylacetonate catalyzation followed by Ni-P deposition on the silk. The lowest electrical resistance at 1.02 Omega was achieved at 4 min of the Ni-P plating time. Corrosion resistance of the Ni-P/silk in a solution simulating the human sweat was evaluated. Reliability of the Ni-P/silk composite material was revealed by comparing the electrical resistances and corrosion resistances before and after an adhesive test. (C) 2017 The Electrochemical Society. All rights reserved., ELECTROCHEMICAL SOC INC, 2017, JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 164 (7), D406 - D411, doi;web_of_science

    Scientific journal

  • Application of supercritical carbon dioxide in catalyzation and Ni-P electroless plating of nylon 6,6 textile

    Mitsuo Sano; Yuma Tahara; Chun-Yi Chen; Tso-Fu Mark Chang; Tomoko Hashimoto; Hiromichi Kurosu; Tatsuo Sato; Masato Sone

    In this study, an electroless deposition method including catalyzation in supercritical carbon dioxide (sc-CO2) and plating in sc-CO2 emulsified electrolyte was applied in metallization of Nylon 6,6 textile. In order to demonstrate the effects of the sc-CO2, the catalyzation was conducted either by the conventional method or the supercritical CO2 catalyzation (SCC) method with bis (2,4-pentandionato)-palladium. After the catalyzation process, either the conventional electroless plating or the electroless plating with supercritical CO2 emulsified electrolyte (ELP-SCE) was performed. Surface of the Ni-P coatings on the Nylon 6,6 was observed by an optical microscope and a scanning electron microscope. The Ni-P coating by the conventional catalyzation and the conventional electroless plating showed some cracks, nodules and rough structure. The Ni-P coating by the SCC and the conventional electroless plating showed smooth Ni-P coating on the surface of each fibers and had some peeled-off parts. On the other hand, uniform Ni-P coating on the surface of each fibers was obtained by the SCC and the ELP-SCE. These results demonstrated that the SCC is effective to impregnate Pd catalysts into the fibers, and the ELP-SCE can inhibit the nodule growth of the Ni-P. Thus, the proposed method can metallize the surface of each Nylon 6,6 fibers and has potential to give some functions on textiles. (C) 2016 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Sep. 2016, SURFACE & COATINGS TECHNOLOGY, 302, 336 - 343, doi;web_of_science

    Scientific journal

  • Metallization of textile by Pt catalyzation in supercritical carbon dioxide and Pt electroless plating for applications in wearable devise

    Mitsuo Sano; Yuma Tahara; Tso-Fu Mark Chang; Chun-Yi Chen; Tomoko Hashimoto; Hiromichi Kurosu; Masato Sone

    In this study, an electroless plating method involved Pt catalyzation in supercritical carbon dioxide (sc-CO2) and conventional Pt electroless plating was used for the metallization of polyamide 6,6 (PA66) textiles. The catalyzation was conducted either by conventional method at atmospheric pressure or in sc-CO2 with bis (2,4-pentandionato)-platinum. After the catalyzation process, the conventional Pt electroless plating method was performed for the Pt catalyzed PA66 textiles. Surface of the Pt coated PA66 was observed by an optical microscope and a scanning electron microscope. The Pt coating by the conventional catalyzation had a rough surface, and the surface did not show the textile outline because of the dissolution of the textile in the conventional catalyzation solution. The textile metallized by the sc-CO2 catalyzation showed a metallic bright coating, and the Pt coating was observed on the surface of each fiber. These results indicate that the sc-CO2 catalyzation is a promising method to catalyze the PA66 textile. (C) 2016 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Mar. 2016, MICROELECTRONIC ENGINEERING, 153, 92 - 95, doi;web_of_science

    Scientific journal

  • Solid-state C-13 NMR study of banana liquid crystals-3: Alkyl-tail-group packing environments of an acute-angle bent-core molecule in the hexagonal columnar and cubic phases

    Kurosu, Hiromichi; Endo, Yumi; Kimura, Saori; Hashimoto, Tomoko; Harada, Motoi; Lee, Eun-Woo; Sone, Masato; Watanabe, Junji; Kang, Sungmin

    Solid-state C-13 nuclear magnetic resonance (NMR) measurements were performed on the hexagonal columnar and cubic phases of an acute-angle banana-shaped molecule, N(1,7)-S30. In the hexagonal columnar phase, three peaks appear at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that the two alkyl tails have different packing structures, and one of the tails has two different conformations within a single molecule. Combined cross-polarization/magic-angle spinning and pulse saturation transfer/magic-angle spinning measurements show that one of the alkyl chains is located inside and the other is located outside the columnar structure. In the cubic phase, pulse saturation transfer/magic-angle spinning measurement shows that only one peak appears at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that both of the alkyl chains are located outside the cubic structure. (C) 2015 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Feb. 2016, JOURNAL OF MOLECULAR STRUCTURE, 1105, 34 - 40, doi;web_of_science

    Scientific journal

  • Synthetic macromolecules

    Hiromichi Kurosu; Takeshi Yamanobe

    In this chapter, the papers devoted to NMR application to study synthetic polymers over a period from June 2013 through May 2014 have been reviewed. It includes analysis of primary structure of polymers such as tacticity, regioregularity, end group, sequence distribution (Section 2), application of imaging, diffusion and solid-state NMR techniques to characterize the synthetic macromolecules (Sections 3 and 4). Finally in Section 5, papers devoted to dynamics of the synthetic macromolecules have been surveyed., Royal Society of Chemistry, 2015, Nuclear Magnetic Resonance, 44, 431 - 455, doi

    Scientific journal

  • Synthetic macromolecules

    Hiromichi Kurosu; Takeshi Yamanobe

    In this chapter, the papers devoted to NMR application to study synthetic polymers over a period from June 2012 through May 2013 have been reviewed. It includes analysis of primary structure of polymers such as tacticity, regioregularity, end group, sequence distribution (Section 2), application of imaging, diffusion and solid-state NMR techniques to characterize the synthetic macromolecules (Sections 3 and 4). Finally in Section 5, papers devoted to dynamics of the synthetic macromolecules have been surveyed., Royal Society of Chemistry, 2014, Nuclear Magnetic Resonance, 43, 423 - 456, doi

    Scientific journal

  • Sites of protonation and copper(II)-complexation in protic ionic liquids comprised of N-hexylethylenediaminium cation

    Mayu Watanabe; Shinobu Takemura; Sayaka Kawakami; Emi Syouno; Hiromichi Kurosu; Masafumi Harada; Masayasu Iida

    Protonation sites of a chelating mono-protic ionic liquid (PIL) comprising N-hexylethylenediaminium (= HHexen(+)) depending on the counter anion were studied by N-15 and C-13 NMR spectroscopy and DFT calculation. In the case of the bis(trifluoromethanesulfonyl) amide (=TFSA(-)) PIL, the protonation occurred almost at the secondary amine, whereas the protonation occurred preferentially at the primary amine in the trifluoroacetate (= TFA(-)) PIL The formation of a chelating copper(II) complex with the cationic unit of the PIL despite the electrostatic repulsion was revealed using the paramagnetic broadenings of the C-13 NMR spectra of the PILs. (C) 2013 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Jul. 2013, JOURNAL OF MOLECULAR LIQUIDS, 183, 50 - 58, doi;web_of_science

    Scientific journal

  • Solid-state C-13 NMR study of banana liquid crystals-2: Alkyl tail-group packing environments in the hexagonal columnar phase

    Kurosu, Hiromichi; Endo, Yumi; Kimura, Saori; Hashimoto, Tomoko; Harada, Motoi; Lee, Eun-Woo; Sone, Masato; Watanabe, Junji; Kang, Sungmin

    Solid-state C-13 nuclear magnetic resonance (NMR) measurements were performed in order to obtain the packing structure of alkyl tail in the hexagonal columnar phase of the banana-shaped N(1,7)-S16 molecule. In this phase, NMR chemical shifts assigned to the internal methylene carbons at an amorphous state appear as two peaks, indicating that the two alkyl tails are placed under two different chemical environments. From combined cross-polarization/magic-angle spinning and pulse saturation transfer/magical-angle spinning measurements, two alkyl tails were found to have the different mobility. Such two different environments are not unusual in conventional mesophases, but in the hexagonal columnar phase formed by cylindrical columns composed of enclosed smectic layers; one of the alkyl tails is located inside and the other is located outside the columnar structure. (C) 2013 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, May 2013, JOURNAL OF MOLECULAR STRUCTURE, 1040, 117 - 121, doi;web_of_science

    Scientific journal

  • NMR Spectroscopy in Polymer Science

    I. Ando; M. Kobayashi; M. Kanekiyo; S. Kuroki; S. Ando; S. Matsukawa; H. Kurosu; H. Yasunaga; S. Amiya

    Elsevier Inc., 02 Dec. 2012, Experimental Methods in Polymer Science: Modern Methods in Polymer Research and Technology, 261 - 493, doi

    In book

  • A specialist periodical report on nuclear magnetic resonance (2011/8) synthetic macromolecules

    Hiromichi Kurosu; Takeshi Yamanobe

    2012, Nuclear Magnetic Resonance, 41, 386 - 428, doi

    Scientific journal

  • Solid-state C-13 NMR study of banana liquid crystals - 1: Two different alkyl tail-group packing environments in the B7 phase

    Kurosu, Hiromichi; Nakanishi, Saki; Kimura, Saori; Kang, Sungmin; Li, Xiaodong; Sone, Masato; Watanabe, Junji

    Solid-state C-13 nuclear magnetic resonance (NMR) measurements were performed for the B7 phase of the banana-shaped molecule P-8-O-PIMB(NO2). In this phase, NMR chemical shifts assigned to five methylene carbons on the alkyl tail appear as at least seven peaks, indicating that the two alkyl tails within a single molecule have different packing structures. Combined CP/MAS and PST/MAS measurements show that one of the alkyl tails has dense packing with low molecular mobility and the other has loose packing with high molecular mobility. Thus, it can be concluded that both the polar bent and molecular axes are tilted toward the layer in the B7 phase of P-8-O-PIMB(NO2), exhibiting molecular leaning. (C) 2011 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Jan. 2012, JOURNAL OF MOLECULAR STRUCTURE, 1008, 49 - 53, doi;web_of_science

    Scientific journal

  • Crystalline structure of polyethylene containing vinylene units in the main chain

    Naofumi Naga; Rika Arai; Genzo Kikuchi; Akinori Toyota; Keiichi Noguchi; Masato Sone; Fukiko Shirae; Tomoka Gotoh; Hiromichi Kurosu

    Polyethylene containing trans- or cis-vinylene units in the main chain has been synthesized by means of partial hydrogenation of trans- or cis-polypentenamer (TP or CP), and trans-polyoctenamer (TO). Crystalline structure of the polymers has been investigated with wide-angle X-ray diffraction, FT-IR analyses, solid-state NMR measurements and quantum chemical calculations of the NMR chemical shifts. These results clear that the partially hydrogenated TP or CP samples having an average number of methylene units of 6.9-8.4 per vinylene unit forms not only orthorhombic crystal but hexagonal-like crystal. (C) 2011 Elsevier Ltd. All rights reserved., ELSEVIER SCI LTD, Sep. 2011, POLYMER, 52 (21), 4857 - 4866, doi;web_of_science

    Scientific journal

  • Precise side-chain conformation analysis of l-phenylalanine in α-helical polypeptide by quantum-chemical calculation and 13C CP-MAS NMR measurement

    Subaru Niimura; Junya Suzuki; Hiromichi Kurosu; Takeshi Yamanobe; Akira Shoji

    To clarify the positive role of side-chain conformation in the stability of protein secondary structure (main-chain conformation), we successfully calculated the optimization structure of a well-defined α-helical octadecapeptide composed of l-alanine (Ala) and l-phenylalanine (Phe) residues, H-(Ala)8-Phe-(Ala)9-OH, based on the molecular orbital calculation with density functional theory (DFT/B3LYP/6-31G(d)). From the total energy and the precise secondary structural parameters such as main-chain dihedral angles and hydrogen-bond parameters of the optimized structure, we confirmed that the conformational stability of an α-helix is affected dominantly by the side-chain conformation (χ1) of the Phe residue in this system: model A (T form: around 180° of χ1) is most stable in α-helix and model B (G+ form: around -60° of χ1) is next stable, but model C (G- form: around 60° of χ1) is less stable. In addition, we demonstrate that the stable conformation of poly(l-phenylalanine) is an α-helix with the side-chain T form, by comparison of the carbonyl 13C chemical shift measured by 13C CP-MAS NMR and the calculated one. © 2010 Elsevier B.V. All rights reserved., 22 Apr. 2010, Journal of Molecular Structure, 969 (1-3), 40 - 47, doi

    Scientific journal

  • Precise Structural Analysis of Polypeptides by Quantum Chemical Calculation

    Hiroyuki Souma; Hiromichi Kurosu; Akira Shoji

    We computed the optimized structure of alpha(R)-helical polypeptides, H-(Ala)(18)-OH and H-(Ala-Gly)(9)-OH, based on the molecular orbital calculation with density functional theory (DFT/6-31G(d)), and then the H-1, C-13, N-15 and O-17 nuclear shieldings of those optimized structures based on the GIAO-CHF method with B3LYP/6-311G(d, p). In conclusion, we demonstrated that the precise quantum chemical calculation is extremely useful for the secondary and tertiary structural analysis of some proteins and polypeptides. We demonstrated concretely that the precise secondary structural parameters (phi = -62 degrees, psi = -43 degrees), hydrogen bond parameters and the calculated isotropic C-13 and N-15 chemical shifts of the main-chain for the optimized structures were greatly in good agreement with the data by X-ray (or neutron) diffraction analysis and the chemical shifts by high-resolution solid-state NMR. Furthermore, we successfully demonstrated that the L-proline residue is certainly included in the alpha(R)-helix conformation by the quantum chemical calculation and by the C-13 and N-15 NMR chemical shifts., SOC POLYMER SCIENCE JAPAN, Jan. 2010, KOBUNSHI RONBUNSHU, 67 (1), 10 - 27, web_of_science

    Scientific journal

  • Molecular dynamics and orientation of stretched rubber by solid-state C-13 NMR

    Hideaki Kimura; Hidehiko Dohi; Marina Kotani; Takanobu Matsunaga; Kazuo Yamauchi; Hironori Kaji; Hiromichi Kurosu; Tetsuo Asakura

    The molecular dynamics and orientation of vulcanized natural rubber (NR) stretched at a low extension ratio (alpha=stretched length/original length) were studied by carbon-13 direct polarization-magic angle spinning nuclear magnetic resonance (C-13 DP-MAS NMR), C-13 cross-polarization (CP)-MAS NMR, C-13 DIP NMR without MAS, C-13 CP NMR without MAS and density functional theory (DFT) calculations. Gradual peak broadening was observed in the C-13 DP-MAS NMR spectra of stretched NR with an increasing extension ratio, indicating that the molecular mobility of NR chains is restricted by stretching. The static C-13 NMR spectra of uniaxially stretched NR (alpha=2) changed slightly depending on the angle, theta, between the stretching direction and the applied magnetic field, although the spectra of unstretched NR did not change even if theta was changed. Thus, it is noted that NR chains oriented slightly as a time average by stretching even at a low extension ratio, alpha=2, although there still exists rapid rotation around the oriented NR chain. Motionally narrowed anisotropies in the C-13 spectra of stretched NR and the directions of chemical shift anisotropy principal axes determined by DFT calculations suggest that isoprene units of oriented rubber chains in stretched NR rotate rapidly around the axis that almost aligned with the C=C bond direction of polyisoprene. Polymer Journal (2010) 42, 25-30; doi:10.1038/pj.2009.307, NATURE PUBLISHING GROUP, Jan. 2010, POLYMER JOURNAL, 42 (1), 25 - 30, doi;web_of_science

    Scientific journal

  • Structure and dynamics of poly(ethylene-co-1,5-hexadiene) as studied by solid state C-13 NMR and quantum chemical calculations

    Kurosu, Hiromichi; Yamamoto, Yuuri; Fujikawa, Aki; Kawabata, Emika; Sone, Masato; Naga, Naofumi

    Poly(ethylene-co-1,5-hexadiene) with 1,5-hexadiene (HD) contents of 1.8, 8.1, 9.7 and 20.3% was prepared by copolymerization of ethylene and HD involving intermolecular cyclization. Higher-order structures and dynamics of these samples were Studied by solid state NMR and quantum chemistry. The C-13 solid state NMR spectra and C-13 spin-lattice relaxation time (T-1) of the samples were measured. The observed C-13 CP/MAS and PST/MAS NMR spectra for all samples were decomposed into six peaks. The cyclopentane units incorporated in the main chain of polyethylene affected not only the crystalline structure but also the noncrystalline structure. This causes a trans-rich conformation in the noncrystalline region. Even in the melt-quenched samples, incorporation of the cyclopentane structure into the polyethylene chain suppresses the increase in the gauche structure in the noncrystalline region. Based on the C-13 chemical shift of the methylene carbon. the low cyclopentane content sample assumes an orthorhombic crystal structure, and the high cyclopentane content samples assume a hexagonal-type chain packing. C-13 spin-lattice relaxation times show that the crystalline region of the low cyclopentane content sample has two regions with different mobility, although the high cyclopentane content samples have only one region with a high mobility for each peak. Furthermore, quantum chemical calculations for the C-13 NMR shieldings were carried out for precise assignment of the peaks. (C) 2008 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Mar. 2009, JOURNAL OF MOLECULAR STRUCTURE, 921 (1-3), 208 - 214, doi;web_of_science

    Scientific journal

  • Theoretical investigations of C-13 chemical shifts in glucose, cellobiose, and native cellulose by quantum chemistry calculations

