268 results on '"Hiroshi Jinnai"'
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2. INFLUENCE OF CONSOLIDATION METHOD FOR TEST SPECIMEN ON ACTIVITY INDEX TEST RESULTS OF MICRO POWDER FOR ULTRA-HIGH STRENGTH CONCRETE
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Hiroshi Jinnai
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Materials science ,Consolidation (soil) ,Architecture ,Building and Construction ,Activity index ,Composite material ,Test (assessment) ,High strength concrete - Published
- 2021
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3. Densely Arrayed Cage-Shaped Polymer Topologies Synthesized via Cyclopolymerization of Star-Shaped Macromonomers
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Takuya Isono, Hironori Marubayashi, Brian J. Ree, Kenji Tajima, Takuya Yamamoto, Toshifumi Satoh, Hiroshi Jinnai, Yoshinobu Mato, and Maho Sudo
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Mass spectrometry ,Polymers ,Organic Chemistry ,Polymer ,Star (graph theory) ,Network topology ,Inorganic Chemistry ,Crystallography ,chemistry ,Mathematical methods ,Cyclization ,Materials Chemistry ,Cage ,Cyclopolymerization - Abstract
This work reports a facile and versatile ring-opening metathesis polymerization of three- and four-armed star-shaped poly(epsilon-caprolactone) (PCL) macromonomers bearing a norbornenyl group at each chain end using Grubbs' third-generation catalyst under diluted condition to obtain graft polymers (GPs) comprising densely arrayed three- and four-armed cage-shaped grafted PCLs (GPCLs) with narrow dispersity (1.19-1.35) and a controllable number of cage repeating units up to 40 (molecular weight: similar to 320 000 g mol(-1)). The GPCLs were characterized using nuclear magnetic resonance spectroscopy, size exclusion chromatography, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The cyclopolymerization proceeded via repetitive rapid intramolecular reactions to form cage-shaped units followed by slow intermolecular propagation. This synthesis was applicable to star-shaped poly(L-lactide), poly(trimethylene carbonate), and poly(ethylene glycol). Investigating the structure-property relationships regarding crystallization behavior, hydrodynamic diameter, and viscosity revealed that cage-shaped topological side chains reduced the chain dimensions and mobility compared to their linear and cyclic counterparts.
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- 2021
4. FUNDAMENTAL STUDY ON SURFACE EROSION OF WOOD FOR EXTERIORS CAUSED BY PHOTODEGRADATION
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Yoshie Takahashi, Hiroshi Jinnai, Kaori Nagai, and Isamu Matsui
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Fundamental study ,Materials science ,Architecture ,Erosion ,Building and Construction ,Composite material ,Photodegradation - Published
- 2021
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5. Crack propagation behaviors in a nanoparticle‐filled rubber studied by in situ tensile electron microscopy
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Tomohiko Nagao, Hiroshi Jinnai, Akemi Kumagai, Daisuke Watanabe, and Tomohiro Miyata
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In situ ,Materials science ,Polymers and Plastics ,Nanoparticle ,Fracture mechanics ,law.invention ,Natural rubber ,law ,Transmission electron microscopy ,visual_art ,Ultimate tensile strength ,Materials Chemistry ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,Electron microscope ,Composite material - Published
- 2021
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6. MOISTURE CURINGEFFECT FOR CONCRETE IN STRUCTURE BY SHEATHING INPLACE ON HOTWEATHER
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Mahito Okura, Hiroshi Jinnai, and Tatsuki Kaneko
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Materials science ,Moisture ,Architecture ,Geotechnical engineering ,Building and Construction - Published
- 2021
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7. FUNDAMENTAL STUDY ON THE EFFECT OF PIGMENT USE AMOUNT ON THE COLOR OF COLORED MORTAR
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Hiroshi Jinnai
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Fundamental study ,Brightness ,Pigment ,Materials science ,Colored ,visual_art ,Architecture ,visual_art.visual_art_medium ,Building and Construction ,Composite material ,Mortar - Published
- 2021
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8. Nanoscale Stress Distribution in Silica-Nanoparticle-Filled Rubber as Observed by Transmission Electron Microscopy: Implications for Tire Application
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Tomohiro Miyata, Tomohiko Nagao, Daisuke Watanabe, Hiroshi Morita, Hiroshi Jinnai, Keizo Akutagawa, and Akemi Kumagai
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In situ ,Materials science ,technology, industry, and agriculture ,Stress distribution ,Silica nanoparticles ,Natural rubber ,Transmission electron microscopy ,visual_art ,Ultimate tensile strength ,visual_art.visual_art_medium ,General Materials Science ,Composite material ,Deformation (engineering) ,Nanoscopic scale - Abstract
Nanoparticle-filled rubber under tensile deformation was observed in situ by transmission electron microscopy (TEM), and the spatial distributions of the local maximum and minimum principal strains...
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- 2021
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9. BASIC STUDY ON PERFORMANCE OF AIR-ENTRAINING AND HIGH-RANGE WATER-REDUCING ADMIXTURE CONTAINING VISCOSITY MODIFYING AGENT
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Hiroshi Jinnai, Tadatsugu Kage, and Shinichi Koizumi
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Viscosity ,Range (particle radiation) ,Materials science ,Architecture ,Building and Construction ,Air entrainment ,Composite material - Published
- 2020
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10. Degradation of a Metal–Polymer Interface Observed by Element-Specific Focused Ion Beam-Scanning Electron Microscopy
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Katsunori Shimizu, Hiroaki Matsumoto, Miki Tsuchiya, Hiroshi Jinnai, Naoya Amino, Takashi Kakubo, and Akemi Kumagai
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Materials science ,Scanning electron microscope ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Focused ion beam ,law.invention ,Natural rubber ,law ,Electrochemistry ,General Materials Science ,Composite material ,Spectroscopy ,chemistry.chemical_classification ,Electron energy loss spectroscopy ,Vulcanization ,Surfaces and Interfaces ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,chemistry ,Electron diffraction ,visual_art ,visual_art.visual_art_medium ,Adhesive ,0210 nano-technology - Abstract
The degradation of a metal-polymer interface was studied in three dimensions using focused ion beam-scanning electron microscopy (FIB-SEM) with energy-dispersive X-ray spectroscopy. A brass-rubber interface, which is important for tires, was examined as an example of a metal-polymer interface. Brass-plated steel cords were embedded in rubber, which was then vulcanized. The brass-rubber interface was treated at 70 °C under 96% humidity for up to 14 days (a wet-heat aging treatment). FIB-SEM provided clear three-dimensional images of the adhesive layer consisting of brass (CuZn), CuxS, and ZnO/ZnS between the steel cords and rubber. During degradation, CuxS at the interfaces diffused into the rubber, resulting in the direct contact of bare steel with rubber. The lack of a substantial adhesive layer explained the degradation of mechanical properties after the wet-heat treatment. In addition, electron diffraction and electron energy loss spectroscopy revealed that the Cu2S crystals in the adhesive layer changed to crystal-like CuS during the degradation, which also caused a degradation of mechanical properties because a high Cu valence of x ≈ 2 in CuxS leads to stronger adhesion than a valence of x = 1.
