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Volume 87, Issue 6
Displaying 1-11 of 11 articles from this issue
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Special Issue for General Reviews “Innovative materials by biomimetic and self-assembly approach (II)”
Introductory Remarks
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[in Japanese]2014 Volume 87 Issue 6 Pages 211-
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSDownload PDF (108K)
General Reviews
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[in Japanese]2014 Volume 87 Issue 6 Pages 212-
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSDownload PDF (167K) -
Hajime KISHI2014 Volume 87 Issue 6 Pages 213-218
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSEpoxy network polymers are widely used in structural materials, adhesives, paints, and electronics materials. Several modifiers, such as rubbers, fillers, and thermoplastic polymers, were blended to improve the fracture toughness of the cured epoxy polymers, as well as the investigation of new chemical structures of epoxy oligomers and curing agents. Recently, block copolymers having self-assembly ability get attracted attention as modifiers for the toughening of epoxy resins. In this paper, the self-assembly nano-structures of the epoxy polymer blends and the toughening effect are reviewed.View full abstractDownload PDF (1529K) -
Jun MATSUI2014 Volume 87 Issue 6 Pages 219-225
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSThe most efficient electric devices in nature will be the light harvesting system in biological membrane. Photosensitive proteins complex, such as photosystem I (PS I), photosystem II (PS II), and electron transport proteins complex such as cytochrome were hierarchically assembled in the bilayer membrane based on their redox potentials. Electrons, which were produced by photoinduced electron transfer in PS II are unidirectionally transferred to cytochrome b6f then PS I following the potential gradient in the membrane. We can produce similar hierarchical molecular assemblies using the Langmuir-Blodgett (LB) technique. The unidirectional electron current flow has been achieved in hierarchical assembled LB films to produce efficient light-energy conversion devices. In this paper, we prepare hierarchical assembled polymer films using the LB technique. It has been reported that poly (N-dodecylacrylamide) forms a stable polymer monolayer “polymer nanosheets” at the air-water interface. Several electrofunctional polymer nanosheets were assembled in a tailor-made manner to achieve the unidirectional electron transfer. We applied the unidirectional electron transfer to produce other unique electrofunctional devices such as molecular memory and mutli-color electrochromism. The results indicate that we can produce unique electric devices by not just mimicking functions in nature but extracting the essence of their functions and applying them.View full abstractDownload PDF (1661K) -
Yukikazu TAKEOKA2014 Volume 87 Issue 6 Pages 226-230
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSIn this review, I introduce the microstructures and optical properties of angle-independent structurally coloured barbs of blue birds, then describe the fabrication and the optical nature of the artificially prepared imitations of such biological systems.View full abstractDownload PDF (1458K) -
Taka-Aki ASOH2014 Volume 87 Issue 6 Pages 231-235
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSThe development of microstructure-regulated three dimensional (3-D) materials has attracted much attention for scaffold in the field of tissue engineering, carrier of drug delivery systems, and soft actuators. For example, living tissues are 3-D matrices with highly organized and stratified architectures. Adhesion of soft materials including hydrogels has therefore attracted attention because it is one of the most important processes for building functional soft constructs. To develop functional and microstructure-regulated devices using hydrogels, the “adhesion” of hydrogels is required. We recently reported a novel strategy for the adhesion of cationic and anionic hydrogels. The adhesion of the hydrogels was achieved via electrophoresis to deliver the polyions inside the gels, and to form a polyion complex at the interface between the two hydrogels for adhesion. The present novel adhesion strategy will be useful not only for the adhesion of gels, but also for the fabrication of novel gel constructs.View full abstractDownload PDF (1015K) -
Tomoaki UCHIYAMA2014 Volume 87 Issue 6 Pages 236-242