    Shinji Suzuki; Fumitaka Horii; Hiromichi Kurosu

    The effects of the conformation and hydrogen bonding on C-13 isotropic chemical shifts have theoretically been investigated for beta-D-glucose, D-cellobiose, and the cellobiose units of native cellulose by quantum chemistry calculations based on the DFT method. The linear relationship between the chemical shift of the C6 carbon and the torsion angle around the C6-O6 bond in the CH2OH side group, which was previously obtained in experiments, is Successfully reproduced for beta-D-glucose by the theoretical calculations. A similar linear relationship is also found to hold for the C4 carbon, supporting the previous finding in experiments. Moreover, the C5 chemical shift also depends on the conformation of the side group, but the conformation of the O6H hydrogen atom at the gamma position may mainly contribute to the dependence for the C5 carbon through the possible formation of intramolecular hydrogen bonding. The gamma(H)-gauche effect produced by the OH hydrogen atom (gamma-H) at the gamma position is found, for the first time, to induce 3-5 ppm downfield shift for the carbon in question, and this effect reduces by 2-3 ppm when the intramolecular hydrogen bonding associated with gamma-H is formed. Similar calculations for D-cellobiose and the cellobiose units in native cellulose reveal appreciable dependences of the C1 and C4 chemical shifts on the torsion angles phi and psi around the (1 -> 4)-beta-glycosidic linkage. In contrast, no significant effects of different intramolecular and intermolecular hydrogen bondings forming between neighboring glucose residues are recognized on the chemical shifts of the respective carbons associated with these hydrogen bondings. (C) 2009 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Mar. 2009, JOURNAL OF MOLECULAR STRUCTURE, 921 (1-3), 219 - 226, doi;web_of_science

    Scientific journal

  • Theoretical investigations of the gamma-gauche effect on the C-13 chemical shifts produced by oxygen atoms at the gamma position by quantum chemistry calculations

    Shinji Suzuki; Fumitaka Horii; Hiromichi Kurosu

    The gamma-gauche effect on C-13 chemical shifts that is produced by the O atoms located at the gamma positions has been evaluated by quantum chemistry calculations based on the GAIO-CHF procedure. The gamma-gauche effects produced by the O and Cl atoms in n-propanol and n-propyl chloride are found to be, respectively, +1.4 and -0.7 ppm, whereas that due to the C atom in n-butane is -3.0 ppm in good agreement of the values previously calculated. The apparent cause of such a difference in the gamma-gauche effect is mainly relatively higher shielding of the CH3 carbon in the trans conformation for the n-propanol and n-propyl chloride. Extending the n-propanol chain at both ends causes no significant change in the gamma-gauche effect produced by the O atom. In 2-butanol and 2-methyl-2-butanol as examples of secondarily and tertiarily Substituted compounds, the gamma-gauche effects produced by the gamma-OH groups are estimated to be -7 to -9 ppm. In addition, the gamma-gauche effect due to the C atom is found to increase in n-butane, secondary, and tertiary butanols in this order. The gamma-gauche effect produced by the O atom in hydroxyethylcyclohexane is as negligibly small as -0.7 ppm, whereas that produced by the C atom in ethylcyclohexane is about -5 ppm. These results suggest that the gamma-gauche effect, including downfield shift, produced by the O atom in a compound greatly depends on its chemical structure, whereas upfield shifts of -3 to -7 ppm are induced in all examined Compounds as the gamma-gauche effect due to the C atom. (C) 2008 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Feb. 2009, JOURNAL OF MOLECULAR STRUCTURE, 919 (1-3), 290 - 294, doi;web_of_science

    Scientific journal

  • Precise structural analysis of alpha-helical copolypeptide H-(Ala-Gly)(9)-OH by quantum chemical calculation and high-resolution solid-state NMR measurement

    Hiroyuki Souma; Yoko Shigehisa; Hiromichi Kurosu; Akira Shoji

    We computed the optimized structure of sequential 18-mer copolypeptide H-(Ala-Gly)(9)-OH (C45H74N18O19) adopting an right-handed alpha-helix (alpha(R)-helix) conformation with the basis set of DFT/6-31G(d), and then calculated the nuclear shieldings of the optimized structure with the basis set of DFT/6-311G(d,p). As a result, we confirmed highly accurate conformational parameters characteristic to the alpha(R)-helical H-(Ala-Gly)(9)-OH, which were identical with those of the individual Ala and Gly residues. Most of these parameters were fundamentally the same as those obtained for the optimized CER-helical H(Ala)(18)-OH. Furthermore, it was found that the calculated isotropic C-13 and N-15 chemical shifts were dependent on the nature of individual amino acid residues, which were greatly in good agreement with those of alpha(R)-helical model copolypeptides consisting of L-alanine and glycine residues measured by high-resolution solid-state NMR., ELSEVIER SCIENCE BV, Nov. 2008, JOURNAL OF MOLECULAR STRUCTURE, 891 (1-3), 58 - 63, doi;web_of_science

    Scientific journal

  • Precise structural analysis of alpha-helical poly(L-alanine) by quantum chemical calculation

    Akira Shoji; Hiroyuki Souma; Takuo Ozaki; Hiromichi Kurosu; Isao Ando; Stefan Berger

    It is extremely important to elucidate the formation mechanism of the secondary structure in polypeptides and proteins. This enables the stability of the three-dimensional structure of proteins to be predicted theoretically. For this purpose, the development of a precise structural calculation is indispensable. We computed the optimized structure of a poly(L-alanine) (PLA) molecule, H-Ala(18)-OH (C54H92N18O19), adopting a right-handed alpha-heliX (OCR-helix) conformation based on the molecular orbital calculation with density functional theory (DFT/6-31G(d)). As a result, we confirmed highly accurate conformational parameters characteristic to the "most acceptable alpha(R)-helix PLA" as follows; intrinsic dihedral angles (phi,psi,omega) = (-62 degrees, -43 degrees, 178 degrees); hydrogen-bond distances R-O center dot center dot center dot H = 0.205 nm and R-O center dot center dot center dot N = 0.303 nm; hydrogen-bond angles angle C=O center dot center dot center dot H = 149 degrees and angle N-H center dot center dot center dot O = 160 degrees. Furthermore, we calculated the H-1, C-13, N-15 and O-17 nuclear shieldings of the optimized OCR-helical H-Ala(18)-OH with the base set of DFT/6-311G(d,p), and demonstrated that the calculated isotropic C-13 and H-1 chemical shifts were identical with those measured by high-resolution solid-state NMR. (C) 2008 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Oct. 2008, JOURNAL OF MOLECULAR STRUCTURE, 889 (1-3), 104 - 111, doi;web_of_science

    Scientific journal

  • Formation of molecular glasses and the aggregation in solutions for lanthanum(III), calcium(II), and yttrium(III) complexes of octanoyl-DL-alaninate

    Gerile Naren; Rie Masuda; Masayasu Iida; Masafumi Harada; Hiromichi Kurosu; Toshiharu Suzuki; Takayoshi Kimura

    Octanoylalaninato-metal (metal = calcium(II), yttrium(III), lanthanum(III), and zinc(II)) complexes were prepared and the first three metal complexes were found to readily form transparent and stable molecular glasses from methanol and chloroform solutions. The process of glass formation from solution was studied in detail. The effect of the central metal ions on the formation of glassy states was remarkable: the lanthanum and calcium complexes assumed glassy or crystalline states depending on the isolation method and the yttrium complex had a large tendency to assume an amorphous state, whereas the zinc complex did not assume a pure and stable glassy-state. The glass transition temperatures were 50 degrees C for the yttrium complex and 70-75 degrees C for the lanthanum and calcium complexes when these complexes are monohydrates prepared by a solvent-cast method, whereas they increase by 10-30 degrees for the hemihydrates which were obtained by an annealing treatment at 110 degrees C. The coordinated water was eliminated from the solid above the glass transition temperature. The glassy state was regarded as a result of the self-aggregation of the metal complex in solution by an entanglement of the methylene chains with one another. SAXS showed the presence of two disordered bilayer structures with 2.2 nm and 4.5 nm periods in the glassy states. The structures of the molecular assemblies in the solid states and solutions were compared by SAXS and NMR studies. EXAFS studies confirmed the coordination numbers of oxygen atoms around the yttrium and lanthanum atoms in the glassy states for the yttrium and lanthanum complexes to be about 7., ROYAL SOC CHEMISTRY, Apr. 2008, DALTON TRANSACTIONS, (13), 1698 - 1709, doi;web_of_science

    Scientific journal

  • High field O-17 solid-state NMR study of alanine tripeptides

    Kazuo Yamauchi; Michi Okonogi; Hiromichi Kurosu; Masataka Tansho; Tadashi Shimizu; Terry Gullion; Tetsuo Asakura

    O-17-chemical shifts of Ala-Ala-Ala, with parallel and anti-parallel beta-sheet structures, are observed using a 930-MHz high-resolution solid-state NMR spectrometer. Ala-Ala-Ala serves as a model sheet-forming peptide because it can be easily prepared as either a parallel or an anti-parallel beta-sheet structure. Spectral differences between the two samples are observed which arise from molecular packing differences between the two sheet structures. DFT chemical shift calculations are performed for the two samples, and the calculated spectra are in good agreement with the experimental spectra. The DFT calculations provide insight into the nature of the chemical shift differences observed between the two sheet structures. (c) 2007 Elsevier Inc. All rights reserved., ACADEMIC PRESS INC ELSEVIER SCIENCE, Feb. 2008, JOURNAL OF MAGNETIC RESONANCE, 190 (2), 327 - 332, doi;web_of_science

    Scientific journal

  • High-field 1H MAS and15N CP-MAS NMR studies of alanine tripeptides and oligomers: Distinction of antiparallel and parallel β-sheet structures and two crystallographically independent molecules

    Yu Suzuki; Michi Okonogi; Kazuo Yamauchi; Hiromichi Kurosu; Masataka Tansho; Tadashi Shimizu; Hazime Saitô; Tetsuo Asakura

    β-Strand peptides are known to assemble into either antiparallel (AP) or parallel (P) β-sheet forms which are very important motifs for protein folding and fibril formations occurring in silk fibroin or amyloid proteins. Well-resolved 1H NMR signals including NH protons were observed for alanine tripeptides (Ala)3 with the AP and P structures as well as (Ala)n (n = 4-6) by high-field/fast magic-angle spinning NMR. Amide NH and amino NH3+ 1H signals of (Ala) 3 with the P structure were well resonated at 7.5 and 8.9 ppm, respectively, whereas they were not resolved for the AP structure. Notably, NH 1H signals of (Ala)3 and (Ala)4 taking the P structure are resonated at higher field than those of the AP structure by 1.0 and 1.1 ppm, respectively. Further, NH 15N signals of (Ala) 3 with the AP structure were resonated at lower field by 2 to 5 ppm than those of (Ala)3 with the P structure. These relative 1H and 15N hydrogen bond shifts of the P structure with respect to those of the AP structure are consistent with the relative hydrogen bond lengths of the interstrand N-H⋯O=C bonds. Distinction between the two crystallographically independent chains present in the AP and P structures was feasible by 15N chemical shifts but not by 1H chemical shifts because of insufficient spectral resolution in the latter. Calculated 1H and 15N shielding constants by density functional theory are generally consistent with the experimental data, although some discrepancies remain depending upon the models used. © 2007 American Chemical Society., American Chemical Society, 02 Aug. 2007, Journal of Physical Chemistry B, 111 (30), 9172 - 9178, doi;pubmed

    Scientific journal

  • Structure and mechanical properties of chitosan/poly(vinyl alcohol) blend films

    Yumiko Nakano; Yuezhen Bin; Mami Bando; Teruo Nakashima; Tsumuko Okuno; Hiromichi Kurosu; Masaru Matsuo

    The origins of the thermal and mechanical properties of chitosan and poly(vinyl alcohol) (PVA) with inter- and intra-hydrogen bonds were investigated systematically by using X-ray, DSC, positron annihilation and viscoelastic measurements. Based on their individual properties, the characteristics of the blend films were estimated in relation to their morphology and mechanical properties as a function of chitosan content. The characteristics of the blend films were also analyzed in terms of the deviation from a simple additive rule of chitosan and PVA content. These results suggested that the miscibility of chitosan and PVA could be ensured by entanglement of the amorphous chain segments of chitosan and PVA. Further detailed analysis revealed that the chitosan content on the film surface is higher than that of the admixture content of chitosan after elongation, although the chitosan and PVA chains were crystallized independently. The elongation could be achieved for the blend films whose PVA content was higher than 50% and the drawn blend films were transparent. Thus, it may be expected that sufficiently entangled meshes formed between chitosan and PVA amorphous chains within the film, the PVA content being higher than 50%, were maintained under the elongation process., WILEY-V C H VERLAG GMBH, 2007, MACROMOLECULAR SYMPOSIA, 258, 63 - 81, web_of_science

    International conference proceedings

  • Higher-order structure of poly(ethylene-co-1,5-hexadien) as studied by solid state NMR

    Yuuri Yamamoto; Aki Fujikawa; Masato Sone; Shigemitsu Murase; Naofumi Naga; Hiromichi Kurosu

    Poly(ethylene-co-1,5-hexadien) were prepared by copolymerization of ethylene and 1,5-hexadien(HD) and higher-order structure was studied by solid state NMR. The amorphous structure of the polymer is drastically changed as compared with that of polyethylene even for the sample of the smallest content of HD., 2006, Polymer Preprints, Japan, 55 (1), 733, scopus;scopus_citedby

    International conference proceedings

  • Structural characterization of poly(diethylsiloxane) in the crystalline, liquid crystalline and isotropic phases by solid-state O-17 NMR spectroscopy and ab initio MO calculation

    H Kimura; S Kanesaka; S Kuroki; Ando, I; A Asano; H Kurosu

    The structure of poly(diethylsiloxane) (PDES) has been characterized using solid-state NMR of O-17. The sample studied had a weight-average molecular weight of 2.45 x 10(5). The sample was prepared by utilizing the cationic ring-opening polymerization of O-17-enriched hexacyclotrisiloxane. Solid-state NMR of O-17-enriched PDES was measured on the low-temperature beta(1) phase, the high-temperature beta(2) phase, the two-phase system consisting of the liquid crystal and isotropic liquid phase and the isotropic phase. From these data, the molecular structure and dynamics of PDES in the various phases were characterized via the chemical shifts of O-17, and electric field gradient parameters were determined from NMR and ab initio molecular orbital (MO) calculations. In addition to the solid-state NMR of H-1, C-13 and Si-29 previously reported on these samples, knowledge of the dynamic behavior of PDES as inferred from the NMR of O-17 in the present study was enhanced significantly. Further, the potential of combining the experimental NMR of O-17 with ab initio MO calculations to characterize the dynamics of polymers containing oxygen is demonstrated. Copyright (C) 2004 John Wiley Sons, Ltd., JOHN WILEY & SONS LTD, Mar. 2005, MAGNETIC RESONANCE IN CHEMISTRY, 43 (3), 209 - 216, doi;web_of_science

    Scientific journal

  • Solid-state C-13 NMR study of chiral twisted conformation attributable to chirality in smectic phases of achiral banana-shaped molecules

    H Kurosu; M Kawasaki; M Hirose; M Yamada; SM Kang; M Sone; H Takezoe; J Watanabe

    Solid-state C-13 NMR measurements were made for the B2 and B4 phases of the achiral banana-shaped molecule, P-14-O-PIMB, which exhibits a direct transformation from the 132 phase to the B4 phase. In both phases, an NMR resonance signal assigned to carbonyl carbons of the ester linkages appears as doublet peaks, showing that the two carbonyl carbons are circumstanced in different electronic environments on the NMR time scale. The chemical shifts of the two peaks are 165.6 and 163.9 ppm in the B2 phase, and these values are not changed in the transformation to the low-temperature B4 phase. To explain this distinct splitting of the carbonyl carbon signal, we take three assumptions into account: (1) the molecules are accommodated in the unique phase, but the conformational exchange between two states takes place slowly; (2) the two side wings of each molecule experience fast interconformational jumps, but their "average conformer" is different, thus giving two different peaks in the spectra; and (3) the individual molecule claims the twisted conformation, where the two carbonyl carbons of the ester moieties are twisted away from each other by rotating out of the molecular core plane with different dihedral angles. From the present 13 C NMR results, the first and second possibilities are ruled out, and it is concluded that the banana-shaped molecules assume the twisted conformation, which is attributable to the origin of the chirality of the 132 and B4 phases in the achiral banana-shaped molecular system., AMER CHEMICAL SOC, May 2004, JOURNAL OF PHYSICAL CHEMISTRY A, 108 (21), 4674 - 4678, doi;web_of_science

    Scientific journal

  • Ultradrawing of blend films of ethylene-dimethyl-aminoethyl methacrylate copolymer and ultra-high molecular weight polyethylene prepared by gelation/crystallization from solutions

    M Azuma; L Ma; CQ He; T Suzuki; Y Bin; H Kurosu; M Matsuo

    Copolymer ethylene-dimethyl-aminoethyl methacrylate (EDAM) with 3.9% DAM side groups and ultra-high molecular weight polyethylene (UHMWPE) were blended in decalin solvent. The hot homogenized solution was poured into an aluminum tray to form gels and the decalin was allowed to evaporate from the resultant gels under ambient condition. Surprisingly, the resultant dry blend films could be elongated to more than 200-fold (lambda = 200) even for the blend film with 90% EDAM content (9/1 composition), although the maximum draw ratio of EDAM homopolymer films was 1.6-fold (lambda = 1.6). The mechanism of the great drawability was dependent upon the content of EDAM. The drawability for the 9/1 composite films was attributed to large crystal lamellae of UHMWPE ensuring crystal transition from a folded to a fibrous type. Accordingly, EDAM chains were independent of ultradrawing of UHMWPE and kept a random orientation under ultra-drawing process. The storage (Young's) modulus was 10 GPa at 20degreesC. In contrast, EDAM chains within the 1/1 composite films were oriented drastically together with UHMWPE crystallites. The modulus of the 1/1 composition at 20degreesC reached 68 GPa, which was higher than the value (40 GPa) of polypropylene films with lambda = 100. Such considerable difference of modulus due to EDAM content was analyzed in relation to the gelation/crystallization from solutions. (C) 2003 Elsevier Ltd. All rights reserved., ELSEVIER SCI LTD, Jan. 2004, POLYMER, 45 (2), 409 - 421, doi;web_of_science