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- 2020
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11. Strategy for Finely Aligned Gold Nanorod Arrays Using Polymer Brushes as a Template
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Hideyuki Mitomo, Yu Sekizawa, Yasutaka Matsuo, Satoshi Nakamura, Kuniharu Ijiro, Takeshi Higuchi, and Hiroshi Jinnai
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chemistry.chemical_classification ,Fabrication ,Materials science ,Cationic polymerization ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,Polymer ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Adsorption ,chemistry ,Electrochemistry ,General Materials Science ,Nanorod ,0210 nano-technology ,Nanoscopic scale ,Spectroscopy - Abstract
The development of a strategy for the assembly of nanoscale building blocks, in particular, anisotropic nanoparticles, into desired structures is important for the construction of functional materials and devices. However, control over the orientation of rod-shaped nanoparticles on a substrate for integration into solid-state devices remains challenging. Here, we report a strategy for the fabrication of finely aligned gold nanorod (GNR) arrays using polymer (DNA) brushes as a nanoscale template. The gold nanorods modified with cationic surface ligands were electrostatically adsorbed onto the DNA brush substrates under various conditions. The orientational behavior of the GNRs was examined by spectral analyses and transmission electron microtomography (TEMT). As a result, we found several important factors, such as moderate interaction between GNRs and polymers and polymer densities on the substrate, related to the vertical alignment of GNRs on the substrates. We also developed a purification method to remove the undesired adsorption of GNRs onto the arrays. Finally, we have succeeded in the fabrication of extensive vertical GNR arrays of high quality via the easy bottom-up process.
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- 2020
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12. Hierarchical structure of the triclinic α-phase crystal in nylon 6,12 mediated by two-dimensional confinement
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Shichen Yu, Ziwei Lai, Hiroshi Jinnai, Yan Cao, Nan Zheng, Masaki Ageishi, and Shuailin Zhang
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Materials science ,Nanostructure ,02 engineering and technology ,Crystal structure ,Triclinic crystal system ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Symmetry (physics) ,0104 chemical sciences ,law.invention ,Crystal structure prediction ,Crystal ,chemistry.chemical_compound ,Crystallography ,Nylon 6 ,chemistry ,law ,Crystallization ,0210 nano-technology - Abstract
It has been recognized that macromolecular chains can self-assemble into a hierarchical structure from lamellae to spherulites in bulk crystallization. However, little account has been taken of crystal symmetry effects on the hierarchical nanostructure in polymers under cylindrical confinement. In this research, a model polymer, nylon 6,12, most commonly occurring in the triclinic α phase, was chosen in order to demonstrate the effect of triclinic symmetry on the 2D-constrained polymer nanostructure. The self-arranging unit of nylon 6,12 takes various forms, including stems, unit cells, hydrogen-bonded sheets, lamellae and complex spherulites, which is an essential structural feature for investigating hierarchical nanostructure. The rod nanostructure in confinement was examined by cross-checking electron and X-ray diffraction techniques. It is found that the a* axis of the α-phase cell is inclined at about ±6–11° to the rod long axis within the a*b* plane around the c axis (c axis ⊥ rod long axis). The rotation of the a*b* plane most likely results from the impact of the triclinic symmetry on the molecular chain packing under 2D confinement. A mechanism for this a*b* plane tilting is proposed.
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- 2020
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13. CONSIDERATION IN REPEATABILITY OF ACTIVITY INDEX TEST RESULTS OF MICRO POWDER FOR ULTRA-HIGH STRENGTH CONCRETE BASED ON MORTAR
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Hiroshi Jinnai
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Materials science ,Architecture ,Building and Construction ,Repeatability ,Composite material ,Mortar ,Activity index ,High strength concrete ,Test (assessment) - Published
- 2020
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14. Single-Macromolecular Level Imaging of a Hydrogel Structure
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Takayuki Nonoyama, Sedlacik Tomas, Jian Ping Gong, Ryuji Kiyama, and Hiroshi Jinnai
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Materials science ,Transmission electron microscopy ,Self-healing hydrogels ,Resolution (electron density) ,Direct observation ,Nanotechnology ,Nanometre ,Wetting ,Nanoscopic scale ,Macromolecule - Abstract
Hydrogels are promising materials for several applications, including cell scaffolds and artificial load-bearing substitutes (cartilages, ligaments, tendons, etc.). Direct observation of the nanoscale polymer network of hydrogels is essential in understanding its properties. However, imaging of individual network strands at the molecular level is not achieved yet due to the lack of suitable methods. Herein, for the first time, we developed a novel mineral-staining method and network fixation method for transmission electron microscopy observation to visualize the hydrogel network in its unperturbed conformation with nanometer resolution. Surface network observation indicates that the length of surface dangling chains, which play a major role in friction and wetting, can be estimated from the gel mesh size. Moreover, bulk observations reveals a hierarchical formation mechanism of gel heterogeneity. These observations have the great potential to advance gel science by providing comprehensive perspective that link bulk gel properties with nanoscale.
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- 2021
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15. Self-Assembled Morphologies of Lamella-Forming Block Copolymers Confined in Conical Nanopores
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Kookheon Char, Hiroshi Jinnai, Xiejun Hu, Youngkeol Kim, Akemi Kumagai, An-Chang Shi, and Baohui Li
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Materials science ,Nanostructure ,Polymers and Plastics ,Organic Chemistry ,02 engineering and technology ,Conical surface ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Self assembled ,Inorganic Chemistry ,Nanopore ,Lamella (surface anatomy) ,Chemical engineering ,Materials Chemistry ,Copolymer ,0210 nano-technology ,Nanoscopic scale - Abstract
Block copolymers (BCPs) under nanoscale confinement can self-assemble to form novel nanostructures that are not available in the bulk state. Particularly, the ordering process of block copolymers a...
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- 2019
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16. Cascade Self-Organization of Shish Kebabs in Fibers Spun from Polymer Solutions: Crystalline Fibrils Bridging Neighboring Kebabs Discovered by Transmission Electron Microtomography
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Takeji Hashimoto, Takaaki Toriyama, Hiroki Murase, and Hiroshi Jinnai
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chemistry.chemical_classification ,Phase transition ,Bridging (networking) ,Materials science ,Polymers and Plastics ,Organic Chemistry ,macromolecular substances ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Fibril ,Epitaxy ,01 natural sciences ,0104 chemical sciences ,law.invention ,Inorganic Chemistry ,chemistry ,Chemical physics ,law ,Cascade ,Materials Chemistry ,Laplace pressure ,Crystallization ,0210 nano-technology - Abstract
In fibers spun from polymer solutions, we investigated self-organization of ordered shish kebabs via the cascade evolution of various dissipative structures through multistep phase transitions at multiple length scales. We used transmission electron microtomography to discover for the first time crystalline fibrils with diameters of ∼10 nm that orthogonally bridge neighboring kebabs epitaxially overgrown from shishs. The fibrils evolved during the late-stage self-organization processes of the shish kebabs. The fibrils were classified as completely bridging fibrils and pairs of broken fibrils facing each other; the broken fibrils were formed by the following two steps, first by the flow-induced burst of the bridging domains driven by Laplace pressure and subsequent crystallization involved in the burst domains. The bridging and broken fibrils were observed at interkebab distances smaller and larger than the critical length of ∼80 nm, respectively. The bridging fibrils and the cores of the broken fibrils ha...