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSDurable and reliable fuel cell (FC) stack designs need to be manufactured at low cost for FCs to be widely commercialized. FC consists of many functional layers. Membrane electrode assemblies (MEAs) are located in the center of the FC and are the main component to affect its generating performance. The MEA is a hydrophilic multi-layer membrane that consists of a polymer electrolyte membrane (PEM) and catalyst layers (CLs) that sandwich the PEM. Mechanical properties, the mechanical failure mechanism and the mitigation methods for MEA are summarized in this article. Pinhole formation in PEM induces gas leakage through the PEM and decreases generating performance. The failure mechanism for laminated MEAs and gas diffusion layers (GDLs) must be understood to ensure the reliable design of the MEA. The MEA easily deforms under channel portions of gas flow fields, because contact pressure between the MEA and GDL is relatively low. In-plane buckling deformation of MEA under swelling is an initial stage of mechanical degradation, and crack initiation occurs after the buckling. These failures can be prevented by high contact pressure between the MEA and GDL.View full abstractDownload PDF (890K)
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Asako NAKAJIMA , Makiko ENOKI2014 Volume 87 Issue 6 Pages 243-245
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSA white rot fungus, Ceriporiopsis subvermispora, was shown to be able to depolymerize synthetic cis-1,4-polyisoprene (isoprene rubber; IR) in liquid medium, which was analyzed with size exclusion chromatography (SEC). During the 3-day incubation with C. subvermispora, the weight average molecular weight (Mw) of IR drastically decreased to be 24 % of those for starting IR. According to the SEC profiles, the decrease in Mw seems to occur via random scission of IR main chain. On the other hand, the change of Mw of IR shifted from decreasing to increasing during 3 to 7 days of incubation, and then the shift reversed during 7 to 28 days. This phenomenon appears to be caused by cross-linking among main chains via radical coupling implying that unpaired electrons, radicals, happen on the main chain of IR. From these results, under incubation with C. subvermispora, it is supposed that IR is depolymerized and/or cross linked by free radicals via oxidative radical reaction like lipid peroxidation, i.e., carbon-centered radical (C⋅) happens on the IR chain leading it to chain scission to show reducing Mw, otherwise, two of C⋅ on different IR chains couple to form cross linkage increasing their molecular weight.View full abstractDownload PDF (287K)
Regular Papers
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Eiichi TAKATORI, Yoshinori MATSUMOTO, Takayuki ADACHI, Reiko OKAZAKI2014 Volume 87 Issue 6 Pages 246-251
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSWe observed a relationship between the size of one polystyrene (PS) molecule in a dilute solution and in an extractive or evaporative solid state prepared from a PS dilute solution. In the both cases we observed the scaling relationship between the molecular weight and the molecular size. And the distributions of these sizes were also almost same. Though the scaling exponent was about 0.6 in the dilute solution, the exponent of the mono-molecule solid PS was 0.6 below Mw=7.5×106 and 0.33 above Mw=7.5×106. This was consistent with the experimental result that the ELSD (evaporative light scattering detector) peak area of a PS solution became lower above a critical molecular weight even if the PS mass concentration was same. Above a critical molecular weight the PS mono-molecular solid particle would shrink smaller than the value which was speculated form the size in the dilute solution.View full abstractDownload PDF (1412K)
Advanced Course on Rubber Science and Technology
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2. Visualization of carbon black network in rubber vulcanizates and its relation-ship with electric propertiesAtsushi KATO, Yuko IKEDA2014 Volume 87 Issue 6 Pages 252-258
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL FREE ACCESSAdvantages of 3D-TEM/electron tomography are described for development of rubber science and technology. The first result of visualization of carbon black (CB) network is shown, which was obtained by combining 3D TEM/electron tomography and electric characteristic measurements. A novel analysis for characterization of the CB network is proposed on the basis of gelation mechanism of polymer network, where structural parameters of crosslined and branched chains of CB aggregates are determined by 3D-TEM/electron tomography and are utilized. Good relationships between the CB network structures and electrolytic properties are also shown in this review paper.View full abstractDownload PDF (1231K)
Technical Note
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2014 Volume 87 Issue 6 Pages Annc6_201-
Published: 2014
Released on J-STAGE: January 22, 2015
JOURNAL RESTRICTED ACCESSDownload PDF (240K)
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