    Scientific journal

  • Molecular mobility of amorphous chain segments of ethylene-methyl methacrylate copolymer films as a function of temperature estimated by positron annihilation, X-ray diffraction, and C-13 NMR

    L Ma; CQ He; T Suzuki; M Azuma; YZ Bin; H Kurosu; M Matsuo

    The relationship between the morphology and the mechanical properties of copolymer ethylene-methyl methacrylate (EMMA) films with different MMA contents was investigated as a function Of temperature by using positron annihilation, X-ray diffraction, and C-13 solid-state NMR. To make clear the effect of MMA. side groups on the morphology and molecular mobility of EMMA as a function of temperature, the characteristics of EMMA were discussed together with those of copolymer (dimethylamino)ethyl methacrylate (EDAM) and branched polyethylene. Three kinds of transitions were confirmed by positron annihilation: the first at temperatures around -130 degreesC, the second around -40 degreesC, and the third around 50 degreesC. The first and the second transitions were due to the commencement of molecular motions, which can remove trapped electrons from their shallow potentials, while the third transition around 50 degreesC was attributed to the partial melting of unstable small crystallites. These transitions were in good agreement with the results obtained from differential scanning calorimetry (DSC) and X-ray measurements. Namely, the DSC curves of EMMA provided a peak around -25 to -30 degreesC corresponding to the second transition and a small peak around 43-48 degreesC corresponding to the third transition. Lifetime (tau3) showed no obvious change between branched polyethylene and EMMA-I melt films. This result can be explained within the framework of the spur model of Ps formation in terms of the trapping of positrons (and may be electrons) by the polar groups, -C=O, in EMMA., AMER CHEMICAL SOC, Oct. 2003, MACROMOLECULES, 36 (21), 8056 - 8065, doi;web_of_science

    Scientific journal

  • Oriented and thermal crystallization of poly(ethylene terephthalate)

    T Xu; YZ Bin; H Kurosu; M Matsuo

    The oriented and thermal crystallization of amorphous poly(ethylene terephthalate) (PET) films was investigated in terms of the morphological aspects. When the amorphous PET films were stretched up to the desired draw ratios in a hot water bath at 62, 72, and 80 degreesC, the birefringence of the specimens increased with increasing draw ratio (lambda). This tendency becomes most significant when the specimen was drawn in the bath at 62 degreesC. The storage modulus of the specimen drawn at 62 degreesC was higher than those of the specimens drawn at 72 and 80 degreesC. The exothermic peak in the DSC curves was observed clearly for the specimen drawn up to lambda=4 in the hot water bath at 80 degreesC, while the peak did not appear for the specimen drawn up to lambda=4 at 62 degreesC. Under an H-v polarization condition, light scattering patterns from the specimens drawn in the hot water bath showed four lobes at small azimuthal angles and four sharp streaks at large azimuthal angles. Such a profile was independent of the drawing temperatures from 62 to 80 degreesC. Based on the observed H-v patterns, a model was proposed by assuming the existence of a row-nucleated sheaf-like structure whose rows were preferentially oriented at a particular angle with respect to the stretching direction. The patterns calculated by using the above model were rather close to the patterns observed. This agreement implies that row-nucleated sheaf-like texture arises with lamellar overgrowth., SPRINGER-VERLAG, Jul. 2003, COLLOID AND POLYMER SCIENCE, 281 (7), 624 - 636, doi;web_of_science

    Scientific journal

  • A study of solvent exchange process in (ethylene-vinyl alcohol) copolymer gels by a proton nuclear magnetic resonance spectroscopy imaging method

    M Kanekiyo; M Kobayashi; Ando, I; H Kurosu; S Amiya

    The proton nuclear magnetic resonance (H-1 NMR) image patterns of (ethylene-vinyl alcohol) copolymer (EVOH)/dimethylsulfoxide (DMSO) gels with various ethylene contents were measured to elucidate the process of solvent exchange between DMSO and water in the gels soaked in water. The results of these experiments indicate that the rate of solvent exchange between DMSO and water in the gels increased with an increase in the ethylene content of EVOH copolymers. (C) 2002 Wiley Periodicals, Inc., JOHN WILEY & SONS INC, Oct. 2002, JOURNAL OF APPLIED POLYMER SCIENCE, 86 (2), 504 - 508, doi;web_of_science

    Scientific journal

  • Elongation-induced phase separation of poly(vinyl alcohol)/poly(acrylic-acid) blends as studied by C-13 CP/MAS NMR and wide-angle X-ray diffraction

    Q Chen; H Kurosu; L Ma; M Matsuo

    The membrane samples of poly(vinyl alcohol)/poly(acrylic-acid) (PVA/PAA) blend with different draw ratios were studied by both C-13 CP/MAS NMR and wide-angle X-ray diffraction (WARD) measurements. Phase separation induced by elongation of the sample was observed and the change of the phase structure with draw ratio was found to be dependent on the composition of the blend samples. (C) 2001 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, Feb. 2002, POLYMER, 43 (4), 1203 - 1206, web_of_science

    Scientific journal

  • C-13 NMR chemical shift and electronic structure of a three-dimensional polyacetylene crystal by ab initio tight binding MO theory

    K Fujii; S Kuroki; M Uchida; H Kurosu; Ando, I

    The NMR chemical shift of a three-dimensional polyacetylene crystal in the orthorhombic, form was calculated by a combination of ab initio tight-binding MO theory and the sum-over-states method of the chemical shift theory within the STO-3G minimal basis set, in order to elucidate the inter-molecular interaction effect of the C-13 NMR chemical shift and electronic structure, as associated with the crystallographic form. The effects of inter- and intra-chain on the C-13 NMR chemical shift and the electronic structure were reasonably evaluated. (C) 2002 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Jan. 2002, JOURNAL OF MOLECULAR STRUCTURE, 602, 3 - 8, web_of_science

    Scientific journal

  • Structural characterization of drawn (ethylene-vinyl alcohol) copolymer by high-resolution solid-state C-13 NMR

    H Kurosu; K Fukushima; M Matsuo; Ando, I; S Amiya

    High-resolution solid-state C-13 NMR spectra of drawn (ethylene-vinyl alcohol) copolymer (EVOH) and their C-13 spin-lattice relaxation times (T-1) were measured in order to elucidate the structure and dynamics of EVOH in the drawn state. It is found that the C-13 chemical shift of the CH carbon for drawn EVOH moved upfield as compared with that of undrawn EVOH. Further, the mobility for the CH carbons of low molecular motion components are increased by drawing the EVOH sample. From these experimental results, the changes in the structure and dynamics of the drawn EVOH sample can be elucidated. (C) 2002 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Jan. 2002, JOURNAL OF MOLECULAR STRUCTURE, 602, 233 - 237, web_of_science

    Scientific journal

  • Polar packing structure in copolyester comprising 4-hydroxy benzoic acid and 6-hydroxy-2-naphthoic acid as studied by high resolution solid state C-13 NMR spectroscopy and quantum chemistry

    M Kurosu; T Ookubo; H Tuchiya; Ando, I; J Watanabe

    The copolyester comprising 73 mol% of 4-hydroxy benzoic acid and 27 mol% of 6-hydroxy-2-naphthoic acid, so called Vectra, was known to show the strong second harmonic generation (SHG) when it has a high molecular weight. Using high-resolution solid state C-13 NMR, we investigated the intermolecular interaction in this series of copolyesters with different inherent viscosities. The observed C-13 NMR chemical shifts of carbonyl carbon moved downfield as the inherent viscosity is increased. The trend is similar to that observed in the inherent viscosity dependence of the SHG activity, showing that the downfield movement of the chemical shift is related to the polar structure. Ab initio GIAO-CHF calculations of NMR chemical shifts (NMR shieldings) were carried out for seven-molecules models with and without the polarity. The result confirms the assignment of the downfield movement of the chemical shifts to the transformation from the nonpolar structure to the polar structure. (C) 2001 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Nov. 2001, JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, 574, 153 - 162, web_of_science

    Scientific journal

  • Ultra-drawing of low molecular weight polyethylene - ultra-high molecular weight polyethylene blend films prepared by gelation/crystallization from semi-dilute solutions

    YZ Bin; L Ma; R Adachi; H Kurosu; M Matsuo

    Greatest drawability was studied for blend films with branched low molecular weight polyethylene (B-LMWPE) and ultra-high molecular weight polyethylene (UHMWPE) prepared by gelation/crystallization from solutions. The morphology of B-LMWPE-UHMWPE dry gel film and its deformation mechanism were mainly estimated by using differential scanning calorimeter, small-angle X-ray scattering, wide-angle X-ray diffraction and solid-state C-13 NMR. The detailed analysis was carried out for the blend films including large amounts of B-LMWPE. As a result, it was found that the UHMWPE and B-LMWPE were crystallized separately from the mixed solution. The greatest drawability was attributed to a suitable number of entanglements between UHMWPE crystal lamellae that are highly oriented with their large flat faces parallel to the film surface. These entanglements play an important role to transmit the drawing force as intermolecular cross-links and ensured smooth crystal transition of UHMWPE from a folded to a fibrous. In this process, large amount of B-LMWPE is thought to be almost independent of the ultra-drawing behavior of UHMWPE, since the domains of UHMWPE and B-LMWPE within the blend have no interaction and B-LMWPE crystallites take almost a random orientation. (C) 2001 Published by Elsevier Science Ltd., ELSEVIER SCI LTD, Sep. 2001, POLYMER, 42 (19), 8125 - 8135, web_of_science

    Scientific journal

  • Morphology and mechanical properties of copolymer ethylene-methyl methacrylate films as a function of temperature estimated by polarized light scattering, X-ray, and 13C NMR

    Lin Ma; Yuezhen Bin; Yuko Sakai; Qun Chen; Hiromichi Kurosu; Masaru Matsuo

    The relationship between the morphology and the mechanical properties of copolymer ethylene-methyl methacrylate (EMMA) was estimated as a function of temperature by using polarized light scattering, X-ray diffraction and 13C Solid-state NMR. All of these measurements revealed unstable crystallites within the EMMA films having a MMA content > 14 mol %, crystallinity less than 10%, and crystal size of about 3 nm. On the other hand, the ethylene sequences in the amorphous phase had an ordered arrangement rather than a random orientation. It is evident that these characteristics are due to the strong repulsion between MMA and ethylene. Namely, MMA side groups suppress the crystallization as an essential property of ethylene sequences consequently, the difficulty of accelerating the self-arrangement of ethylene sequences as crystallites leads to a local ordered arrangement of long ethylene sequences in the amorphous phase. The maximum draw ratio of the EMMA film reached 10 times at room temperature. A specimen with a draw ratio < 2 showed a reversible change of stress-strain curves up to 40 repetitions at room temperature. This behavior appears to be within the framework of ideal rubber elasticity. However, the stress at a fixed strain decreased with passing time as well as with increasing temperature. This behavior is completely out of the framework. Such inconsistency is due to the fact that small crystallites playing a cross-linking role became disrupted by chain slippage at a constant strain and at elevated temperature., 03 Jul. 2001, Macromolecules, 34 (14), 4802 - 4814, doi

    Scientific journal

  • Morphology and mechanical properties of swollen gels and dry gel films of poly(vinyl alcohol) prepared by crystallization from solutions under simultaneous biaxially stretching

    Y Bin; Y Tanabe; C Nakabayashi; H Kurosu; M Matsuo

    Simultaneous biaxial stretching was carried out by using poly(vinyl alcohol) (PVA) gel films which were prepared by crystallization from solutions in dimethyl sulfoxide (Me2SO) and water (H2O) mixtures. The Me2SO/H2O composition was set to be 70:30. The maximum biaxially draw ratio, 3 x 3, is much lower than 8.7 x 8.7 of ultra-high-molecular-weight polyethylene (UHMWPE) dry gel films. Even so, Young's modulus of the PVA film was almost equal to that of the UHMWPE. To address this problem, theoretical analysis was carried out using a three-dimensional model, in which the oriented crystalline layers are surrounded by an anisotropic amorphous phase and the strains of the two phases at the boundary are identical. Young's modulus was calculated by using the generalized orientation factors of crystallites and amorphous chain segments estimated from the orientation functions of crystallites and amorphous chain segments. The experimental values were lower than the calculated one. Such a disagreement between the experimental and calculated values was discussed in relation to the morphology estimated by high-resolution solid state C-13 NMR spectroscopy. Furthermore, the ultimate value of Young's modulus was estimated theoretically by assuming an ideal simultaneous biaxially stretched film with 100% crystallinity and the perfect orientation of the c-axes parallel to the film surface. The predicted value at absolute temperature was less than 13.5 GPa, suggesting the impossibility to produce high-modulus and high-strength PVA sheets. Incidentally, the stress-strain curves repeated up to 40 times of swollen gels with large amount of solvents >80% passed through the same hysteresis route indicating rubber elasticity. Such an interesting phenomenon was investigated in relation to crystallization by small angle light scattering under Hv polarization condition and X-ray diffraction. (C) 2000 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, Feb. 2001, POLYMER, 42 (3), 1183 - 1200, web_of_science

    Scientific journal

  • Structural and dynamic study of ethylene-vinyl alcohol copolymer gels by H-1 pulse NMR and solid-state C-13 NMR

    M Kanekiyo; M Kobayashi; Ando, I; H Kurosu; S Amiya

    H-1 pulse NMR and solid-state C-13 NMR spectra of ethylene-vinyl alcohol copolymer (EVOH) gels were measured as a function of ethylene content, and furthermore, the C-13 spin-lattice relaxation times (T-1) and the H-1 spin-spin relaxation times (T-2) have been measured, to elucidate the structure and dynamics of the mobile and immobile regions in the gels. From the H-1 pulse NMR experimental results, it is found that the H-1 T-2 signal is mainly composed of two or three binds of components with different molecular motions. The long T-2 component is assigned to correspond to the mobile region, which comes from the un-cross-linked region, the short T-2 component corresponds to the immobile region, which comes from the cross-linked region, and the intermediate T-2 component corresponds to the intermediate region between the mobile and immobile regions, which comes from the vicinity of the cross-linked region in the EVOH gel. Furthermore, from the solid state C-13 NMR experimental results, it is found that the formation of hydrogen bonds between the hydroxyl groups in vinyl alcohol parts of EVOH copolymers with high vinyl alcohol fraction and the formation of hydrophobic interactions between the methylene groups in ethylene parts of EVOH copolymers with high ethylene fraction contributes to its gel formation., AMER CHEMICAL SOC, Oct. 2000, MACROMOLECULES, 33 (21), 7971 - 7976, doi;web_of_science

    Scientific journal

  • Spatial distribution of paramagnetic Mn2+ ions in a composite PMAA gel with the application of an electric field as studied by H-1 NMR imaging method

    A Yamazaki; Y Hotta; H Kurosu; Ando, I

    The H-1 T-2 NMR images were observed for a transverse slice of a composite poly(methacrylic acid) hydrogel consisting of two parts with a different degree of crosslinking under the application of a 3 V DC electric field as a function of elapsed time by means of 270 MHz H-1 NMR imaging method. The H-1 T-2 (spin-spin relaxation time) NMR image was converted to the Mn2+ ion concentration image by using the relationship between the Mn2+ ion concentration and the H-1 T-2 value. From these experiments, the spatial distribution of Mn2+ ions in the gel under the application of a 3 V DC electric field were determined as a function of the elapsed time. From the results of the migration process of Mn2+ ions the crosslinking structure of the interfacial region between the two parts with a different degree of crosslinking was discussed. In addition, the formation process of a composite PMAA gel was observed with polymerization time by means of H-1 NMR imaging. (C) 2000 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Oct. 2000, JOURNAL OF MOLECULAR STRUCTURE, 554 (1), 47 - 53, web_of_science

    Scientific journal

  • A study of conformational stability of polyglycine and poly(L-alanine), and polyglycine/poly(L-alanine) blends in the solid state by C-13 cross-polarization/magic angle spinning NMR

    J Nakano; S Kuroki; Ando, I; T Kameda; H Kurosu; T Ozaki; A Shoji

    C-13 Cross-Polarizarion/Magic Angle Spinning nmr and T-1pH experiments of polyglycine (PG), poly(L-alanine) (PLA), and PG/PLA blends prepared from dichloroacetic acid solution have been carried out, in order to elucidate the conformational stability of these polypeptides in the solid state. From these experimental results, it was clarified that the conformations of PG and PLA in their blends are strongly influenced by intermolecular hydrogen-bonding interactions that cause their miscibility at the molecular level. (C) 2000 John Wiley & Sons, Inc., JOHN WILEY & SONS INC, Aug. 2000, BIOPOLYMERS, 54 (2), 81 - 88, web_of_science

    Scientific journal

  • C-13 NMR chemical shift as a probe for estimating the conformation of aromatic groups in the solid state. 1. Biphenyls