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- 2019
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17. FUNDAMENTAL STUDY ON MORTAR USING RECOVERED FINE AGGREGATE
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Hiroshi Jinnai, Sumie Suzuki, Yoshihiro Masuda, Tadatsugu Kage, and Hiroyuki Tanano
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Fundamental study ,Compressive strength ,Aggregate (composite) ,Materials science ,Architecture ,Particle-size distribution ,Building and Construction ,Composite material ,Mortar - Published
- 2019
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18. FUNDAMENTAL STUDY ON COLORED MORTAR USING CONCRETE PIGMENTS WITH DIFFERENT WATER BINDER RATIO
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Yoshiyuki Koyama and Hiroshi Jinnai
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Brightness ,Fundamental study ,Pigment ,Compressive strength ,Materials science ,Colored ,visual_art ,Architecture ,visual_art.visual_art_medium ,Building and Construction ,Mortar ,Composite material - Published
- 2019
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19. Visualization of chemical bonding in a silica-filled rubber nanocomposite using STEM-EELS
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Yohei Sato, Kuwauchi Yasufumi, Wakana Miyoshi, and Hiroshi Jinnai
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Materials science ,Science ,Composite number ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,Natural rubber ,Nanoscience and technology ,Scanning transmission electron microscopy ,Composite material ,Multidisciplinary ,Nanocomposite ,Adhesion ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical bond ,visual_art ,visual_art.visual_art_medium ,Medicine ,Adhesive ,0210 nano-technology ,Layer (electronics) - Abstract
In nanocomposites, the adhesion between nanofillers and the polymeric matrix is key to the mechanical properties. The strength and spatial distribution of the adhesive layer around the nanofillers are important, particularly the presence of chemical bonding between the nanofillers and matrix. In this work, we studied a styrene-butadiene rubber composite filled with silica nanoparticles to visualize the spatial distribution of the adhesive layer. A silane coupling agent (SCA) was added to the nanocomposite for strong adhesion. The reaction involving the SCA on the silica surface was investigated by scanning transmission electron microscopy combined with electron energy-loss spectroscopy. Si-L2,3 spectra of the silica-filled rubber nanocomposite without the SCA were the same around the nanofillers, whereas in the nanocomposite containing the SCA the spectra were position-dependent. The spectra were fitted with the intensity profiles of the Si-L2,3 spectra of silica and SCA by multiple linear least-squares fitting. The fitting coefficients of silica and SCA were used to map the spatial distribution of the chemical bonding between silica and rubber chains. Chemical bonding was observed around the silica nanoparticles but not in the SBR matrix region, providing direct evidence of the reinforcing mechanism in the silica-filled rubber nanocomposite.
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- 2020
20. Networks with controlled chirality via self-assembly of chiral triblock terpolymers
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Ishan Prasad, Zhi Hong Xie, Edwin L. Thomas, Yu-Chueh Hung, Po Ting Chiu, Rong-Ming Ho, Jing Yu Lee, Hiroshi Jinnai, Chih Ying Yang, Hsiao Fang Wang, and Jing Cherng Tsai
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Materials science ,High Energy Physics::Lattice ,Materials Science ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Chain (algebraic topology) ,Phase (matter) ,Copolymer ,Computer Science::Databases ,Research Articles ,Multidisciplinary ,Chemical Physics ,High Energy Physics::Phenomenology ,SciAdv r-articles ,Chiral phase ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,Monomer ,chemistry ,Chemical physics ,Self-assembly ,0210 nano-technology ,Chirality (chemistry) ,Gyroid ,Research Article - Abstract
By taking advantage of chirality transfer, nanonetwork with controlled chirality can be obtained from self-assembly., Nanonetwork-structured materials can be found in nature and synthetic materials. A double gyroid (DG) with a pair of chiral networks but opposite chirality can be formed from the self-assembly of diblock copolymers. For triblock terpolymers, an alternating gyroid (GA) with two chiral networks from distinct end blocks can be formed; however, the network chirality could be positive or negative arbitrarily, giving an achiral phase. Here, by taking advantage of chirality transfer at different length scales, GA with controlled chirality can be achieved through the self-assembly of a chiral triblock terpolymer. With the homochiral evolution from monomer to multichain domain morphology through self-assembly, the triblock terpolymer composed of a chiral end block with a single-handed helical polymer chain gives the chiral network from the chiral end block having a particular handed network. Our real-space analyses reveal the preferred chiral sense of the network in the GA, leading to a chiral phase.
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- 2020
21. BASIC STUDY ON HIGH STRENGTH CONCRETE USING FERRONICKEL SLAG FINE AGGREGATE IN AIR-DRY CONDITION
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Mitsutaka Hayakawa, Hiroshi Jinnai, and Tomoya Ishiguro
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Compressive strength ,Materials science ,Aggregate (composite) ,Architecture ,Metallurgy ,Ferroalloy ,Building and Construction ,Slag (welding) ,High strength concrete - Published
- 2018
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22. Interfacial morphologies and associated processes of multicomponent polymers
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Hiroshi Jinnai
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chemistry.chemical_classification ,Spinodal ,Materials science ,Polymers and Plastics ,Time evolution ,Non-equilibrium thermodynamics ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,Electron tomography ,Chemical engineering ,Microscopy ,Materials Chemistry ,Copolymer ,Polymer blend ,0210 nano-technology - Abstract
This review describes contemporary advancements in the study of interfacial morphologies and associated processes of multicomponent polymers. A particular emphasis is placed on the use of three-dimensional (3D) microscopy, for example, transmission electron microtomography (TEMT) and laser scanning confocal microscopy (LSCM). The time evolution of a spinodal interface during the phase separation of a polymer blend was followed by LSCM. The obtained 3D interfacial morphology was analyzed by differential geometry. The scalability was tested using curvature distributions. 3D nanoimaging, that is, TEMT, was applied to examine the stability and dynamics of complex block copolymer (BCP) morphologies, and novel structural data were directly assessed according to the 3D volume data. This review also examines two essential developments in the time-dependent in situ electron tomography of polymer materials to study the dynamic processes of BCPs. The 3D microscopy-based structural information renders an important perspective into the studies of nonlinear nonequilibrium occurrences as well as the statistical physics of long-chain-bearing moieties. Interfacial morphologies and associated processes in multicomponent polymer systems, e.g., block copolymers (BCPs) and polymer blends, are examined using three-dimensional (3D) microscopies. Because of the rich structural information in 3D images, various new types of structural parameters, including chain conformation inside BCPs nanodomains, chain packing frustration in BCPs, Genus etc., can be obtained. The stability and interfacial dynamics are also discussed.