    S Ando; T Hironaka; H Kurosu; Ando, I

    The relationships between C-13 NMR chemical shifts of aromatic carbons and the inter-ring torsion angles (theta) of two phenyl rings in biphenyl and its substituted derivatives were systematically examined. The chemical shifts of C1, C2 and C6 carbons (delta(C1), delta(C2) and delta(C6)) of she biphenyl group in the solid state show systematic correlations with theta when the substituent shielding effects are removed from the solid chemical shifts by subtracting the solution chemical shifts or subtracting the substituent shielding parameters. The substituent parameters deduced from substituted benzenes are utilized for the calculation. An increase in delta(C1), delta(C2) or delta(C6) (high-frequency displacement of the signals) corresponds to an increase in theta. In particular, delta(C6) can be a good measure of theta when no substituents are attached to C6. The isotropic nuclear shielding calculated using ab initio molecular orbital theory with the GIAO-CHF method for the biphenyl agree well with the experimental results. The relationships between the C-13 chemical shifts and the inter-ring torsion angle can be used to estimate the conformation of biphenyl groups incorporated into aromatic and/or liquid crystalline compounds and polymers. Copyright (C) 2000 John Wiley & Sons, Ltd., JOHN WILEY & SONS LTD, Apr. 2000, MAGNETIC RESONANCE IN CHEMISTRY, 38 (4), 241 - 250, web_of_science

    Scientific journal

  • A structural study of (ethylene-vinyl alcohol) copolymers by high-resolution solid-state C-13 NMR

    M Kanekiyo; M Kobayashi; Ando, I; H Kurosu; S Amiya

    High-resolution solid-state C-13 NMR spectra of (ethylene-vinyl alcohol) copolymers (EVOH) with various ethylene contents in the solid-state and their C-13 spin-lattice relaxation times, T-1, were measured, in order to elucidate the structure and dynamics of the copolymers. From these experimental results, the structural change of the EVOHs with changes of the ethylene content was successfully elucidated. Further, it is found that the C-13 T-1 for the CH carbon of the vinyl alcohol unit is mainly composed of two components. The fractions of short and long T-1 components increase and decrease with an increase in the ethylene fraction, respectively. From these experimental results, it can be said that changes of the ethylene content in the copolymers lead to large changes in their structure and dynamics. (C) 1999 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, Mar. 2000, POLYMER, 41 (7), 2391 - 2404, web_of_science

    Scientific journal

  • Structural characterization of C-13-labeled n-tetracosane adsorbed on the surface of silica gel by high-resolution solid-state C-13 NMR spectroscopy

    H Kurosu; K Takahashi; D Inoue; Ando, I

    C-13 CP/MAS and PST/MAS spectra of 10% C-13-labeled n-tetracosane adsorbed on the surface of silica gel were measured by means of high-resolution solid-state C-13 NMR. From these experimental results, it is found that adsorbed n-tetracosane is in three regions with different molecular motion. in the immobile region, n-tetracosane takes a layer structure with triclinic-like form, in the mobile region, n-tetracosane is undergoing fast transition between trans and gauche conformations and fast rotation along the chain axis. (C) 2000 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Jan. 2000, JOURNAL OF MOLECULAR STRUCTURE, 516 (2-3), 177 - 184, web_of_science

    Scientific journal

  • Structural characterization of stearic acid in the crystalline state by the cross polarization in solid state C-13 NMR

    S Arata; H Kurosu; S Kuroki; Ando, I

    C-13 cross polarization/magic angle spinning (CP/MAS) NMR spectra of stearic acid with the crystallographic form C, deuterated the methyl and methylene groups besides a proton in the carboxylic group, were measured as a function of the contact time, in order to obtain the cross relaxation rate (1/T-CH) between the methylene carbons and protons in the compound. From these experimental results, it was found that the 1/T-CH values for the methylene carbons are proportional to r(av)(-6), which is the averaged atomic distance between any specified carbon and protons. This means that the CP experiment provides a geometrical information using the partially deuterated molecules. (C) 1999 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Dec. 1999, JOURNAL OF MOLECULAR STRUCTURE, 513 (1-3), 133 - 138, web_of_science

    Scientific journal

  • Diffusional behavior of n alkanes in the rotator phase as studied by pulse field-gradient spin-echo H-1 NMR method

    H Yamakawa; S Matsukawa; H Kurosu; S Kuroki; Ando, I

    Self-diffusion coefficients, D, of n-C21H44, n-C23H48, n-C24H50, n-C28H58, n-C32H66, and n-C34H70 were measured in the rotator phase and the liquid phase over a wide range of temperatures by using pulse field-gradient spin-echo H-1 NMR method, in order to clarify diffusional behavior of the n-alkanes in the rotator phase. From these experimental results it was found that the self-diffusion coefficients of these n-alkanes in the rotator phase and the liquid phase are decreased with a decrease in temperature with different slopes, and at the transition temperature in going from the liquid phase to the rotator phase do not change with a transitionally large decrease. From the Arrhenius plot of diffusion coefficient against temperature, the activation energies for diffusion of n-C24H50, n-C32H66, and n-C34H70 in the rotator phase were obtained to be 19.9, 33.9, and 35.9 kcal/mol, respectively, and on the other hand those in the liquid phase to be 4.8, 4.8, and 5.1 kcal/mol, respectively. Further, the corresponding values of n-C21H44, n-C23H48, and n-C28H58 in the liquid phase were obtained to be 4.7, 4.6, and 4.9 kcal/mol, respectively. It was found that the activation energy for diffusion of n-alkanes in the rotator phase is increased with an increase in the carbon number and is much larger than that in the liquid phase. Further, it was found that in the rotator phase of a n-C24H50 single crystal, the diffusion coefficients in direction perpendicular and parallel to the long chain axis were determined to be 2.70x10(-6) and 1.64x10(-6) cm(2)/s, respectively. (C) 1999 American Institute of Physics. [S0021-9606(99)51239-7]., AMER INST PHYSICS, Oct. 1999, JOURNAL OF CHEMICAL PHYSICS, 111 (15), 7110 - 7115, web_of_science

    Scientific journal

  • An MO study on C-13 NMR chemical shift and the electronic structure of a three-dimensional polymer crystal by ab initio tight-binding MO theory I. Polyethylene crystal

    M Uchida; Y Toida; H Kurosu; Ando, I

    Formulae for calculating the NMR chemical shift of a three-dimensional (3D) polymer crystal were derived by a combination of ab initio tight-binding MO theory and the sum-over-states method of the chemical shift theory. This formalism was applied to the calculation of the C-13 NMR chemical shift of 3D polyethylene chains in the orthorhombic and the monoclinic crystallographic forms by using the STO-3G minimal basis set. The effects of inter- and intra-chain interactions on the C-13 NMR chemical shift and the band structure were evaluated with a change by means of the a and c axes and the b axis in the lattice constants. The calculated results explain reasonably the experimental data. (C) 1999 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Sep. 1999, JOURNAL OF MOLECULAR STRUCTURE, 508 (1-3), 181 - 191, web_of_science

    Scientific journal

  • Diffusion processes in polymer gels as studied by pulsed field-gradient spin-echo NMR spectroscopy

    S Matsukawa; H Yasunaga; C Zhao; S Kuroki; H Kurosu; Ando, I

    In order to study the diffusional behavior of molecules or polymers in a polymer network with a wide range of the diffusion coefficients, we have developed two kinds of PGSE NMR probes with a maximum strength of the field gradient ranging from 700 to 2000 G cm(-1). By using these probes it is possible to measure the diffusion coefficient D with the order of about 10(-9) cm(2) s(-1). These NMR probes lead to sophisticated knowledge concerning the diffusional behavior of molecules in polymer gels. This review article is concerned with a series of studies on the diffusional behavior of polymer gel systems by means of novel PGSE NMR probes. (C) 1999 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, Sep. 1999, PROGRESS IN POLYMER SCIENCE, 24 (7), 995 - 1044, web_of_science

  • Conformational analysis of the biphenyl moiety of dimer liquid crystals in the solid state by high-resolution solid-state C-13 NMR and ab initio GIAO-CHF calculations

    RN Shimizu; H Kurosu; Ando, I; A Abe; H Furuya

    High-resolution C-13 NMR spectra of alpha,omega-bis[(4,4'-cyanobiphenylyl)oxy]alkanes (CBA-n, n = 7, 9 and 10) were measured in chloroform solution and in the polycrystalline state. The spectra of the samples in solution are essentially the same; in the polycrystalline state, on the other hand, the spectrum of CBA-9 presents some differences in the aromatic carbon region in relation to those of CBA-7 and CBA-10' which are similar. Therefore, ab initio GIAO-CHF calculations were carried out and an analysis of the conformation of the biphenyl moiety was attempted by comparing the results of the calculations with the measured high-resolution solid-state C-13 NMR spectra. From these results it was concluded that the torsion angle for the biphenyl moiety of CBA-7 and CBA-10 stays at about 40 degrees. For CBA-9 it is suggested that conformers with torsion angles of about 30 degrees and 60 degrees are also present. Copyright (C) 1999 John Wiley & Sons, Ltd., JOHN WILEY & SONS LTD, Jul. 1999, MAGNETIC RESONANCE IN CHEMISTRY, 37 (7), 479 - 483, web_of_science

    Scientific journal

  • C-13-NMR chemical shift tensor and hydrogen-bonded structure of glycine-containing peptides in a single crystal

    N Takeda; S Kuroki; H Kurosu; Ando, I

    C-13-nmr chemical shift tensor components are reported for a C-13-labeled Gly(1) amide carbonyl carbon of a glycylglycine (Gly(1)Gly(2)) single crystal, a GlyGly . HNO3 single crystal and a GlyGly . HCl . H2O single crystal, for which the three-dimensional crystal structures have already been determined by x-ray diffraction. The tensor components were measured by changing the angle between the crystal plane and the applied magnetic field by using a goniometer designed in this work for use in conventional C-13 cross-polarization/magic angle spinning nmr probe. From these experimental data, the principal values of the C-13 chemical shift tensor and its directions for the Gly(1) amide carbonyl carbon were determined It was found that the C-13 chemical shift tensor components (delta(11), delta(22), and delta(33)) for the Gly(1) amide carbonyl carbon in GlyGly and GlyGly . HNO3 with a >NH ... O=C< type of hydrogen bond depend on the hydrogen-bond length and the directions of the delta(22) components of these peptides are along the hydrogen-bonded >C=O bond axis. In addition, the magnitude of the deviation from the bond axis depends on the hydrogen-bond angle. Further the experimental result for GlyGly . HCl . H2O with a-O-H ... O=C< type of hydrogen bond was discussed. (C) 1999 John Wiley & Sons, Inc., JOHN WILEY & SONS INC, Jul. 1999, BIOPOLYMERS, 50 (1), 61 - 69, web_of_science

    Scientific journal

  • Morphology and mechanical properties of low-molecular-weight polyethylene and ultrahigh-molecular-weight polyethylene films drawn up to 200-fold

    Yuezhen Bin; Miwako Fukuda; Hiromichi Kurosu; Masaru Matsuo

    Ultrahigh-molecular-weight polyethylene (UHMWPE) and low-molecular-weight polyethylene (LMWPE) blend films were prepared by gelation/crystallization from solutions. UHMWPE with the viscosity-average molecular weight (M̄v) of 6×106 and three kinds of LMWPE with M̄v < 5×104 were used. The LMWPE/ UHMWPE compositions chosen were 1/1, 2/1, 4/1 and 9/1. The resulting blend gels with the 9/1 composition (10% UHMWPE content) became films by evaporating the solvents, although LMWPE homopolymer gels have no ability to form films. The films with the above compositions could be readily elongated up to 200-fold in a hot oven. Such high elongation is assumed to be due to the existence of a suitable level of entanglements between UHMWPE and LMWPE chains. The orientational degree of LMWPE crystallites became poorer as the LMWPE content in the blend film increased, indicating a decrease in the number of entanglements. The storage modulus of the blend films at the same draw ratio decreased as the LMWPE content increased. The storage modulus of the 1/1 blend film with λ = 200 reached about 50 GPa at 20°C but the storage modulus decreased drastically with further increase in the LMWPE content: the value of the 9/1 blend film with λ = 200 was less than 10 GPa. This means that a suitable level of entanglements between LMWPE and UHMWPE chains plays an important role in transmitting the drawing force effectively and promoting the orientational degree of the c-axis, owing to the crystal transformation from a folded to a fibrous type., John Wiley and Sons Ltd, 1999, Macromolecular Symposia, 147, 1 - 14, doi

    Scientific journal

  • Hydrogen bonding interactions in polyureas as studied by variable-temperature high-resolution H-1 NMR spectroscopy

    Q Chen; G Yang; Y Wang; Wu, X; H Kurosu; Ando, I

    Variable-temperature high-resolution H-1 NMR experiments on four polyurea samples with different kinds of hard segments and soft segments were carried out in dimethylformamide solution. From these experimental results, it was found that the NH groups of the hard segments of the polymers form different styles of hydrogen-bonds between the amide group of dimethylformamide and the oxygen atom of the soft segment, and that the formation of hydrogen-bonds between the NH groups and oxygen atoms greatly depends on the molecular weight of the soft segment of the polymers. (C) 1998 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Nov. 1998, JOURNAL OF MOLECULAR STRUCTURE, 471 (1-3), 183 - 188, web_of_science

    Scientific journal

  • A study on dynamics of water in crosslinked poly(N-isopropylacrylamide) gel by nmr spectroscopy

    N Tanaka; S Matsukawa; H Kurosu; Ando, I

    dynamics of crosslinked poly (N-isopropylacrylamide) gel have been studied by means of pulsed-gradient spin-echo (PGSE) H-1 nuclear magnetic resonance (n.m.r.), pulse H-1 n.m.r. and H-1 n.m.r. imaging. The selfdiffusion coefficients of HDO (D-HDO) in D2O (containing a small amount of HDO) in the gels with various degree of swellings were determined by the PGSE H-1 n.m.r. method. From these experimental results, it was found that the D-HDO is decreased as the degree of swelling is decreased, and D-HDO in the gels with a constant degree of swelling in going from 20 to 45 degrees C is transitionally decreased at about 32 degrees C, which corresponds to the phase transition temperature. From the detailed analysis of proton spin-spin relaxation time T-2 determined by the pulse H-1 n.m.r. method, the process of the volume phase transition of the gel has been elucidated. Furthermore, spatial information about the molecular motion of water in the gel sample was obtained by T-2 enhanced H-1 n.m.r. imaging. (C) 1998 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, Sep. 1998, POLYMER, 39 (20), 4703 - 4706, web_of_science

    Scientific journal

  • A study on dynamics of water in crosslinked poly(N-isopropylacrylamide) gel by nmr spectroscopy

    N Tanaka; S Matsukawa; H Kurosu; Ando, I

    dynamics of crosslinked poly (N-isopropylacrylamide) gel have been studied by means of pulsed-gradient spin-echo (PGSE) H-1 nuclear magnetic resonance (n.m.r.), pulse H-1 n.m.r. and H-1 n.m.r. imaging. The selfdiffusion coefficients of HDO (D-HDO) in D2O (containing a small amount of HDO) in the gels with various degree of swellings were determined by the PGSE H-1 n.m.r. method. From these experimental results, it was found that the D-HDO is decreased as the degree of swelling is decreased, and D-HDO in the gels with a constant degree of swelling in going from 20 to 45 degrees C is transitionally decreased at about 32 degrees C, which corresponds to the phase transition temperature. From the detailed analysis of proton spin-spin relaxation time T-2 determined by the pulse H-1 n.m.r. method, the process of the volume phase transition of the gel has been elucidated. Furthermore, spatial information about the molecular motion of water in the gel sample was obtained by T-2 enhanced H-1 n.m.r. imaging. (C) 1998 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, Sep. 1998, POLYMER, 39 (20), 4703 - 4706, web_of_science

    Scientific journal

  • A structural and dynamic study of poly(vinyl alcohol) in the gel state by solid-state C-13 NMR and H-1 pulse NMR

    M Kanekiyo; M Kobayashi; Ando, I; H Kurosu; T Ishii; S Amiya

    H-1 pulse NMR and high-resolution solid-state C-13 NMR spectra of poly(vinyl alcohol) (PVA) gel were measured to clarify the structure and dynamics of the immobile component of the gel. From H-1 pulse NMR experiments, it was found that the T-2 Signal is mainly composed of three components. The long T-2 component was assigned to the mobile component which comes from the non-crosslinked region, the intermediate T-2 component corresponds to the intermediate immobile component which comes from the vicinity of the crosslinked region, and the short T-2 component corresponds to the immobile component which comes from the crosslinked region in the PVA gel. From high-resolution solid-state C-13 NMR experiments, the mechanism of gel formation was satisfactorily elucidated. Further, dynamic viscoelastic modulus measurements were carried out. These experimental results were satisfactorily explained on the basis of the NMR results. (C) 1998 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE BV, Jun. 1998, JOURNAL OF MOLECULAR STRUCTURE, 447 (1-2), 49 - 59, web_of_science

    Scientific journal

  • Self-diffusion behavior of solvents in polypeptide gel as studied by pulsed-gradient spin-echo H-1 NMR spectroscopy

    CH Zhao; S Matsukawa; H Kurosu; Ando, I

    AMER CHEMICAL SOC, May 1998, MACROMOLECULES, 31 (9), 3139 - 3141, web_of_science

    Scientific journal

  • High resolution C-13 NMR studies for crystalline and liquid crystalline phases of PB-18 polyester composed of 4,4 '-dihydroxybiphenyl and octadecanedioic acid

    M Tokita; M Sone; H Kurosu; Ando, I; J Watanabe

    Main-chain liquid crystalline PB-18 polyester composed of 4,4'-dihydroxybiphenyl and octadecanedioic acid forms two distinct crystalline phases, K-1 and K-2, and smectic H (S-H) phase in the order of increasing temperature. The detailed structures of the three phases were studied by C-13 solid-state NMR spectroscopy with variable temperature accessories. With a comparison of the observed C-13 chemical shifts to the calculated C-13 NMR shieldings by FPT-INDO method, the conformations of the mesogenic moiety and alkylene spacer are discussed among these three phases. (C) 1998 Elsevier Science B.V., ELSEVIER SCIENCE BV, May 1998, JOURNAL OF MOLECULAR STRUCTURE, 446 (3), 215 - 221, web_of_science

    Scientific journal

  • A study of the dynamics of n-alkane in the rotator phase by using the pulse-field-gradient spin-echo H-1 NMR method

    H Yamakawa; S Matsukawa; H Kurosu; S Kuroki; Ando, I

    The self-diffusion coefficient (D) and H-1 spin-spin relaxation time (T-2) of n-alkane, n-C24H50, were measured in the rotator and liquid phases over a wide range of temperatures by means of pulse-field-gradient spin-echo H-1 NMR, in order to clarify the molecular motion of the alkane in the rotator and liquid phases. With a decrease in temperature from the liquid phase (65 to 51 degrees C) to the rotator phase (50 to 45 degrees C), the temperature dependence of D is abruptly changed at the transition temperature and the slope for the rotator phase is much larger than that for the liquid phase. This means that the mechanism of their diffusional processes is different. Further, it is found that the temperature dependence of the H-1 T-2 shows similar behavior. (C) 1998 Elsevier Science B.V., ELSEVIER SCIENCE BV, Feb. 1998, CHEMICAL PHYSICS LETTERS, 283 (5-6), 333 - 336, web_of_science

    Scientific journal

  • Chapter 9 Polyethylene and paraffins

    Takeshi Yamanobe; Hiromichi Kurosu

    1998, Studies in Physical and Theoretical Chemistry, 84 (C), 327 - 349, doi

    Scientific journal

  • Chapter 16 Electrically-Conducting Polymers

    Hiromichi Kurosu

    1998, Studies in Physical and Theoretical Chemistry, 84 (C), 589 - 611, doi

    Scientific journal

  • Image analysis of the spatial distribution of paramagnetic Mn2+ ions in a PMAA gel with the application of an electric field by an 1H n.m.r. imaging method

    Aki Yamazaki; Yoshio Hotta; Hiromichi Kurosu; Isao Ando

    The 1H T2 images for a transverse slice of a PMAA hydrogel with paramagnetic Mn2+ ions under the application of a 3 V DC electric field were observed as a function of elapsed time by means of 270 MHz 1H n.m.r. imaging. By using the relationship between the concentration of Mn2+ ions and the 1H T2 value of water in the gel obtained by 1H pulse n.m.r., the 1H T2 image was converted to the Mn2+ ion concentration image. From these experiments, the spatial distribution of paramagnetic Mn2+ ions in the gel under the application of a 3 V DC electric field was obtained as a function of the elapsed time. © 1997 Elsevier Science Ltd. All rights reserved., Elsevier BV, 1998, Polymer, 39 (8-9), 1511 - 1514, doi

    Scientific journal

  • Structures and dynamics of polymer gels observed by H-1 NMR imaging and H-1 PGSE NMR methods

    Ando, I; H Kurosu; S Matsukawa; A Yamazaki; Y Hotta; N Tanaka

    Structure and dynamics of hydropolymer gel systems have been elucidated microscopically and macroscopically by means of H-1 NMR imaging method and pulse-field gradient spin echo (PGSE) H-1 NMR method. Further, it was demonstrated that H-1 NMR imaging and H-1 PGSE NMR methods are very powerful means for elucidating structure and dynamics of polymer gels., JOHN WILEY & SONS LTD, 1998, WILEY POLYMER NETWORKS GROUP REVIEW SERIES, VOL 1 - CHEMICAL AND PHYSICAL NETWORKS, 331 - 346, web_of_science

    International conference proceedings

  • Structural Studies of Hydrogen-bonded Peptides and Polypeptides by Solid-state NMR

    N. Asakawa; T. Kameda; S. Kuroki; H. Kurosu; S. Ando; I. Ando; A. Shoji

    1998, Annual Reports on NMR Spectroscopy, 35 (C), 55 - 137, doi;scopus;scopus_citedby

    Scientific journal

  • Structure of peptides and polypeptides in the solid state as elucidated by NMR chemical shift

    Ando, I; T Kameda; N Asakawa; S Kuroki; H Kurosu

    It is reviewed that through the observation of solid-state C-13 NMR chemical shift, the main-chain conformation and hydrogen-bonded structure of peptides, polypeptides and proteins in the solid state have been successfully elucidated, and the combination of solid stale C-13 NMR and chemical shift calculation by quantum chemistry is a powerful means for the structural characterization. Furthermore, it is briefly introduced that solid state NMR of N-15 and O-17 nuclei is very useful for obtaining information about hydrogen-bonded structure. This review article is communicated on the basis of our recent works on structural characterization of peptides and polypeptides including proteins in the solid state by high-resolution solid-state NMR spectroscopy and its combination with quantum chemical calculation. (C) 1998 Elsevier Science B.V., ELSEVIER SCIENCE BV, Jan. 1998, JOURNAL OF MOLECULAR STRUCTURE, 441 (2-3), 213 - 230, web_of_science

    Scientific journal

  • Spatial information on a polymer gel as studied by H-1-NMR imaging: 4. Shrinkage by the application of an alternating electric field to a polymer gel

    Y Hotta; T Shibuya; H Yasunaga; H Kurosu; Ando, I

    We have measured the spatial distribution of H-1 spin density and H-1 spin-spin relaxation timer T-2, of water molecules in a crosslinked poly(methacrylic acid) (PMAA) gel under an alternating current (AC) electric field by means of proton nuclear magnetic resonance imaging. The experimental results show that a cylindrical gel shrinks to a cylindrical shape at long elapsed time after the application of an AC electric field, and that the H-1 spin densities on both electrode sides of the gel are high and the mobilities are low. The translational behavior of water molecules in the gel during shrinkage processes under an AC electric field is discussed at the molecular level. (C) 1998 Elsevier Science Ltd. All rights reserved., ELSEVIER SCI LTD, 1998, POLYMER GELS AND NETWORKS, 6 (1), 1 - 11, web_of_science

    Scientific journal

  • Conformational behaviour of poly(aspartic acid) and its sodium salt in the solid state as studied by high-resolution solid-state C-13-NMR spectroscopy

    PX Wang; S Matsukawa; T Kameda; H Kurosu; Ando, I

    High-resolution C-13 CP/MAS NMR spectra of poly(aspartic acid) (PAA) and its sodium salt (PAANa) obtained with various neutralization numbers, n ( = [COONa]/[COOH + COONa], where [x] is the molar concentration of x), have been measured over a wide range of temperatures, in order to elucidate the conformation and its stability in the solid state. From these experimental results it was found that, at room temperature (25 degrees C), the main chain of PAA takes a mixture of right-handed alpha (alpha(R))-helix, omega-helix and beta-sheet forms and, with an increase in temperature from 25 degrees C to 180 degrees C, changes from alpha(R)-helix form and omega-helix form to beta-sheet forms. On the other hand, the main chain of PAANa takes the right-handed omega(R)-helix form in the temperature range from 25 degrees C to 210 degrees C. With a decrease in the neutralization number, PAANa changes to PAA and the NMR spectra are correspondingly changed. (C) 1997 Elsevier Science B.V., ELSEVIER SCIENCE BV, Dec. 1997, JOURNAL OF MOLECULAR STRUCTURE, 435 (3), 229 - 234, web_of_science

    Scientific journal

  • Solid-state variable-temperature H-1 MAS NMR studies on deuterated polyethylene

    Q Chen; H Hurosu; Ando, I; Wu, X

    Solid-state varible-temperature/magic angle spinning(VT/MAS) H-1 NMR measurements were carried out on deuterated polyethylene. From these experimental results it was found that the H-1 chemical shift induced by conformational and morphological changes of the polyethylene sample is within the linewidth of approximate to 0.5 ppm. Furthermore, from MAS/dipolar decoupling experiments it was found that the resonance frequency of the proton varies linearly with the inverse square of the deuterium decoupling power. This experimental finding is discussed theoretically. (C) 1997 Elsevier Science B.V., ELSEVIER SCIENCE BV, Feb. 1997, SOLID STATE NUCLEAR MAGNETIC RESONANCE, 7 (4), 319 - 325, web_of_science

    Scientific journal

  • Orientational ordering of a dimer liquid crystal by high-resolution solid-state C-13 NMR spectroscopy

    RN Shimizu; H Kurosu; Ando, I; A Abe; H Furuya; S Kuroki

    The ordering of a dimer liquid crystal, alpha,omega-bis[(4,4'-cyanobiphenylyl)oxy]decane (CBA-IO), was studied by variable-temperature high-resolution solid-state C-13 NMR. A large transitional change of the C-13 chemical shift was observed on going from the isotropic to the nematic phase due to uniaxial alignment of the molecule. The principal values of the C-13 chemical shift tensor have been determined by the Herzfeld-Berger method for CBA-IO itself. The molecular axis is assumed to lie parallel to the line connecting the centers of both mesogenic cores, and the evaluation of the order parameters along the molecular axis, (S-zz), mesogene axis (S-zz(ring)) and C-gamma-C-epsilon, axis (S-zz(C nu-C epsilon)) was attempted here, using the obtained isotropic C-13 chemical shift and principal values of the C-13 chemical shift tensor, and taking into account the conformational behavior of the flexible spacer in the frame of rotational isomeric state (RIS) approach. The order parameter of the molecule S-zz increased from 0.79 to 0.89 with decrease of 17.5 degrees C in temperature from nearby the nematic-isotropic transition point. S-zz(ring) increased from 0.74 to 0.80 with decrease of temperature whereas S-zz(C gamma-C epsilon) and the conformation of the spacer was essentially unaltered in the same temperature range., SOC POLYMER SCIENCE JAPAN, 1997, POLYMER JOURNAL, 29 (7), 598 - 602, web_of_science

    Scientific journal

  • Hydrogen-bonded structure and C-13 NMR chemical shift tensor of amino acid residue carbonyl carbons of peptides and polypeptides in the crystalline state .1.

    T Kameda; N Takeda; S Kuroki; H Kurosu; S Ando; Ando, I; A Shoji; T Ozaki

    C-13 chemical shift tensor components (delta(11) delta(22) and delta(33)) Of glycine (Gly), L-valine (Val), L-leucine (Leu), and L-asparagine (Asp) residue carbonyl carbons (C = O) of peptides and polypeptides covering a wide range of hydrogen-bond lengths (R(N-O)) in the crystalline state have been measured by slow magic-angle-spinning solid-state C-13 NMR. From these experiments, it is found that delta(22), which lies approximately along the amide C = O bond, moves linearly downfield with a decrease in R(N-O) and the slope and intercept of the variation of delta(22) against R(N-O) depend on the amino acid residue. Using this relationship, the R(N-O) values for polypeptides were determined by observation of the 822 Of the guest Gly residue incorporated into host polypeptides. delta(11), and delta(33) are found to be insensitive to the change in R(N-O) and amino acid residues. Moreover, it is found that the sum of delta(11) and delta(33) is almost constant (337.5 +/- 3.5 ppm) and is independent of the amino acid residue. The quantum-chemical calculation on the C-13 shielding constant for a peptide model compound was carried out by the finite perturbation theory within the INDO framework. This calculation acceptably explains the experimental results., ELSEVIER SCIENCE BV, Oct. 1996, JOURNAL OF MOLECULAR STRUCTURE, 384 (1), 17 - 23, web_of_science

    Scientific journal

  • Solid-state C-13 MAS NMR studies of hyper-cross-linked polystyrene resins

    RV Law; DC Sherrington; CE Snape; Ando, I; H Kurosu

    C-13 CP/MAS NMR techniques have been used to evaluate the structure of four hyper-cross-linked polystyrene resins. Single-pulse excitation (SPE) C-13 spectra have allowed the various types of carbon atoms present in the resins to be quantified, and similarly H-1 CRAMPS spectra have facilitated quantification of the various hydrogen atom types. Two hyper-cross-linked resins prepared by exhaustive methylene bridging of conventional lightly cross-linked styrene-divinylbenzene resins have very high quaternary aromatic carbon contents. These can be explained adequately only if vert high levels of double methylene bridging of aromatic groups occurs. Approximately 10% of aromatic groups also retain a chloromethyl group from incomplete methylene bridging. Two further hyper-cross-linked resins reportedly prepared from conventional heavily cross-linked divinylbenzene (55% technical grade) resins appear in one instance to exploit residual unreacted double bonds (and possibly additional divinylbenzene) to generate the secondary cross-links, and in another to use SOCl2/Lewis acid to introduce very high levels of sulfoxide secondary cross-links. Dynamic NMR experiments suggest that the latter two hyper-cross-linked species retain more flexibility and mobility than those prepared via more conventional methylene bridging techniques., AMER CHEMICAL SOC, Sep. 1996, MACROMOLECULES, 29 (19), 6284 - 6293, web_of_science

    Scientific journal

  • Structural and dynamical analyses of small and large molecules in the solid state by high resolution solid state NMR

    H Kurosu; Ando, I

    The application of high-resolution solid-state NMR spectroscopy to structural and dynamical analyses of solid peptides, polypeptides, calixalene, conductive polymers, polyesters and poly (ethylene oxide) in the solid state have been introduced. It has been demonstrated that the high-resolution solid-state NMR spectroscopy is a very powerful means for elucidating the structure and dynamics of molecules in the solid state., SOC SYNTHETIC ORGANIC CHEM JPN, May 1996, JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 54 (5), 367 - 374, web_of_science

    Scientific journal

  • Chemical modification of monolithic poly(styrene-divinylbenzene) PolyHIPE(R) materials

    NR Cameron; DC Sherrington; Ando, I; H Kurosu

    Monolithic samples of highly porous poly(styrene/DVB) PolyHIPE(R) have undergone a number of electrophilic aromatic substitution reactions, namely sulfonation, nitration and bromination. Mild, hydrophobic reagents and homogeneous reaction conditions were sought in an effort to achieve uniform chemical modification, to a reasonable degree of substitution, throughout the large polymeric structures. Thus, sulfonation was Carried out with lauroyl sulfate in cyclohexane, nitration with tetrabutylammonium nitrate-trifluoroacetic anhydride (TBAN-TFAA) in dichloromethane and bromination with bromine-stannic chloride in dichloromethane. An average degree of sulfonation of 2.4 mmol g(-1) was achieved, with a drop in sulfonic acid content of approximately 1 mmol g(-1) from surface to centre. Nitration occurred to a lesser extent, with similar differences in substitution between surface and centre being observed. PolyHIPE(R) monolithic samples were brominated to an extent of 3.6 mmol g(-1) furthermore, this was uniform across the entire substrate. The differences in extent of each reaction are explained by consideration of such factors as the nature of the solvent, polarity of the reagents and compatibility between the reagents and the polymer matrix throughout the reactions., ROYAL SOC CHEMISTRY, May 1996, JOURNAL OF MATERIALS CHEMISTRY, 6 (5), 719 - 726, web_of_science

    Scientific journal

  • Spatial information on a polymer gel as studied by H-1 NMR imaging .3. Shrinkage by the application of an electric field to a composite polymer gel

    H Kurosu; T Shibuya; H Yasunaga; Ando, I

    H-1 NMR imaging patterns of a composite poly(methacrylic acid) (PMAA) gel being a double cylindrical rod, for which the swelling degrees of the inside and outside gels are different from each other, were measured under the application of an electric field. On the basis of these experimental results the shrinkage process was studied. It was found that the shrinkage process of the composite PMAA gel is different from the case of a homogenous cylindrical PMAA gel as reported previously [Macromolecules, 28, 4377 (1995)]. Details of the shrinkage process were discussed at the molecular level., SOC POLYMER SCIENCE JAPAN, 1996, POLYMER JOURNAL, 28 (1), 80 - 85, web_of_science

    Scientific journal

  • Structural and dynamical studies of C-13-labeled polyethylene adsorbed on the surface of silica gel by high-resolution solid-state C-13 NMR spectroscopy

    D Inoue; H Kurosu; Q Chen; Ando, I

    C-13 CP/MAS NMR spectra of 10% C-13-labeled polyethylene adsorbed on the surface of silica gel were measured by means of high-resolution solid-state C-13 NMR. From these experimental results, it was found that adsorbed polyethylene has immobile and mobile parts. In the immobile part, the polyethylene takes the trans conformation as the major conformation and gauche as the minor conformation, and in the mobile part fast transition between trans and gauche conformations occurs. Furthermore, in order to elucidate the dynamics of the polyethylene, C-13 spin-lattice relaxation times T-1 were measured. It was found that the molecular motion of the polyethylene in the mobile part is strongly restricted, compared with the noncrystalline component of polyethylene in bulk., VCH PUBLISHERS INC, Dec. 1995, ACTA POLYMERICA, 46 (6), 420 - 423, web_of_science

    Scientific journal

  • STRUCTURAL CHARACTERIZATION OF POLYACENIC POLYMERS IN THE SOLID-STATE BY HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

    H KUROSU; Y NAKAJIMA; ANDO, I

    The solid-state C-13 CP/MAS NMR spectra of undoped and iodine-doped polyacenic polymers with different electrical conductivity which were prepared by heating at high temperatures of 590 to 670 degrees C have been measured by means of solid-state high-resolution C-13 NMR. The C-13 Signal of the polyacenic polymer consists of four peaks. The four peaks obtained have been assigned to the structures of polyacenic polymer and a small amount of unreacted phenolformaldehyde resin. Further, the structure of polyacenic polymer in the solid state was discussed as related to the electrical conductivity., ELSEVIER SCIENCE BV, Aug. 1995, JOURNAL OF MOLECULAR STRUCTURE, 355 (1), 27 - 32, web_of_science

    Scientific journal

  • C-13 CPMAS NMR-STUDY OF THE STRUCTURE OF P-T-BUTYLCALIX[4]ARENE-ALKYLBENZENE CLATHRATES IN THE SOLID-STATE

    T YAMANOBE; NAKAMURA, I; K HIBINO; T KOMOTO; H KURUSU; ANDO, I; Y NAKAMOTO; S ISHIDA

    The NMR chemical shifts measured by the C-13 CPMAS method for clathrates of p-t-butylcalix[4]arenes including mobile alkylbenzenes in the solid state revealed that the alkyl groups of the guest molecules are located in the cavity of p-t-butylcalix[4]arene, depending on the size of the alkyl group. It was found that n-alkylbenzenes are easily incorporated into p-t-butylcalix[4]arene in the order of toluene > ethylbenzene greater than or equal to n-propylbenzene. For isopropylbenzene, the bulky isopropyl group prevents incorporation into the cavity of the host molecule., ELSEVIER SCIENCE BV, Aug. 1995, JOURNAL OF MOLECULAR STRUCTURE, 355 (1), 15 - 20, web_of_science

    Scientific journal

  • SPATIAL INFORMATION ON A POLYMER GEL AS STUDIED BY H-1-NMR IMAGING .2. SHRINKAGE BY THE APPLICATION OF AN ELECTRIC-FIELD TO A POLYMER GEL

    T SHIBUYA; H YASUNAGA; H KUROSU; ANDO, I

    H-1 NMR imaging patterns with information about the spatial distribution of H-1 spin density and H-1 spin-spin relaxation time T-2 of water molecules in a cross-linked poly(methacrylic acid) (PMAA) gel were measured, in order to clarify the translational behavior of water molecules in the gel under shrinkage processes by the application of an electric field. From the experimental result it was found that a cylindrical gel shrank to a wine-stopper-like shape at long elapsed time after the application of an electric field. On the positive electrode side, the H-1 spin densities were high and the mobilities were low, and on the negative electrode side, the H-1 spin densities were low and the mobilities high. Further, details of the shrinkage process were discussed at the molecular level., AMER CHEMICAL SOC, Jun. 1995, MACROMOLECULES, 28 (13), 4377 - 4382, web_of_science

    Scientific journal

  • STRUCTURAL CHARACTERIZATION OF POLYPYRROLE IN THE SOLID-STATE BY HIGH-RESOLUTION N-15 NMR-SPECTROSCOPY .2.