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- 2018
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23. Development of a three-dimensional tomography holder for in situ tensile deformation for soft materials
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Keizo Akutagawa, Takeshi Higuchi, Takashi Gondo, Hiroya Miyazaki, Akemi Kumagai, and Hiroshi Jinnai
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Materials science ,02 engineering and technology ,Deformation (meteorology) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Tilt (optics) ,Electron tomography ,Natural rubber ,Structural Biology ,Transmission electron microscopy ,visual_art ,Ultimate tensile strength ,visual_art.visual_art_medium ,Radiology, Nuclear Medicine and imaging ,Composite material ,Thin film ,0210 nano-technology ,Instrumentation ,Nanoscopic scale - Abstract
An in situ straining holder capable of tensile deformation and high-angle tilt for electron tomography was developed for polymeric materials. The holder has a dedicated sample cartridge, on which a variety of polymeric materials, such as microtomed thin sections of bulk specimens and solvent-cast thin films, can be mounted. Fine, stable control of the deformation process with nanoscale magnification was achieved. The holder allows large tensile deformation (≃800 μm) with a large field of view (800 × 200 μm before the deformation), and a high tilt angle (±75°) during in situ observations. With the large tensile deformation, the strain on the specimen can be as large as 26, at least one order of magnitude larger than the holder's predecessor. We expect that meso- and microscopic insights into the dynamic mechanical deformation and fracture processes of polymeric materials can be obtained by combining the holder with a transmission electron microscope equipped with an energy filter. The filter allows zero-loss imaging to improve the resolution and image contrast for thick specimens. We used this technique to study the deformation process in a silica nanoparticle-filled isoprene rubber.
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- 2018
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24. Stabilizing the Ordered Bicontinuous Double Diamond Structure of Diblock Copolymer by Configurational Regularity
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Takeshi Higuchi, Hiroshi Jinnai, Chih Hsuan Lin, Jing Cherng Tsai, Hsin-Lung Chen, and Takeji Hashimoto
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Materials science ,Polymers and Plastics ,Organic Chemistry ,Diamond ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Inorganic Chemistry ,Crystal ,Crystallography ,Phase (matter) ,Tacticity ,Metastability ,0103 physical sciences ,Materials Chemistry ,Melting point ,engineering ,Copolymer ,010306 general physics ,0210 nano-technology ,Gyroid - Abstract
We investigate the formation of the ordered bicontinuous structures in a stereoregular diblock copolymer, isotactic polypropylene-block-polystyrene (iPP-b-PS), in which the minority PP block possessed isotactic configuration. This diblock displayed the conventional ordered bicontinuous double gyroid (OBDG) morphology upon heating above the crystal melting point of the iPP block from the as-cast state. The OBDG phase remained stable in the heating process up to the order–disorder transition. In the subsequent cooling process from the nearly disordered state, the OBDG phase first developed, but when the temperature was sufficiently low, an order–order transition from OBDG to the ordered bicontinuous double diamond (OBDD) phase occurred, and OBDD eventually became the dominant structure. The results attested that OBDD and OBDG represented the thermodynamically stable structure at the lower and the higher temperature, respectively, and the OBDG morphology formed in the as-cast state was metastable. The presen...
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- 2018
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25. In situ Three-dimensional Observation of Rubber Materials Under Tensile Deformation
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Hiroshi Jinnai and Takeshi Higuchi
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In situ ,Materials science ,Natural rubber ,visual_art ,Ultimate tensile strength ,visual_art.visual_art_medium ,Composite material ,Deformation (meteorology) - Published
- 2018
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26. Anatomy of triply-periodic network assemblies: characterizing skeletal and inter-domain surface geometry of block copolymer gyroids
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Ishan Prasad, Hiroshi Jinnai, Edwin L. Thomas, Rong-Ming Ho, and Gregory M. Grason
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Condensed Matter - Materials Science ,Materials science ,Inter-domain ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,02 engineering and technology ,General Chemistry ,Thread (computing) ,Condensed Matter - Soft Condensed Matter ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Curvature ,01 natural sciences ,0104 chemical sciences ,Lyotropic liquid crystal ,Copolymer ,Soft Condensed Matter (cond-mat.soft) ,Surface geometry ,Soft matter ,0210 nano-technology ,Biological system ,Gyroid - Abstract
Triply-periodic networks (TPNs), like the well-known gyroid and diamond network phases, abound in soft matter assemblies, from block copolymers (BCPs), lyotropic liquid crystals and surfactants to functional architectures in biology. While TPNs are, in reality, volume-filling patterns of spatially-varying molecular composition, physical and structural models most often reduce their structure to lower-dimensional geometric objects: the {\it 2D interfaces} between chemical domains; and the {\it 1D skeletons} that thread through inter-connected, tubular domains. These lower-dimensional structures provide a useful basis of comparison to idealized geometries based on triply-periodic minimal, or constant-mean curvature surfaces, and shed important light on the spatially heterogeneous packing of molecular constituents that form the networks. Here, we propose a simple, efficient and flexible method to extract a 1D skeleton from 3D volume composition data of self-assembled networks. We apply this method to both self-consistent field theory predictions as well as experimental electron microtomography reconstructions of the double-gyroid phase of an ABA triblock copolymer. We further demonstrate how the analysis of 1D skeleton, 2D inter-domain surfaces, and combinations therefore, provide physical and structural insight into TPNs, across multiple length scales. Specifically, we propose and compare simple measures of {\it network chirality} as well as {\it domain thickness}, and analyze their spatial and statistical distributions in both ideal (theoretical) and non-ideal (experimental) double gyroid assemblies., 13 pages, 7 figures, 3 pages supporting pdf
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- 2018
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27. Cellulose nanofiber-reinforced rubber composites prepared by TEMPO-functionalization and elastic kneading
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Morinobu Endo, Ayumi Kurashima, Takashi Miura, Hironori Marubayashi, Toru Noguchi, Akira Koyama, Akira Isogai, Hiroshi Jinnai, Ken ich Niihara, Akemi Kumagai, and Rie Iwamoto
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Materials science ,Composite number ,General Engineering ,Diethylene glycol ,Reinforced rubber ,02 engineering and technology ,Dynamic mechanical analysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Natural rubber ,visual_art ,Nanofiber ,Ultimate tensile strength ,Ceramics and Composites ,visual_art.visual_art_medium ,Cellulose ,Composite material ,0210 nano-technology - Abstract
Aqueous dispersion consisting of 2,2,6,6-tegramethylpyperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TEMPO-CNFs), dodecyltrimethylammonium chloride (DTMACl), and diethylene glycol (DEG) was oven-dried at 40 °C for 1 d to prepare a dried product. The soft and bulky TEMPO-CNF/DTMACl/DEG material was added to a carboxy group-containing nitrile-butadiene rubber (XNBR) followed by removal of all the DEG molecules by vacuum drying at 80 °C for 8 h. The mixture was then subjected to kneading with high shear forces using a two-roll mill at 20–30 °C (i.e., elastic kneading), followed by pressing at 170 °C for 20 min to prepare cross-linked XNBR composite sheets consisting of TEMPO-CNF and DTMACl. The XNBR composite sheet containing 9.9 vol% TEMPO-CNF had an average tensile strength, storage modulus at 23 °C, work of fracture, and elongation at break of 19 MPa, 47 MPa, 2.7 MJ/m3, and 230%, respectively, whereas those of the reference cross-linked XNBR sheet were 11 MPa, 11 MPa, 0.9 MJ/m3, and 220%, respectively. Scanning transmission electron microscopy observation revealed unique fibrillated and cluster-like structures of the TEMPO-CNF were likely responsible for the excellent mechanical and thermal properties. The proposed process is industrially viable for conventional kneading processes to prepare composite rubber sheets with good mechanical and thermal properties.