    H KUROSU; M KIKUCHI; ANDO, I

    The solid-state N-15 CP/MAS NMR spectra and N-15 spin-lattice relaxation times (T-1) of doped and dedoped N-15-labeled polypyrroles prepared by electrochemical polymerization, have been measured by means of high-resolution solid-state N-15 NMR. The N-15 Signal of polypyrrole consists of four peaks decomposed by line shape analysis. The four peaks obtained have been assigned to the various structures of polypyrrole. Further, the half-width of the N-15 NMR spectra of polypyrroles is discussed as related to the electrical conductivity. (C) 1995 John Wiley and Sons, Inc., JOHN WILEY & SONS INC, Apr. 1995, JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 33 (5), 769 - 775, web_of_science

    Scientific journal

  • CONFORMATION AND MOLECULAR-MOTION OF A POLY(L-GLUTAMATE) WITH LONG N-ALYL SIDE-CHAINS IN THE SOLID-STATE AND THE LIQUID-CRYSTALLINE STATE AS STUDIED BY HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY .2.

    E KATOH; H KUROSU; S KUROKI; ANDO, I

    C-13 CP/MAS and PST/MAS NMR experiments are carried out on poly(gamma-n-octadecyl L-glutamate) (POLG) over a wide range of temperatures from -40 to 230-degrees-C to elucidate dynamical and conformational features in the solid state and the liquid-crystalline state, in addition to the experimental findings reported previously. From these experimental results it was found that as the temperature is increased and the methylene carbons of the n-alkyl side-chains are away from the main-chain, the gauche fraction is increased but the magnitude of its temperature change is decreased. Furthermore, from the experimental results on the temperature dependence of the C-13 chemical shift of the main-chain carbonyl carbon, it was found that the main-chain takes the right-handed alpha-helix form in the temperature range from -40 to 230-degrees-C, and that as the temperature is increased, the amide hydrogen-bond length in the main-chain is increased slightly., ELSEVIER SCIENCE BV, Sep. 1994, JOURNAL OF MOLECULAR STRUCTURE, 326, 145 - 150, web_of_science

    Scientific journal

  • NITROGEN NMR OF SOME SULFUR DIIMIDE ANIONS AND CALCULATED (GIAO) NITROGEN SHIELDING CONSTANTS

    B WRACKMEYER; S GERSTMANN; M HERBERHOLD; GA WEBB; H KUROSU

    Sulphur diimide anions of the type [NSN](2-) (1), [RNSN](-) (1), [R = (1)Bu (3), SiMe(3) (4), (1)Bu(2)P (5)] were prepared with the counter ions [(1)Bu(4)N](+) or [(Me(2)N)(3)S](+) (for 1, 3, 4) and K+ (for 5) and studied in solution by N-14 NMR, and for assignment purposes by N-15 NMR (4). The experimentally determined N-14 chemical shifts (delta N) were compared with nitrogen shielding constants calculated by the gauge included atomic orbitals (GIAO) technique, and a linear relationship between sigma(N(calc)) and delta N was obtained. This correlation serves to support the Z configuration of the anions [RNSN](-), analogous to the isoelectronic N-sulphinylamines. On this basis, two N-14 resonance signals reported in the literature with uncertain assignment can be attributed to [HNSN](-) (2), and the previously assigned delta N values suggest that the anion [HNSNS](-) (6) adopts the Z/E configuration., JOHN WILEY & SONS LTD, Aug. 1994, MAGNETIC RESONANCE IN CHEMISTRY, 32 (8), 492 - 495, web_of_science

    Scientific journal

  • STRUCTURAL STUDY OF PEPTIDES CONTAINING L-ALANINE RESIDUES BY AB-INITIO CHEMICAL SHIELDING CALCULATION

    N ASAKAWA; H KUROSU; ANDO, I

    The correlation between the chemical shifts and the main-chain dihedral angles of peptides containing L-alanine residues are estimated by carrying out chemical shielding calculations using the coupled Hartree-Fock method with the gauge invariant atomic orbitals (GIAO-CHF). This aids understanding of the C-13 chemical shift behavior of the peptides and polypeptides., ELSEVIER SCIENCE BV, Jul. 1994, JOURNAL OF MOLECULAR STRUCTURE, 323, 279 - 285, web_of_science

    Scientific journal

  • AN NMR-STUDY OF STRUCTURE AND DYNAMICS OF POLY(FUMARATE)S IN THE SOLID-STATE (II)

    H KUROSU; K SUZUKI; ANDO, I; T OTSU

    C-13 spin-lattice relaxation times (T1c) and C-13 CP-MAS NMR spectra of poly(methyl tert-butyl fumarate) (PMETBF) and poly(isopropyl tert-butyl fumarate) (PIPTBF) were measured over a wide range of temperatures (-30 to 100-degrees-C). From these results, the molecular motion of the main chain and side chains of these polymers was elucidated, and the reorientation frequency of the main chain of PMETBF and PIPTBF was found to be below 67.8 MHz in this temperature range. Further, it was found that the mobilities for the meso-meso (mm) and meso-racemic (mr) triads of PIPTBF were almost the same below 85-degrees-C, but above 85-degrees-C the mobility for the mm triad was lower than that for the mr triad. However, there was no difference in the mobility between the mm and mr triads of PMETBF within the measured temperature range., ELSEVIER SCIENCE BV, May 1994, JOURNAL OF MOLECULAR STRUCTURE, 321 (3), 229 - 237, web_of_science

    Scientific journal

  • Rigid-Rod Polyesters with Flexible Side Chains Based on 1,4-Dialkyl Esters of Pyromellitic Acid and 4,4′-Biphenol. 5. High-Resolution 13C NMR Studies for Crystalline and Liquid Crystalline Layered Phases

    Masato Sone; Brian R. Harkness; Hiromichi Kurosu; Isao Ando; Junji Watanabe

    Rigid-rod aromatic B-Cn polyesters with long alkyl side chains, composed of 1,4-dialkyl esters of pyromellitic acid and 4,4′-biphenol, form two distinct types of crystalline phases, K1 and K2, depending on the length of alkyl side chain. These crystalline phases are characterized by a layered structure, in which the aromatic main chains are packed into a layer with the side chains crystallized in the space between the layers. The detailed structures for these two crystalline phases were studied by 13C solid-state NMR spectroscopy from which it was found that there are remarkable differences in the main-chain conformation and in the packing structure of the side chains. In the K1 crystal formed by the B-Cn polymers with shorter side chains, the aromatic main chain assumes a twisted conformation with the side chains packed into an orthorhombic lattice. In contrast, in the K2 crystal of the longer side-chain B-Cn polymers, the main chains assume a coplanar conformation with the side chains packed into a triclinic lattice. The NMR studies have also been extended to the two types of layered mesophases, LC-1 and LC-2, formed by these polymers. In these phases, the side chains are molten, with the main chains in the LC-1 and LC-2 phases assuming conformations similar to those in the K1 and K2 crystals, respectively. FPT-INDO calculations for the conformational energy have shown that the coplanar conformation in the K2 and LC-2 phases is strongly disfavored whereas the twisted conformation is stable. It is believed that the disfavored coplanar conformation observed in the K2 and LC-2 phases is forced by the layered segregation of the aromatic main chains and the long aliphatic side chains. © 1994, American Chemical Society. All rights reserved., 01 May 1994, Macromolecules, 27 (10), 2769 - 2777, doi;scopus;scopus_citedby

    Scientific journal

  • CONFORMATION AND MOLECULAR-MOTION OF POLY(L-GLUTAMATE) WITH LONG N-ALKYL SIDE-CHAINS IN THE SOLID-STATE AND THE LIQUID-CRYSTALLINE STATE AS STUDIED BY HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

    E KATOH; H KUROSU; ANDO, I

    C-13 CP-MAS NMR experiments are carried out for poly(gamma-n-octadecyl-L-glutamate) over a wide range of temperatures, in order to elucidate exact dynamic and conformational features in the solid state and the liquid crystalline state, as well as from the experimental findings reported previously by C-13 CP-MAS NMR and H-1 pulsed NMR methods. From these experimental results, it was found that at low temperatures n-alkyl side chains take an all-trans zigzag conformation, above 40-degrees-C they behave like liquid alkanes in a mobile state, and in the temperature range 0-20-degrees-C they are in a phase similar to the rotator phase of n-alkanes. The main chain takes on a right-handed alpha-helix conformation within the temperature range -40-230-degrees-C. Further, it was found that at temperatures above 40-degrees-C the polymer forms several liquid crystalline phases, in which the molecular motions of the polymer are different from each other., ELSEVIER SCIENCE BV, Mar. 1994, JOURNAL OF MOLECULAR STRUCTURE, 318, 123 - 131, web_of_science

    Scientific journal

  • A STRUCTURAL STUDY OF PEPTIDES AND PROTEINS CONTAINING L-ALANINE RESIDUES BY C-13 NMR-SPECTROSCOPY COMBINED WITH AB-INITIO CHEMICAL-SHIFT CALCULATIONS

    N ASAKAWA; H KUROSU; ANDO, I; A SHOJI; T OZAKI

    From the observation of solid-state C-13 NMR chemical shifts of L-alanine residues which are contained in some peptides, and the C-13 chemical shift calculations employing the coupled-Hartree Fock method with gauge-invariant-atomic-orbital, it was found that the C-13 chemical shift of the C(beta)-carbon in the L-alanine residue is related to the main-chain dihedral angles, phi, psi, but that of the C(alpha)-carbon is affected not only by dihedral angles but also by hydrogen-bonding structure. These results were successfully applied to the structural study of proteins in solution, ribonuclease H from Escherichia coli and basic pancreatic trypsin inhibitor., ELSEVIER SCIENCE BV, Jan. 1994, JOURNAL OF MOLECULAR STRUCTURE, 317 (1-2), 119 - 129, web_of_science

    Scientific journal

  • SIDE-CHAIN CONFORMATION OF POLY(L-PROLINE) FORM-II IN THE CRYSTALLINE STATE AS STUDIED BY HIGH-RESOLUTION SOLID-STATE C-13 NMR-SPECTROSCOPY

    M SONE; H YOSHIMIZU; H KUROSU; ANDO, I

    High-resolution C-13 NMR spectra of poly(L-proline) form II in the solid state were measured using the CP MAS and PST/MAS techniques over a wide range of temperatures. From these results. it was found that the pyrrolidine ring in the form II takes two types of conformations, and the mobilities of the pyrrolidine rings in the two types of conformations are different from each other. The behaviour of the main-chain and side-chain conformations of poly(L-proline) was elucidated through the observed C-13 NMR chemical shifts and the calculations of the C-13 NMR shielding constant and total energy of these polypeptides within the tight-binding INDO/S sum-over-states framework., ELSEVIER SCIENCE BV, Jan. 1994, JOURNAL OF MOLECULAR STRUCTURE, 317 (1-2), 111 - 118, web_of_science

    Scientific journal

  • Ring puckering of the pyrrolidine ring of poly (l-proline) form I as studied by variable-temperature high-resolution 13C NMR spectroscopy

    Masato Sone; Hiroaki Yoshimizu; Hiromichi Kurosu; Isao Ando

    10 Dec. 1993, Journal of Molecular Structure, 301 (C), 227 - 230, doi;scopus;scopus_citedby

    Scientific journal

  • AN NMR-STUDY OF STRUCTURE AND DYNAMICS OF POLY(FUMARATE)S IN THE SOLID-STATE

    H KUROSU; T YAMADA; ANDO, I; K SATO; T OTSU

    C-13 cross polarization/magic angle spinning (CP/MAS) NMR spectra and partially-relaxed C-13 NMR spectra of poly(diisopropyl fumarate) (PDiPF) and poly(dicyclohexyl fumarate) (PDCHF) in the solid state were measured over a wide range of temperatures. On the basis of these experiments, C-13 spin-lattice relaxation times (T1C) for the polymers were determined as a function of temperature. From these results, the molecular motion of the main chain and side chains of the polymers was clearly elucidated. In addition, H-1 spin-lattice relaxation times (T1H) and H-1 spin-lattice relaxation times in the rotating frame (T1rho(H)) of the polymers were measured by H-1 pulse NMR over a wide range of temperatures. From these results, dynamics of the main chain and side chains of these polymers was elucidated. The reorientation frequency of the main chain of PDiPF is about 43 kHz at 120-degrees-C, while that of PDCHF at 120-degrees-C is less than this. These pulse NMR results do not conflict with the CP/MAS NMR results., ELSEVIER SCIENCE BV, Dec. 1993, JOURNAL OF MOLECULAR STRUCTURE, 300, 303 - 311, web_of_science

    Scientific journal

  • THEORETICAL-STUDY OF THE GAMMA-GAUCHE EFFECT FOR AN N-PARAFFIN BY USING AN ABINITIO GIAO-CHF PROCEDURE

    H KUROSU; ANDO, I; GA WEBB

    Ab initio C-13 nuclear shielding calculations of the gamma-gauche effect for an n-paraffin using the GIAO-CHF procedure are reported. The geometrical parameters used are optimized for each dihedral angle. The dihedral angle dependences of shielding constant calculations are carried out and the gamma-gauche effect on n-octane is discussed., JOHN WILEY & SONS LTD, Apr. 1993, MAGNETIC RESONANCE IN CHEMISTRY, 31 (4), 399 - 402, web_of_science

    Scientific journal

  • STRUCTURE AND MOLECULAR-MOTION OF POLY(ETHYLENE OXIDE) IN THE SOLID-STATE AS STUDIED BY QUANTUM-CHEMISTRY AND SOLID-STATE NMR

    H KUROSU; ANDO, I

    ELSEVIER SCIENCE PUBL B V, 1993, COMPUTER AIDED INNOVATION OF NEW MATERIALS II, PTS 1 AND 2, 1401 - 1404, web_of_science

    International conference proceedings

  • A QUANTUM-CHEMICAL STUDY OF PVA CRYSTAL-STRUCTURE

    T ISHII; S AMIYA; H KUROSU; ANDO, I

    ELSEVIER SCIENCE PUBL B V, 1993, COMPUTER AIDED INNOVATION OF NEW MATERIALS II, PTS 1 AND 2, 1405 - 1408, web_of_science

    International conference proceedings

  • SPATIAL INFORMATION ON A POLYMER GEL AS STUDIED BY H-1-NMR IMAGING .1. IMAGE-ANALYSIS OF STRESS-STRAIN

    H YASUNAGA; H KUROSU; ANDO, I

    H-1 NMR imaging experiments were carried out to obtain spatial information on the propagation of the strain induced by stress in a cross-linked poly(methacrylic acid) (PMAA)/water gel. The H-1 spin density and spin-spin relaxation time enhanced NMR imaging patterns for water contained in a PMAA gel under stress were successfully observed. From these results it was found that the spatial distributions of the H-1 spin density and the molecular motion of water molecules in the gel are changed by altering the strength of stress and that the H-1 spin density and the molecular motion of water in the compressed region become lower and slower, respectively, compared with those in the surrounding uncompressed region., AMER CHEMICAL SOC, Nov. 1992, MACROMOLECULES, 25 (24), 6505 - 6509, web_of_science

    Scientific journal

  • ABINITIO C-13 NUCLEAR SHIELDING CALCULATIONS FOR SOME HYDROCARBONS USING THE GIAO PROCEDURE

    H KUROSU; GA WEBB; ANDO, I

    The results of some ab initio GIAO-CHF C-13 shielding calculations for some hydrocarbons, performed with several basis sets, are reported and compared with experimental data. Optimized and experimental molecular geometries have been used in these calculations. The effect of the choice of basis set and geometric parameters on the calculated shieldings are discussed., JOHN WILEY & SONS LTD, Nov. 1992, MAGNETIC RESONANCE IN CHEMISTRY, 30 (11), 1122 - 1124, web_of_science