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- 2021
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28. Synthesis of ordered carbonaceous frameworks from organic crystals
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Hitoshi Kasai, Hisashi Konaka, Hirofumi Nobukuni, Tomoyuki Akutagawa, Hiroshi Jinnai, Kazuhide Kamiya, Yuichiro Hayasaka, Norihisa Hoshino, Fumito Tani, Tetsuya Hirota, Yoshiaki Matsuo, Hirotomo Nishihara, Yasuhiro Yamada, Jun Maruyama, Takuya Kamimura, Mao Ohwada, Yoshitaka Koseki, Kenta Matsuura, Takeshi Higuchi, and Shingi Yamaguchi
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Materials science ,Science ,Supramolecular chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,engineering.material ,010402 general chemistry ,Electrocatalyst ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Crystal ,chemistry.chemical_compound ,Multidisciplinary ,Diacetylene ,Carbonization ,General Chemistry ,021001 nanoscience & nanotechnology ,Porphyrin ,0104 chemical sciences ,chemistry ,Chemical engineering ,engineering ,Noble metal ,0210 nano-technology ,Carbon - Abstract
Despite recent advances in the carbonization of organic crystalline solids like metal-organic frameworks or supramolecular frameworks, it has been challenging to convert crystalline organic solids into ordered carbonaceous frameworks. Herein, we report a route to attaining such ordered frameworks via the carbonization of an organic crystal of a Ni-containing cyclic porphyrin dimer (Ni2-CPDPy). This dimer comprises two Ni–porphyrins linked by two butadiyne (diacetylene) moieties through phenyl groups. The Ni2-CPDPy crystal is thermally converted into a crystalline covalent-organic framework at 581 K and is further converted into ordered carbonaceous frameworks equipped with electrical conductivity by subsequent carbonization at 873–1073 K. In addition, the porphyrin’s Ni–N4 unit is also well retained and embedded in the final framework. The resulting ordered carbonaceous frameworks exhibit an intermediate structure, between organic-based frameworks and carbon materials, with advantageous electrocatalysis. This principle enables the chemical molecular-level structural design of three-dimensional carbonaceous frameworks., Carbon-based materials are promising alternatives to noble metal catalysts, but their structures are typically disordered and difficult to control. Here, the authors obtain ordered carbonaceous frameworks with advantageous electrocatalytic properties via the carbonization of nickel-containing porphyrin dimer networks.
- Published
- 2017
29. Three-dimensional visualization and characterization of polymeric self-assemblies by Transmission Electron Microtomography
- Author
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Yuichi Ikuhara, Kees Joost Batenburg, Hiroshi Jinnai, Takeshi Higuchi, Akihito Kumamoto, Xiaodong Zhuge, and Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands
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Nanostructure ,Microscope ,Materials science ,business.industry ,Nanotechnology ,02 engineering and technology ,General Medicine ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Characterization (materials science) ,law.invention ,Nanomaterials ,Transmission electron microscopy ,law ,Computer data storage ,Copolymer ,0210 nano-technology ,business ,Nanoscopic scale - Abstract
Self-assembling structures and their dynamical processes in polymeric systems have been investigated using three-dimensional transmission electron microscopy (3D-TEM). Block copolymers (BCPs) self-assemble into nanoscale periodic structures called microphase-separated structures, a deep understanding of which is important for creating nanomaterials with superior physical properties, such as high-performance membranes with well-defined pore size and high-density data storage media. Because microphase-separated structures have become increasingly complicated with advances in precision polymerization, characterizing these complex morphologies is becoming increasingly difficult. Thus, microscopes capable of obtaining 3D images are required. In this article, we demonstrate that 3D-TEM is an essential tool for studying BCP nanostructures, especially those self-assembled during dynamical processes and under confined conditions. The first example is a dynamical process called order-order transitions (OOTs). Upon changing temperature or pressure or applying an external field, such as a shear flow or electric field, BCP nanostructures transform from one type of structure to another. The OOTs are examined by freezing the specimens in the middle of the OOT and then observing the boundary structures between the preexisting and newly formed nanostructures in three-dimensions. In an OOT between the bicontinuous double gyroid and hexagonally packed cylindrical structures, two different types of epitaxial phase transition paths are found. Interestingly, the paths depend on the direction of the OOT. The second example is BCP self-assemblies under confinement that have been examined by 3D-TEM. A variety of intriguing and very complicated 3D morphologies can be formed even from the BCPs that self-assemble into simple nanostructures, such as lamellar and cylindrical structures in the bulk (in free space). Although 3D-TEM is becoming more frequently used for detailed morphological investigations, it is generally used to study static nanostructures. Although OOTs are dynamical processes, the actual experiment is done in the static state, through a detailed morphological study of a snapshot taken during the OOT. Developing time-dependent nanoscale 3D imaging has become a hot topic. Here, the two main problems preventing the development of in situ electron tomography for polymer materials are addressed. First, the staining protocol often used to enhance contrast for electrons is replaced by a new contrast enhancement based on chemical differences between polymers. In this case, no staining is necessary. Second, a new 3D reconstruction algorithm allows us to obtain a high-contrast, quantitative 3D image from fewer projections than is required for the conventional algorithm to achieve similar contrast, reducing the number of projections and thus the electron beam dose. Combining these two new developments is expected to open new doors to 3D in situ real-time structural observation of polymer materials.
- Published
- 2017
30. Direct three-dimensional imaging of the fracture of fiber-reinforced plastic under uniaxial extension: Effect of adhesion between fibers and matrix
- Author
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Teruhisa Tanaka, Haruko Saito, Hiroshi Jinnai, Yuko Aoyanagi, Takaaki Mihara, Hiroshi Morita, and Takeshi Higuchi
- Subjects
Void (astronomy) ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Glass fiber ,02 engineering and technology ,Fibre-reinforced plastic ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Nylon 6 ,chemistry ,Cavitation ,Ultimate tensile strength ,Materials Chemistry ,Surface modification ,Composite material ,0210 nano-technology ,Stress concentration - Abstract
The three-dimensional morphology and a mechanical property of a fiber-reinforced plastic (FRP) have been investigated under uniaxial extension. A custom tensile apparatus for X-ray computerized tomography was developed for this purpose. The two FRPs used in the present study consisted of nylon 6 with glass fibers. In one of the FRPs, the fiber surfaces were treated to adhere to the nylon 6. It was observed that the fibers tended to align along the extension axis, and that cavitation occurred simultaneously during the extension. In the case of the FRP with glass fibers without any surface modification (hereafter, referred as “neat” glass fibers), void formation was dominant over the whole extension range. In the case of the FRP with surface treatment, fiber alignment occurred first and was followed by void formation. A numerical simulation was carried out to study the stress concentration around a fiber with such morphological changes during extension. Through quantitative measurements of fiber orientation and void volume, together with predictions from the numerical simulations, the effect of fiber/matrix adhesion on the morphological developments and mechanical properties of the FRPs was discussed.