    Scientific journal

  • CONFORMATIONAL BEHAVIOR OF POLY(BETA-BENZYL L-ASPARTATE) IN THE SOLID-STATE AS STUDIED BY VARIABLE-TEMPERATURE C-13 CROSS-POLARIZATION MAGIC ANGLE SPINNING NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

    T AKIEDA; H MIMURA; S KUROKI; H KUROSU; ANDO, I

    Carbon-13 cross-polarization/magic angle spinning nuclear magnetic resonance experiments are carried out for poly(beta-benzyl L-aspartate)(PBLA) over a wide range of temperatures, in order to elucidate the stability of the conformation in the solid state. From these experimental results, we obtained the following results on the thermal stability of the main chain. The main chain of PBLA takes on a right-handed a-helical conformation (alpha(R)-helix) within the temperature range from room temperature (23-degrees-C) to 117-degrees-C, and the main-chain conformation predominantly changes at about 128-degrees-C from an alpha(R)-helix form to a left-handed omega-helical form (omega(L)-helix), although minor transition to the beta-sheet form occurs. In the temperature range from 128 to 139-degrees-C a mixture of three types of conformations, the alpha(R)-helix, omega(L)-helix, and beta-sheet forms, coexist. At 150-degrees-C the alpha(R)-helix form completely transforms to the omega(L)-helix or beta-sheet form, and in the temperature range from 150 to 161-degrees-C a mixture of both the forms exists. At 173-degrees-C the maim-chain conformation completely becomes the beta-sheet conformation., AMER CHEMICAL SOC, Oct. 1992, MACROMOLECULES, 25 (21), 5794 - 5797, web_of_science

    Scientific journal

  • STRUCTURE AND C-13 NMR CHEMICAL-SHIFT BEHAVIOR OF N-ALKANE CHAINS IN THE ROTATOR PHASE AS STUDIED BY THE TIGHT-BINDING MO THEORY WITHIN THE INDO/S FRAMEWORK

    S ISHIKAWA; H KUROSU; ANDO, I

    Tight-binding MO calculations on the C-13 NMR chemical shifts for n-alkane chains in the rotator phase have been carried out within the INDO/S sum-over-states framework, taking into account the interchain interactions. The calculations show that the interchain interactions play an important role in determining chemical shift behaviour in the rotator phase. The relationship between the structure and C-13 NMR chemical shift was further clarified through the understanding of the electronic state of the n-alkane chains in the rotator phase., ELSEVIER SCIENCE BV, Oct. 1992, JOURNAL OF MOLECULAR STRUCTURE, 273, 233 - 241, web_of_science

    Scientific journal

  • Anomalous temperature dependence of low-energy-electron transmission spectra of thin films of tetrakis(nonylth10)-tetrathiafulvalene (TTC9-TTF)

    N. Ueno; K. Sugita; H. Kurosu; K. Seki; G. Saito; H. Inokuchi

    Temperature dependence of low-energy-electron transmission spectra was measured for thin films of a molecular fastener, tetrakis(nonylthio)tetrathiafulvalene. 10 spectral features, which can be ascribed to the structure of the conduction bands, were observed in the energy region of incident electron of 0 — 15 eV. They showed a large temperature dependence of the energy position as well as of the sharpness and the intensity. The energy positions shifted ∼0.6 eV to high-energy side by cooling from room temperature to −124°C. Such a large energy shift was not observed for other thin films consisting of Iong-alkyl molecules, and is considered as a result of the molecular fastener effects. © 1992, Taylor & Francis Group, LLC. All rights reserved., 01 Jun. 1992, Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 218 (1), 171 - 176, doi

    Scientific journal

  • DYNAMIC STUDY OF THE NONCRYSTALLINE PHASE OF C-13-LABELED POLYETHYLENE BY VARIABLE-TEMPERATURE C-13 CP MAS NMR-SPECTROSCOPY

    Q CHEN; T YAMADA; H KUROSU; ANDO, I; T SHIONO; Y DOI

    The C-13 spin-lattice relaxation times T1 of C-13-labeled polyethylene crystallized under different conditions were measured at temperatures from -120 to 44-degrees-C by variable-temperature solid-state high-resolution C-13 nuclear magnetic resonance (NMR) spectroscopy, in order to determine accurately the dynamics of the noncrystalline region of the polymer. From these results, it was found that the T1 minimum for the CH2 carbons in the noncrystalline region of solution-crystallized polyethylene with high crystallinity appears at higher temperature by about 20-degrees-C than that of melt-quenched polyethylene with low crystallinity. This means that the molecular motion of the CH2 carbons in the noncrystalline regions is more constrained at a given temperature in the material of higher crystallinity. Furthermore, dynamics of the noncrystalline region is discussed in terms of the C-13 dipolar dephasing times., JOHN WILEY & SONS INC, May 1992, JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 30 (6), 591 - 601, web_of_science

    Scientific journal

  • STRUCTURAL CHARACTERIZATION OF POLYPYRROLE IN THE SOLID-STATE BY HIGH-RESOLUTION N-15 NMR-SPECTROSCOPY COMBINED WITH QUANTUM-CHEMISTRY

    M KIKUCHI; H KUROSU; ANDO, I

    The N-15 CP/MAS NMR spectra of doped and undoped N-15-labeled polypyrroles in the solid state, prepared by electrochemical polymerization, were measured by means of high-resolution solid-state NMR and related to electrical conductivity. From these results, it was found that the N-15 signal of polypyrrole consists of at least four peaks which were decomposed by computer-fitting. In order to obtain systematic information on the structure and electronic structure, a quantum chemical calculation was carried out to assist in analyzing the four N-15 peaks., ELSEVIER SCIENCE BV, May 1992, JOURNAL OF MOLECULAR STRUCTURE, 269 (1-2), 183 - 195, web_of_science

    Scientific journal

  • HYDROGEN-BONDING EFFECT ON C-13 NMR CHEMICAL-SHIFTS OF L-ALANINE RESIDUE CARBONYL CARBONS OF PEPTIDES IN THE SOLID-STATE

    N ASAKAWA; S KUROKI; H KUROSU; ANDO, I; A SHOJI; T OZAKI

    In order to investigate the relationship between hydrogen-bond length and C-13 NMR chemical shifts of L-alanine carbonyl carbons in peptides in the solid state, C-13 CP-MAS NMR spectra were measured for a series of peptides containing L-alanine residues, for which the crystal structures were already determined by X-ray diffractions. From the results of the observed C-13 chemical shifts, it was found that the isotropic C-13 chemical shifts (delta(iso)) of L-alanine residues move linearly downfield with a decrease of hydrogen-bond length (R(N...O)) as expressed by delta(iso) = 237.5-21.7 R(N...0) ppm. Such a downfield shift of delta(iso) predominantly arises from the large downfield shift of delta-22, one of the chemical shift tensor components (delta-11, delta-22, and delta-33) with decreasing R(N...0). Delta-11 moves somewhat upfield with R(N...0) and delta-33 is not sensitive to a change of R(N...0). The quantum-chemical calculation of the C-13 shielding constant for the model compound was carried out by the FPT-INDO method, and the hydrogen-bonding effect on the C-13 chemical shift in the ]C = O...H-N[ type hydrogen bond and the nature of the hydrogen bond are discussed., AMER CHEMICAL SOC, Apr. 1992, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 114 (9), 3261 - 3265, web_of_science

    Scientific journal

  • PHASE-TRANSITION IN CYCLOHEXATRIACONTANE AS STUDIED BY VARIABLE-TEMPERATURE C-13 CP MAS NMR-SPECTROSCOPY

    Q CHEN; H KUROSU; ANDO, I; H SATO

    Variable-temperature C-13 CP/MAS spectra of cyclohexatriacontane (C36H72) in the solid state over a wide range of temperatures were measured, in order to study the phase transition and conformational change of the molecule with temperature. The signals associated with the constrained gauche conformations clearly appear in the spectra at temperatures below 0-degrees-C. A new peak at about 30.3 ppm is observed in the C-13 CP/MAS spectrum at 0-degrees-C. The relative intensity of this peak increases gradually and the other signals become broad with an increase in temperature. This indicates the existence of the "pseudorotator phase" in which C36H72 is undergoing fast conformational interconversion before the melting transition., ELSEVIER SCIENCE BV, Jan. 1992, JOURNAL OF MOLECULAR STRUCTURE, 265 (1-2), 153 - 161, web_of_science

    Scientific journal

  • PHASE-TRANSITION IN CYCLOHEXATRIACONTANE AS STUDIED BY VARIABLE-TEMPERATURE C-13 CP MAS NMR-SPECTROSCOPY

    Q CHEN; H KUROSU; ANDO, I; H SATO

    Variable-temperature C-13 CP/MAS spectra of cyclohexatriacontane (C36H72) in the solid state over a wide range of temperatures were measured, in order to study the phase transition and conformational change of the molecule with temperature. The signals associated with the constrained gauche conformations clearly appear in the spectra at temperatures below 0-degrees-C. A new peak at about 30.3 ppm is observed in the C-13 CP/MAS spectrum at 0-degrees-C. The relative intensity of this peak increases gradually and the other signals become broad with an increase in temperature. This indicates the existence of the "pseudorotator phase" in which C36H72 is undergoing fast conformational interconversion before the melting transition., ELSEVIER SCIENCE BV, Jan. 1992, JOURNAL OF MOLECULAR STRUCTURE, 265 (1-2), 153 - 161, web_of_science

    Scientific journal

  • STRUCTURAL CHARACTERIZATION OF SOLUTION-CRYSTALLIZED C-13-LABELED POLYETHYLENE OVER A WIDE-RANGE OF TEMPERATURES BY MEANS OF HIGH-RESOLUTION C-13-NMR SPECTROSCOPY

    Q CHEN; T YAMADA; H KUROSU; ANDO, I; T SHIONO; Y DOI

    C-13 CP/MAS spectra of C-13-labeled solution crystallized polyethylene at temperatures from -120 to 144-degrees-C are measured, in order to study changes of structure and molecular motion of the polymer with temperature variation. From these results, it was found that the non-crystalline C-13 signal monotonically shifts downfield with a decrease of temperature, whereas the crystalline C-13 signal does not change obviously with temperature. The maximum of the non-crystalline peak width appears at -30-degrees-C and that of the crystalline peak width appears at 110.4-degrees-C. The appearance of the maximum of the crystalline peak width is considered to correlate with the alpha-transition. Another component besides the crystalline and non-crystalline components is found between 88 and 132.8-degrees-C, and is attributed to the interface and defects created in the heating process., ELSEVIER SCIENCE BV, Dec. 1991, JOURNAL OF MOLECULAR STRUCTURE, 263, 319 - 327, web_of_science

    Scientific journal

  • STRUCTURAL STUDIES OF N-ALKANES BY VARIABLE-TEMPERATURE SOLID-STATE HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

    S ISHIKAWA; H KUROSU; ANDO, I

    High-resolution C-13 NMR spectra of some n-alkanes (n-C19H40, n-C24H50, n-C32H66 and n-C44H90) in the solid state have been measured by means of variable-temperature, solid-state, high-resolution C-13 NMR spectroscopy as a function of temperature, in order to clarify the structural change over a wide range of temperatures. From these results, it was found that the C-13 chemical shift value of the internal CH2 carbons in n-CH24H50 moves from 34.2 to 33.3 ppm in going from the triclinic form to the rotator phase, and the C-13 chemical shift of the internal CH2 carbons of n-C19H40 and n-C32H66 moves from 32.8(32.9) to 33.3 ppm in going from the orthorhombic form to the rotator phase. This shows that the C-13 chemical shift values of n-alkanes in the rotator phase are the same irrespective of their chain length. Further, it was found that the structure of the chain-end parts in the intermediate phase and the rotator phase of longer n-alkanes is similar to that in the noncrystalline phase in which fast transition between trans and gauche isomers occurs., ELSEVIER SCIENCE BV, Aug. 1991, JOURNAL OF MOLECULAR STRUCTURE, 248 (3-4), 361 - 372, web_of_science

    Scientific journal

  • INTERCHAIN INTERACTION OF C-13 NMR CHEMICAL-SHIFT AND ELECTRONIC-STRUCTURE OF POLYPEPTIDE-CHAINS IN THE SOLID-STATE AS STUDIED BY TIGHT-BINDING MO THEORY - POLY(L-ALANINE) WITH THE RIGHT-HANDED AND LEFT-HANDED ALPHA-HELIX FORMS

    H KUROSU; ANDO, I

    Tight-binding MO-INDO/S sum-over-states theory has been employed to calculate the C-13 NMR chemical shifts and electronic structures for seven right- and left-handed alpha-poly (L-alanine) chain models taking into account interchain interactions. The calculations show that the interchain interactions play an important role in determining the chemical shift behavior. Further, the effects of interchain distance on the chemical shift and electronic structure are discussed., ELSEVIER SCIENCE BV, Jun. 1991, JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, 77, 231 - 242, web_of_science

    Scientific journal

  • SIDE-CHAIN STRUCTURE OF POLY(METHACRYLIC ACID) AND ITS ZINC SALTS IN THE SOLID-STATE AS STUDIED BY HIGH-RESOLUTION SOLID-STATE C-13 NMR-SPECTROSCOPY

    M ASADA; N ASADA; A TOYODA; ANDO, I; H KUROSU

    High-resolution solid-state C-13 CP/MAS NMR experiments for isotactic and syndiotactic poly(methacrylic acid)s (PMAA) have been carried out at room temperature, and further those for the zinc salts have been carried out at temperatures from room temperature to about 170-degrees-C. The carboxyl carbon resonance of PMAA was separated into four peaks, three of which move about 3, 6 and 9 ppm downfield, respectively, as compared with the corresponding chemical shift values in solution. The chemical shift value of the remaining peak agrees with that in solution. Based on these experimental results and quantum chemical calculations on the C-13 NMR chemical shift, the observed large downfield shift in the solid state is ascribed to the formation of intermolecular or intramolecular hydrogen bonds. Both the C-13 chemical shift values and the relative peak intensities of the carboxyl carbon in PMAA-zinc salt were almost independent of temperature at temperatures from room temperature to 170-degrees-C. This suggests that the interaction between carboxyl group and zinc does not change within its temperature range., ELSEVIER SCIENCE BV, Apr. 1991, JOURNAL OF MOLECULAR STRUCTURE, 244, 237 - 248, web_of_science

    Scientific journal

  • STRUCTURAL CHARACTERIZATION OF POLYALLENE IN THE SOLID-STATE AS STUDIED BY VARIABLE-TEMPERATURE HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

    KH MIN; H KUROSU; ANDO, I; T YAMAMOTO; T KANBARA

    High-resolution C-13 NMR spectra of polyallenes in the solid state were measured over the temperature range from room temperature to 100-degrees-C by means of the variable-temperature cross polarization/magic angle spinning NMR and pulse saturation transfer/magic angle spinning NMR techniques. It was shown that the C-13 resonance lines of the noncrystalline, orthorhombic, monoclinic, and paracrystalline forms are chemically shifted from one another. On the basis of these peak assignments, the structural change was studied over the course of the temperature change., AMER CHEMICAL SOC, Apr. 1991, MACROMOLECULES, 24 (8), 2011 - 2014, web_of_science

    Scientific journal

  • STRUCTURE AND MOLECULAR-MOTION OF POLY(ETHYLENE OXIDE) IN THE SOLID-STATE AS STUDIED BY VARIABLE-TEMPERATURE HIGH-RESOLUTION SOLID-STATE C-13 NMR

    H KUROSU; ANDO, I

    ELSEVIER SCIENCE BV, Oct. 1990, JOURNAL OF MOLECULAR STRUCTURE, 239, 149 - 159, web_of_science

    Scientific journal

  • SIDE-CHAIN CONFORMATION AND C-13-NMR CHEMICAL-SHIFT OF POLY(L-PHENYLALANINE) AND OLIGOPEPTIDES CONTAINING L-PHENYLALANINE AND TYROSINE RESIDUES IN THE SOLID-STATE

    H MIYAMOTO; T KOMOTO; H KUROSU; ANDO, I; T OZAKI; A SHOJI

    ELSEVIER SCIENCE BV, Apr. 1990, JOURNAL OF MOLECULAR STRUCTURE, 220, 251 - 260, web_of_science

    Scientific journal

  • C-13 NMR CHEMICAL-SHIFT AND CRYSTAL-STRUCTURE OF POLYETHYLENE CHAINS IN THE SOLID-STATE AS STUDIED BY TIGHT-BINDING THEORY WITHIN THE INDO-S FRAMEWORK

    H KUROSU; ANDO, I; T YAMANOBE

    ELSEVIER SCIENCE BV, Nov. 1989, JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, 60, 239 - 247, web_of_science

    Scientific journal

  • 13C NMR chemical shift and Crystal Structure of Polyethylene chains in the solid state as studied by Tight-Binding theory within the INDD/S framework

    YAMANOBE TAKESHI; Isao?Ando; Hiromichi?Kurosu

    NMR?chemical?shift?of?polyethylene?is?calculated?by?tight?binding?theory., 1989, J.Mol.Struct(THEOCHEM), 201

  • EFFECT OF INTERCHAIN INTERACTIONS ON C-13 NUCLEAR MAGNETIC-RESONANCE CHEMICAL-SHIFTS AND ELECTRONIC-STRUCTURES OF POLYACETYLENE IN THE SOLID-STATE AS STUDIED BY TIGHT-BINDING MOLECULAR-ORBITAL THEORY