- Published
- 2017
- Full Text
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31. STUDY ON INFLUENCE OF COARSE AGGREGATE ON YOUNG'S MODULUS OF HIGH STRENGTH CONCRETE
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Satoshi Watanabe, Hiroshi Jinnai, and Shusuke Kuroiwa
- Subjects
symbols.namesake ,Materials science ,Aggregate (composite) ,Architecture ,symbols ,Aggregate modulus ,Young's modulus ,Building and Construction ,Composite material ,High strength concrete - Published
- 2017
- Full Text
- View/download PDF
32. Liquid Marbles from Polymer Particles: Formation Mechanism, Physical Characterizations, and Applications
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Atsushi Takahara, Shigesaburo Ogawa, Daisuke Matsukuma, Hiroshi Jinnai, Hui Wu, and Hirohmi Watanabe
- Subjects
Materials science ,Polymers and Plastics ,Materials Science (miscellaneous) ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surface energy ,0104 chemical sciences ,Polymer particle ,Chemical engineering ,Polymer chemistry ,Chemical Engineering (miscellaneous) ,0210 nano-technology ,Mechanism (sociology) ,General Environmental Science - Published
- 2017
- Full Text
- View/download PDF
33. Atomic-scale Observation of Polymer-chain Conformations Using Scanning Transmission Electron Microscopy
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Tomohiro Miyata, Takashi Ishizone, Raita Goseki, and Hiroshi Jinnai
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chemistry.chemical_classification ,Materials science ,chemistry ,Chain (algebraic topology) ,Chemical physics ,Scanning transmission electron microscopy ,Polymer ,Instrumentation ,Atomic units - Published
- 2020
- Full Text
- View/download PDF
34. Scattering patterns and stress-strain relations on phase-separated ABA block copolymers under uniaxial elongating simulations
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Tetsuo Tominaga, Hiroshi Jinnai, Keizo Akutagawa, and Katsumi Hagita
- Subjects
Materials science ,Strain (chemistry) ,Scattering ,Stress–strain curve ,02 engineering and technology ,General Chemistry ,Neutron scattering ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Molecular dynamics ,Chemical physics ,Phase (matter) ,Domain (ring theory) ,Copolymer ,0210 nano-technology - Abstract
To develop molecularly based interpretations of the two-dimensional scattering patterns (2DSPs) of phase-separated block copolymers (BCPs), we performed coarse-grained molecular dynamics simulations of ABA tri-BCPs under uniaxial stretching for block-fractions where the A-segment (glassy domain) is smaller than the B-segment (rubbery domain), and estimated the behaviour of their 2DSPs. In BCP stretching experiments, mechanical properties are generally evaluated using a stress–strain curve. We obtained 2DSPs with different contrasts for the A- and B-segments, which are indicative of the differences between X-ray and neutron scattering experiments. The small- and wide-angle behaviours of the 2DSPs originate from the morphologies of the phase-separated domains and local bond orientations, respectively. When the block-fractions are changed for a constant stress value on the stress–strain (SS) curve, the brightness of the spots in the wide-angle region of the A- and B-segment-dominant 2DSPs decreases and increases with increasing strain, respectively. We can regard the systematic changes in the small-angle 2DSPs of the glassy domain and the wide-angle 2DSPs of the rubbery domain with changes in the SS-curve as a structure–property relationship.
- Published
- 2019
35. Transmission Electron Microscopy
- Author
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Hiroshi Jinnai, Xi Jiang, and Takeshi Higuchi
- Subjects
Materials science ,Optical microscope ,Transmission electron microscopy ,law ,Nanotechnology ,Electron ,Electron microscope ,law.invention ,Characterization (materials science) - Abstract
Electron microscopy is a versatile scientific technique used in the investigation and characterization of materials science, biology, and life science. The principle of electron microscopy is similar to optical microscopy but uses electrons to illuminate and magnify specimens instead of light.
- Published
- 2019
- Full Text
- View/download PDF
36. Scanning Electron Microscopy
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Xi Jiang, Hiroshi Jinnai, and Takeshi Higuchi
- Subjects
Nanostructure ,Materials science ,Morphology (linguistics) ,Scanning electron microscope ,law ,Nanotechnology ,Electron microscope ,law.invention - Abstract
Scanning electron microscopy (SEM), an important member of the electron microscopy family, is a versatile instrument widely used in various fields such as nanotechnology, biology, and the life sciences for imaging of micro- and nanostructure morphology and characterizations of chemical composition of various materials.
- Published
- 2019
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- View/download PDF
37. Elucidation of oxygen reduction reaction and nanostructure of platinum-loaded graphene mesosponge for polymer electrolyte fuel cell electrocatalyst
- Author
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Tomohiko Nagao, Keita Nomura, Tetsuya Mashio, Yoshihisa Furuya, Hirotomo Nishihara, Masashi Ito, Hiroshi Jinnai, Atsushi Ohma, and Takashi Kyotani
- Subjects
Materials science ,Rotating ring-disk electrode ,Graphene ,General Chemical Engineering ,Catalyst support ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,Electrochemistry ,0210 nano-technology ,Mesoporous material ,Platinum ,Ionomer - Abstract
A graphene mesosponge (GMS), which has a sponge-like mesoporous framework, was applied to a catalyst support for polymer electrolyte fuel cell. Platinum loaded GMS (Pt/GMS) was prepared as electrocatalyst for oxygen reduction reaction (ORR) measurement and compared with platinum loaded Ketjen black (Pt/KB). ORR activity was evaluated by rotating ring disk electrode (RRDE) method to analyze hydrogen peroxide (H2O2) evolution behavior as an indicator of ionomer coverage on Pt. It was found that the ORR area specific activity of Pt/GMS was 1.2 times higher than that of Pt/KB with less H2O2 yield, mainly attributed to the lower ionomer coverage at Pt/GMS. It was also observed by transmission electron microtomography (3D-TEM) that Pt/GMS has a lot of pores between the sponge-like mesoporous framework with Pt nanoparticles therein. On the other hand, Pt/KB showed smoother agglomerate shapes with Pt nanoparticles inside the KB agglomerates mainly. Considering the frame-like mesoporous carbon network having hydrophobic basal nanosurface of the graphene of GMS and the aqueous electrolyte in this system, it is concluded that the ionomer can form self-aggregation with its hydrophobic domain inside, resulting in ineffective coverage of the ionomer on the nanostructure of GMS and the Pt nanoparticles in the GMS agglomerates.