    T ISHII; H KUROSU; T YAMANOBE; ANDO, I

    AMER INST PHYSICS, Dec. 1988, JOURNAL OF CHEMICAL PHYSICS, 89 (12), 7315 - 7319, web_of_science

    Scientific journal

  • C-13 NMR CHEMICAL-SHIFT AND CRYSTAL-STRUCTURE OF POLYOXYMETHYLENE IN THE SOLID-STATE

    H KUROSU; T KOMOTO; ANDO, I

    ELSEVIER SCIENCE BV, May 1988, JOURNAL OF MOLECULAR STRUCTURE, 176, 279 - 283, web_of_science

    Scientific journal

  • Interchain effect of 13C Nuclear Magnetic Reconance Chemical Shift and Electronic Structure of Poly oxymethylene chains in the Solid State

    KUROSU Hiromichi; H.Kurosu; T.Yamanobe; I.Ando

    1988, J. Chem. Phys., 89, 5216-5223

  • Effect of Interchain Interactions on 13C NMR Chemical Shifts and Electronic Structure of Polyasetylene in the solid state as Studied by Tight-Binding MO Theory

    KUROSU Hiromichi; T.Ishii; H.Kurosu; T.Yamanobe; I.Ando

    1988, J. Chem. Phys., 89, 7315-7319

  • C-13 NMR CHEMICAL-SHIFT AND ELECTRONIC-STRUCTURE OF POLYOXYMETHYLENE IN THE SOLID-STATE

    H KUROSU; T YAMANOBE; T KOMOTO; ANDO, I

    ELSEVIER SCIENCE BV, Sep. 1987, CHEMICAL PHYSICS, 116 (3), 391 - 398, web_of_science

    Scientific journal

  • The influence of thermal treatments on the secondary structure of silk fibroin scaffolds and their interaction with fibroblasts

    Tomoko Hashimoto; Yuka Nakamura; Yasushi Tamada; Hiromichi Kurosu; Tsunenori Kameda

    Background Recently, silk fibroin-based biomaterials have received attention for application in tissue engineering and drug delivery systems. The usefulness of heat sterilization methods for silk fibroin-based biomaterials was investigated in this study as all biomaterials are required to undergo a sterilization process when they are used in medical devices. Methods The influence of wet and dry heating on the properties of fibroin molecules in silk fibroin sponges was investigated by measurements of solid-state 13C cross-polarization/magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analyses, strength tests, and cell proliferation/migration assays. Results 13C CP/MAS NMR spectra of wet-heated sponges revealed no changes in the molecular structure below 50 °C. However, above 60 °C, the crystalline structure of the silk proteins transitioned from silk I to silk II; the silk II:silk I ratio increased with temperature. In contrast, dry heating (below 190 °C for up to 180 min) induced no structural changes in the fibroin molecules. These results indicate that, although autoclave sterilization (121 °C for 20 min) induces structural changes in silk fibroin sponges, no such changes are observed with the dry-heat sterilization (180 °C for 30 min). Sterilized sponges with a silk I structure can be obtained using dry-heat method during sterilization. Moreover, the structural differences between the wet- and dry-heated silk fibroin sponges did not influence their interaction with fibroblasts. Discussion This study indicates that both autoclaving and dry heating are acceptable sterilization methods for silk fibroin-based sponges as the scaffold. In particular, dry heating maintains the stability of the secondary structure of the sterilized silk fibroin-based biomaterials. , PeerJ, 01 Sep. 2020, PeerJ Materials Science, 2, e8 - e8, doi;url;url;url

    Scientific journal

MISC

  • Changes in the properties and protein structure of silk fibroin molecules in autoclaved fabrics

    Tomoko Hashimoto; Yuki Taniguchi; Tsunenori Kameda; Yasushi Tamada; Hiromichi Kurosu

    The influence of autoclaving on the properties of silk fibroin fabrics (SF(fab)s) was evaluated. High-performance liquid chromatography revealed that the molecular weight (Mw) of the fibroin molecule in SFfabs decreased as the treatment temperature and time increased, which suggests that the fibroin molecule in the fabrics was thermal degraded. Additionally, differential scanning calorimetry experiments revealed a shift of the endothermic peak to higher temperature with increasing treatment temperature and time, which indicates an improvement in the thermal stability of the fibroin molecule in the autoclaved fabrics. Furthermore, C-13 cross-polarization/magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR) analysis revealed that the intensity ratios for the beta-sheet and random-coil peaks fluctuated during autoclaving. The NMR analysis also revealed the presence of an unknown structure in the autoclaved SF(fab)s under certain conditions. The changes in the Mws and degradation temperatures for the autoclaved SF(fab)s are assumed to be induced by the structural changes observed via NMR. Consequently, autoclaving is considered to be an effective technique for modifying the secondary structure and properties of SF(fab)s with high beta-sheet contents using only water and heat without added reagents. (C) 2014 Elsevier Ltd. All rights reserved., ELSEVIER SCI LTD, Feb. 2015, POLYMER DEGRADATION AND STABILITY, 112, 20 - 26, doi;web_of_science

  • Synthetic macromolecules

    Hiromichi Kurosu; Takeshi Yamanobe

    In this chapter, the papers devoted to NMR application to study synthetic polymers over a period from June 2011 through May 2012 have been reviewed. It includes analysis of primary structure of polymers such as tacticity, regioregularity, end group, sequence distribution (section 2), application of imaging, diffusion and solidstate NMR techniques to characterize the synthetic macromolecules (sections 3 and 4). Finally in section 5, papers devoted to dynamics and polymer blend of the synthetic macromolecules have been surveyed. © The Royal Society of Chemistry 2013., 2013, Nuclear Magnetic Resonance, 42, 420 - 449, doi

    Book review

  • Synthetic macromolecules

    Hiromichi Kurosu; Takeshi Yamanobe

    2011, Nuclear Magnetic Resonance, 40, 391 - 431, doi

    Book review

  • Precise structural analysis of alpha-helical polypeptide by quantum-chemical calculation related to reciprocal side-chain combination of two L-phenylalanine residues

    Subaru Niimura; Hiromichi Kurosu; Akira Shoji

    To clarify the positive role of side-chain conformation in the stability of protein secondary structure (main-chain conformation), we successfully calculated the optimization structure of a series of well-defined alpha-helical octadecapeptides composed of two L-phenylalanine (Phe) and 16 L-alanine (Ala) residues, based on the molecular orbital calculation with density functional theory (DFT/B3LYP/6-31G(d)). From the total energy calculation and the precise secondary structural analysis, we found that the conformational stability of the alpha-helix is closely related to the reciprocal side-chain combinations (such as positional relation and side-chain conformation) of two Phe residues in this system. Furthermore, we demonstrated that the H-1, C-13, N-15 and O-17 isotropic chemical shifts of each Phe residue depend on the respective side-chain conformations of the Phe residue. (C) 2010 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Apr. 2010, JOURNAL OF MOLECULAR STRUCTURE, 970 (1-3), 96 - 100, doi;web_of_science

  • Conformational analysis of alpha-helical polypeptide included L-proline residue by high-resolution solid-state NMR measurement and quantum chemical calculation

    Hiroyuki Souma; Akira Shoji; Hiromichi Kurosu

    We challenged the problem about the stabilization mechanism of an alpha-helix formation for polypeptides containing L-proline (Pro) residue. We computed the optimized structure of alpha-helical poly(L-alanine) molecules including a Pro residue, H-(Ala)(8)-Pro-(Ala)(9)-OH, based on the molecular orbital calculation with density functional theory, B3LYP/6-31G(d) and the C-13 and N-15 chemical shift values based on the GIAO-CHF method with B3LYP/6-311G(d,p), respectively. It was found that two kinds of optimized structures, 'Bent structure' and 'Included alpha-helix structure', were preferred structures in H-(Ala)(8)-Pro-(Ala)(9)-OH. In addition, based on the precise C-13 and N-15 chemical shift data of the simple model, we successfully analyzed the secondary structure of well-defined synthetic polypeptide H-(Phe-Leu-Ala)(3)-Phe(C)-Pro-Ala(N)-(Phe-Leu-Ala)(2)-OH (FLA-11P), the secondary structure of which was proven to the 'Included alpha-helix structure'. (C) 2008 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Oct. 2008, JOURNAL OF MOLECULAR STRUCTURE, 889 (1-3), 237 - 243, doi;web_of_science

  • Solid-state NMR studies on semicrystalline polymers

    Qun Chen; Hiromichi Kurosu

    In this review, we summarize recent works on semicrystalline polymers as studied by solid-state NMR, with the emphasis on demonstrating the potential of NMR techniques in characterizing the phase structures, chain conformation, intermolecular interactions as well as chain dynamics of semicrystalline polymers., ELSEVIER ACADEMIC PRESS INC, 2007, ANNUAL REPORTS ON NMR SPECTROSCOPY, VOL 61, 61, 247 - 281, doi;web_of_science

  • Synthetic Macromolecules

    KUROSU Hiromichi; Takeshi Yamanobe

    2006, Specialist Periodical Reports Nuclear Magnetic Resonance, 35, 389-418

  • Synthetic Macromolecules

    KUROSU Hiromichi; H.Kurosu; T.Yamanobe

    2005, Specialist Periodical Reports Nuclear Magnetic Resonance, 34, 415-470

  • Structural studies of polymer blends by solid-state NMR

    H Kurosu; Q Chen

    In this review, we introduce recent research works on polymer blends as studied by solid state NMR and focus on the miscibility and phase separation of polymer blends that are responsible for the improvement in their physical properties., ACADEMIC PRESS LTD, 2004, ADVANCES IN SOLID STATE NMR STUDIES OF MATERIALS AND POLYMERS: A SPECIAL VOLUME DEDICATED TO ISAO ANDO, 52, 167 - 200, doi;web_of_science

    Book review

  • Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe

    2002, Specialist Periodical Reports Nuclear Magnetic Resonance, 31, 353-387

  • NMR chemical shift calculations and structural characterizations of polymers

    Ando, I; S Kuroki; H Kurosu; T Yamanobe

    PERGAMON-ELSEVIER SCIENCE LTD, Aug. 2001, PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY, 39 (2), 79 - 133, web_of_science

    Book review

  • Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe

    2001, Specialist Periodical Reports Nuclear Magnetic Resonance, 30, 377-411

  • NMR Chemical Shifts and Structures of Polymers

    YAMANOBE TAKESHI; Isao Ando; Shigeki Kuroki; Hiromichi Kurosu

    2000, Report on Progress in Polymer Physics in Japan, Vol.43 467

  • NMR spectroscopy in polymer science

    KUROSU Hiromichi; I.Ando; M.Kobayashi; M.Kanekiyo; S.Kuroki; S.Ando; S.Matsukawa; H.Kurosu; H.Yasunaga; S.Amiya

    2000, Exp. Methods Polym. Sci., 261-493

  • Oxygen-17 NMR chemical shifts in peptides and hydrogen-bonding structures

    S Kuroki; H Kurosu; S Ando; Ando, I

    AMER CHEMICAL SOC, Aug. 1998, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 216, U724 - U724, web_of_science

    Summary international conference

  • Conformational study of the L-alanine residue in polypeptides by ab initio C-13 NMR shielding calculation.

    H Kurosu; K Fukuyama; Ando, I

    AMER CHEMICAL SOC, Aug. 1998, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 216, U724 - U724, web_of_science

    Summary international conference

  • Modeling chemical shifts in polymers and amorphous matter

    Ando, I; H Kurosu; M Uchida; T Yamanobe

    AMER CHEMICAL SOC, Aug. 1998, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 216, U701 - U701, web_of_science

    Summary international conference

  • Synthetic Macromolecules

    KUROSU Hiromichi; H.Kurosu; T.Yamanobe

    1998, Specialist Periodical Reports Nuclear Magnetic Resonance, 127, 337-369

  • Synthetic Macromolecules

    KUROSU Hiromichi; H.Kurosu; T.Yamanobe

    1998, Specialist Periodical Reports Nuclear Magnetic Resonance, 27, 337-369

  • Structures and Dynamics of Polymer Gel Systems Viewed Using NMR Spectroscopy

    Hidekazu Yasunaga; Masatoshi Kobayashi; Shingo Matsukawa; Hiromichi Kurosu; Isao Ando

    Recent fundamental research on hydro-polymer gel systems by means of NMR techniques such as pulse NMR, pulsed field-gradient spin-echo NMR, solid-state high-resolution NMR and NMR imaging methods have been reviewed. Such NMR techniques have elucidated structures and dynamics of gel systems as a function of the degree of crosslinking and their response process by an application of stimulus such as change in temperature, stress and electric field. It has been demonstrated that NMR techniques are powerful means of determining micro- and macroscopic structures and dynamics of more complicated systems with mobile components such as gel systems. © 1997 Academic Press Inc., 1997, Annual Reports on NMR Spectroscopy, 34 (C), 39 - 104, doi

  • Solid Polymer : Shielding & Electronic States

    KUROSU Hiromichi; Takeshi Yamanobe; Hiromichi Kurosu

    1995, Encyclopedia of NMR,John Wiley & Sons,New York, 4468-4474

  • 核磁気共鳴法

    KUROSU Hiromichi

    1995, 新高分子実験学5「高分子の構造」、講談社サイエンティクィック

  • Conformation and Molecular Motion of Poly(.GAMMA.-glutamate) with Long-n-Alkyl Side Chains in the Solid State and Liquid Crystalline State as Studied by High Resolution Solid State 13C NMR Spectroscopy. (2).

    加藤悦子; 黒木重樹; 黒子弘道; 安藤勲

    Sep. 1993, 高分子学会予稿集, 42 (10), 4219 - 4221, j_global

  • NMR Studies of High-order Structures of Solid Polymers

    KUROSU Hiromichi; H.Kurosu; S.Ando; H.Yoshimizu; I.Ando

    1993, Annual Reports on NMR Spectroscopy, 28, 189-275

  • APPEARANCE OF NEW STRUCTURES OF POLYALLENE IN THE SOLID-STATE AT LOW-TEMPERATURES AS OBSERVED BY VARIABLE-TEMPERATURE HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

    KH MIN; H KUROSU; ANDO, I; T YAMAMOTO; T KANBARA

    SOC POLYMER SCIENCE JAPAN, 1992, POLYMER JOURNAL, 24 (8), 829 - 831, web_of_science

    Introduction scientific journal

  • 高分子における計算科学の進歩

    KUROSU Hiromichi

    1991, 高分子(40巻11月号)

  • NMR Nuclear Shielding and Electronic Structure of Macromolecules

    KUROSU Hiromichi; I.Ando; T.Yamanobe; H.Kurosu; G.A.Webb

    1989, Annual Reports on NMR Spectroscopy, 22, 205-248

Books etc

  • Highly Reliable Metallization on Polymer and Their Fundamental Characteristics Toward Wearable Devices Applications

    KUROSU Hiromichi

    International Frequency Sensor Association Publishing, 2018

  • Specialist Periodical Reports Nuclear Magnetic

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2015, 431-455

  • Specialist Periodical Reports Nuclear Magnetic

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2014, 423-456

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2013, Vol. 42, pp. 420-449

  • Encyclopedia of NMR

    KUROSU Hiromichi; Takeshi Yamanobe (, Range: 分担)

    John Wiley & Sons, 2012

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2012, Vol. 41, pp.386-428

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2011, Vol. 40, pp.391-431

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2010, Vol. 39, pp. 322-362

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; T.Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2009, Vol. 38, pp.370-410

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2008, Vol. 37, pp.293-326

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2007, Vol. 36, pp.309-343

  • Modern Magnetic Resonance, NMR Chemical Shifts Based on Band Theory

    KUROSU Hiromichi; Takeshi Yamanobe (, Range: 分担)

    Springer, 2006

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2006, Vol. 35, pp389-432

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2005, Vol. 34, pp.415-470

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2004, Vol. 33, pp.386-438

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2003, Vol. 32, pp.361-400

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2002, Vol. 31, pp.353-387

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2001, Vol. 30, pp.377-411

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 2000, Vol. 29, pp.419-452

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 1999, Vol. 28, pp.364-394

  • Solid State NMR of Polymers

    KUROSU Hiromichi

    1998

  • Specialist Periodical Reports Nuclear Magnetic Resonance,Synthetic Macromolecules

    KUROSU Hiromichi; H. Kurosu; T. Yamanobe (, Range: 筆頭著者)

    The Royal Society of Chemistry, 1998, Vol. 27, pp.337-369

  • Solid Polymers : Shielding & Electronic States

    KUROSU Hiromichi

    Encyclopedia of NMR, John Wiley & Sons, New York, 1995, 4468-4474頁

  • 高分子の固体NMR

    KUROSU Hiromichi

    講談社サイエンティフィク, 1994

  • 各種分析手法におけるサンプリング・試料調製法と前処理技術

    KUROSU Hiromichi

    技術情報協会, 1993

  • 新材料開発とコンピュータケミストリー

    KUROSU Hiromichi

    化学工業日報社, 1989

Presentations

  • 固体NMRおよび量子化学計算を併用した構造解析

    KUROSU Hiromichi

    高分子学会・NMR研究会, May 2013, 東京

  • 固体NMRおよび量子化学計算を併用した高分子の高精度構造解析法の開発

    KUROSU Hiromichi

    繊維学会年次大会・繊維学会賞受賞講演, Jun. 2010, 東京

Teaching Experience

  • アパレル素材分子論演習 (Nara Women's University)

  • アパレル素材分子論 (Nara Women's University)

Association Memberships

  • The Nuclear Magnetic Resonance Society of Japan

  • The Chemical Society of Japan

  • The Society of Fiber Science and Technology, Japan

  • The Japan Society of Home Economics

  • The Society of Polymer Science, Japan

Works

  • 固体NMRを用いた高分子材料の研究

    Aug. 2013, Jul. - 2014



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