- Published
- 2021
- Full Text
- View/download PDF
38. Preparation of high‐performance carbon nanotube/polyamide composite materials by elastic high‐shear kneading and improvement of properties by induction heating treatment
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Toru Noguchi, Fukushi Masanori, Kawamoto Keiichi, Morinobu Endo, Hiroshi Jinnai, Ken Nakajima, and Niihara Kenichi
- Subjects
Shear (sheet metal) ,Materials science ,Induction heating ,Polymers and Plastics ,law ,Composite number ,Polyamide ,Materials Chemistry ,General Chemistry ,Carbon nanotube ,Composite material ,Surfaces, Coatings and Films ,law.invention - Published
- 2021
- Full Text
- View/download PDF
39. Ultra-low dielectric properties of porous polyimide thin films fabricated by using the two kinds of templates with different particle sizes
- Author
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Hitoshi Kasai, Yumi Kourakata, Tsunenobu Onodera, Hidetoshi Oikawa, and Hiroshi Jinnai
- Subjects
Materials science ,Polymers and Plastics ,Organic Chemistry ,Transmission Electron Microtomography ,02 engineering and technology ,Dielectric ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Template ,Electron tomography ,Materials Chemistry ,Particle ,Thin film ,Composite material ,0210 nano-technology ,Porosity ,Polyimide - Abstract
Porous polyimide (PI) thin films have been fabricated successfully by using silica microparticles (MPs) with different particle sizes as a template, and the three dimensional porous structure has been observed clearly by mean of transmission electron microtomography. The measured values of dielectric constant (e) decreased remarkably by introducing a porous structure, compared with ordinary PI thin films. Especially, the porosity evidently increased (ca. 10%) by suitably employing silica MPs having different particle sizes, and then the value of e was further reduced. Bruggeman model could reproduce nearly the relationship between the value of e and porosity.
- Published
- 2021
- Full Text
- View/download PDF
40. Observation of constraint surface dynamics of polystyrene thin films by functionalization of a silsesquioxane cage
- Author
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Shigesaburo Ogawa, Masaki Takata, Masanao Sato, Taiki Hoshino, Shiki Nojima, Atsushi Takahara, Tomoyasu Hirai, Hiroshi Jinnai, So Fujinami, Daiki Murakami, and Yuji Higaki
- Subjects
Materials science ,Polymers and Plastics ,Organic Chemistry ,02 engineering and technology ,Substrate (electronics) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Silsesquioxane ,chemistry.chemical_compound ,chemistry ,Dynamic light scattering ,Chemical engineering ,0103 physical sciences ,Polymer chemistry ,Materials Chemistry ,Surface modification ,Polystyrene ,Thin film ,010306 general physics ,0210 nano-technology ,Glass transition ,Layer (electronics) - Abstract
The surface dynamics of polyhedral oligomeric silsesquioxane (POSS)-functionalized polystyrene (PS-POSS) thin films above the glass transition temperature were studied by grazing-incidence X-ray photon correlation spectroscopy in order to elucidate the effects of POSS at the end of the polystyrene chains. Much slower fluctuations were observed in the surface of PS-POSS thin films than in the polystyrene thin films, despite the negligible difference in their bulk viscosity. Quantitative analysis based on fluctuation-dissipation theorem indicated that there is a high-viscosity layer at the surface of the PS-POSS films, and that the substrate interface originated from POSS segregation.
- Published
- 2016
- Full Text
- View/download PDF
41. Swollen structure and electrostatic interactions of polyelectrolyte brush in aqueous solution
- Author
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Motoyasu Kobayashi, Atsushi Takahara, Yuji Higaki, Daiki Murakami, and Hiroshi Jinnai
- Subjects
Aqueous solution ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Ionic bonding ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrostatics ,01 natural sciences ,Polyelectrolyte ,Dissociation (chemistry) ,0104 chemical sciences ,Chemical engineering ,Optical tweezers ,Ionic strength ,Polymer chemistry ,Materials Chemistry ,Wetting ,0210 nano-technology - Abstract
Surface grafting of polyelectrolytes on materials brings about various significant changes in surface properties such as wettability, adhesion, and friction, because of their excellent hydrophilicity and unique intermolecular interactions that depend on the ionic strength of the solution. This review paper describes the characterization of the swollen structure and electrostatic interaction of polyelectrolyte brushes in aqueous solution by use of optical tweezers and neutron reflectivity, in order to discuss the dissociation of ionic groups and charge distribution in the polyelectrolyte brush. In addition, the spreading and structure of water on the polyelectrolyte brush surface were characterized by high spatial resolution IR spectroscopy.
- Published
- 2016
- Full Text
- View/download PDF
42. Direct Characterization of In-Plane Phase Separation in Polystyrene Brush/Cyclohexane System
- Author
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Hiroshi Jinnai, Atsushi Takahara, Yuki Norizoe, Yuji Higaki, and Daiki Murakami
- Subjects
Binodal ,Materials science ,Polymers and Plastics ,Cyclohexane ,Organic Chemistry ,Lipid microdomain ,Analytical chemistry ,Substrate (chemistry) ,Brush ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Upper critical solution temperature ,law ,Phase (matter) ,Polymer chemistry ,Materials Chemistry ,Polystyrene ,0210 nano-technology - Abstract
The phase behavior of polystyrene (PS) brushes in cyclohexane (CHX) was investigated, for the first time, by environmental atomic force microscopy as a function of the graft density and temperature. The polystyrene brushes of three different graft densities exhibited island-, bicontinuous-, and hole-shape microdomains in the direction parallel to the substrate. The size of such “in-plane” microdomains is close to the end-to-end distance of PS brush chain due to the anchoring of one of the chain ends of PS brushes to the substrate. The microdomain structure disappeared as the temperature increased, and new structure with same morphological features reappeared by lowering temperature. This reversible temperature response corresponds to the in-plane phase separation of the PS brush/CHX system. The UCST type binodal line shifted toward slightly lower temperature in the PS brush/CHX system compared to that of the corresponding nongrafted polymer solution, i.e., PS/CHX system, in excellent agreement with our pr...
- Published
- 2016
- Full Text
- View/download PDF
43. Multipod structures of lamellae-forming diblock copolymers in three-dimensional confinement spaces: Experimental observation and computer simulation
- Author
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Andrei Zvelindovsky, Hiroshi Jinnai, Marco Pinna, Hiroshi Yabu, and Takeshi Higuchi
- Subjects
Materials science ,Polymers and Plastics ,Transmission Electron Microtomography ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Block (periodic table) ,01 natural sciences ,0104 chemical sciences ,law.invention ,Solvent ,Crystallography ,Electron tomography ,Chemical engineering ,law ,Materials Chemistry ,Copolymer ,Particle ,Physical and Theoretical Chemistry ,Electron microscope ,0210 nano-technology - Abstract
The three-dimensional (3D) confinement effect on the microphase-separated structure of a diblock copolymer was investigated both experimentally and computationally. Block copolymer nanoparticles were prepared by adding a poor solvent into a block copolymer solution and subsequently evaporating the good solvent. The 3D structures of the nanoparticles were quantitatively determined with transmission electron microtomography (TEMT). TEMT observations revealed that various complex structures, including tennis-ball, mushroom-like, and multipod structures, were formed in the 3D confinement. Detailed structural analysis, showed that one block of the diblock copolymer slightly prefers to segregate into the particle surface compared with the other block. The observed structures were further elaborated using cell dynamics computer simulation
- Published
- 2016
- Full Text
- View/download PDF
44. Interface manipulated two-phase nanostructure in a triblock terpolymer with a short middle segment
- Author
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Atsushi Takahara, Christopher K. Ober, Rina Maeda, Kenta Okuhara, Teruaki Hayakawa, Takeshi Higuchi, Hiroshi Jinnai, and Ryohei Kikuchi
- Subjects
chemistry.chemical_classification ,Materials science ,Nanostructure ,Polymers and Plastics ,Small-angle X-ray scattering ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Methacrylate ,01 natural sciences ,Polymer engineering ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Polystyrene ,Methyl methacrylate ,0210 nano-technology - Abstract
Interface manipulation to pursue unusual nanostructures was performed using a strategically designed triblock terpolymer with a short middle segment, poly(styrene-b-methyl methacrylate-b-2,2,2-trifluoroethyl methacrylate). A short middle segment of poly(methyl methacrylate) (PMMA) that does not form any distinct domains was found to play an important role in manipulating the interface between the polystyrene (PS) and poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) domains and forming unconventional partially continuous oblate cylinders with an oblique lattice, as confirmed by small angle X-ray scattering (SAXS) and dual-axis transmission electron microtomography (TEMT). Interface manipulation to pursue unusual nanostructures was performed using a strategically designed triblock terpolymer with a short middle segment, poly(styrene-b-methyl methacrylate-b-2,2,2-trifluoroethyl methacrylate). A short middle segment of poly(methyl methacrylate) (PMMA) that does not form any distinct domains was found to play an important role in manipulating the interface between the polystyrene (PS) and poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) domains and forming unconventional partially continuous oblate cylinders with an oblique lattice, as confirmed by small angle X-ray scattering (SAXS) and dual-axis transmission electron microtomography (TEMT).
- Published
- 2016
- Full Text
- View/download PDF
45. Controlled incorporation behavior of gold nanoparticles into ABC triblock terpolymer with double-helical morphology
- Author
-
Hiroshi Yabu, Takeshi Higuchi, Hidekazu Sugimori, and Hiroshi Jinnai
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Nanoparticle ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Polymer engineering ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Colloidal gold ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Polystyrene ,Functional polymers ,Methyl methacrylate ,0210 nano-technology - Abstract
We demonstrated the controlled incorporation of Au nanoparticle grafted with polystyrene (PS) molecules in the helical microdomains of ABC-type linear triblock terpolymers composed of PS, polyisoprene (PI) and poly(methyl methacrylate) (PMMA). The Au nanoparticles grafted with three PSs with different molecular weights were synthesized and incorporated into the terpolymer films. The morphologies of composite films and localization of Au nanoparticles were three-dimensionally characterized with transmission electron microtomography observation. By varying the molecular weights of grafted PS molecules on Au nanoparticles, their assemblies were successfully controlled in the double-helical microdomains.
- Published
- 2016
- Full Text
- View/download PDF
46. Silver Nanoparticle Arrays Prepared by In Situ Automatic Reduction of Silver Ions in Mussel-Inspired Block Copolymer Films
- Author
-
Shusaku Nagano, Hiroshi Yabu, Yasutaka Matsuo, Hiroshi Jinnai, Takeshi Higuchi, Yuta Saito, and Mitsuo Hara
- Subjects
In situ ,Catechol ,Materials science ,Polymers and Plastics ,Organic Chemistry ,02 engineering and technology ,Mussel inspired ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Silver nanoparticle ,0104 chemical sciences ,Ion ,Reduction (complexity) ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Physical and Theoretical Chemistry ,0210 nano-technology - Published
- 2016
- Full Text
- View/download PDF
47. STUDY ON EVALUATION OF CARBONATION RATE OF CONCRETES WITH FINISHING MATERIALS BASED ON NON-DESTRUCTIVE AIR PERMEABILITY TEST
- Author
-
Kiwamu Niwano, Chiduru Kiyohara, Hiroshi Jinnai, and Keiichi Imamoto
- Subjects
Materials science ,Waste management ,Carbonation ,Non destructive ,Air permeability specific surface ,Architecture ,Building and Construction - Published
- 2016
- Full Text
- View/download PDF
48. INFLUENCE OF COARSE AGGREGATE ON STRENGTH CORRECTION VALUE OF CONCRETE IN STRUCTURE FOR HIGH STERENGTH CONCRETE WITH USING SILICA FUME
- Author
-
Hiroshi Jinnai, Satoshi Watanabe, Shusuke Kuroiwa, and Satoru Namiki
- Subjects
Materials science ,Aggregate (composite) ,Silica fume ,Architecture ,Structure (category theory) ,Building and Construction ,Composite material ,Value (mathematics) - Published
- 2016
- Full Text
- View/download PDF
49. QUANTITATIVE STUDY ON CARBONATION PROGRESS OF CONCRETE USING FLY ASH
- Author
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Takumi Zaitsu, Hisashi Sugiyama, Toshimitsu Kobayashi, and Hiroshi Jinnai
- Subjects
010302 applied physics ,Materials science ,Waste management ,Carbonation ,02 engineering and technology ,Building and Construction ,021001 nanoscience & nanotechnology ,01 natural sciences ,Compressive strength ,Fly ash ,0103 physical sciences ,Architecture ,Pozzolanic reaction ,0210 nano-technology - Published
- 2016
- Full Text
- View/download PDF
50. Staining-free observation of polymer blend thin films on transmission extreme ultraviolet microscopy
- Author
-
Jun Chen, Toshiyuki Kakudate, Shiori Gondai, Mitsunori Toyoda, Shunsuke Aizawa, Hiroshi Jinnai, and Masaki Ageishi
- Subjects
Water window ,Soft x ray ,Materials science ,Transmission (telecommunications) ,Extreme ultraviolet ,Microscopy ,General Engineering ,General Physics and Astronomy ,Polymer blend ,Thin film ,Composite material ,Staining - Abstract
Transmission extreme ultraviolet microscopy is applied to the staining-free observation of a poly(styrene–methyl methacrylate) (PS/PMMA) blend. At a photon energy of 92 eV, the imaginary part of the atomic scattering factor for oxygen, which represents the absorption, is four-times larger than that of carbon, and microstructures can be visualized by the contrast resulting from the presence of oxygen. Based on the signal to noise ratio of the images, we consider the optimum photon energy and sample thickness for common polymer blends. Finally, a practical high contrast of 30% is successfully demonstrated for the PS/PMMA thin film.
- Published
- 2020
- Full Text
- View/download PDF
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