| POLYMERS Vol.66 No.8 |
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COVER STORY
Cutting-Edge Science and Technology of Polymer Characterization with Big Facilities |
| COVER STORY: Highlight Reviews |
| Polymer Research with Neutron Scattering | Mitsuhiro SHIBAYAMA |
| <Abstract> It has passed a quarter century since General-User-Program (GRP) of neutron scattering at JRR-3 and a decade since the first neutron beam of J-PARC. Neutron scattering is now a common tool for investigations of polymer structures/dynamics. Since the beginning of the 1990s, neutron scattering users increased rapidly owing to GRP run by Univ. Tokyo. In particular, the small-angle neutron scattering instrument, SANS-U, has been the most frequently used instrument, and more than 30 papers were published per year before the Great Earthquake hit East Japan in March 2011. Today, J-PARC MLF (Materials and Life Science Laboratory) is the only neutron facility available in Japan. J-PARC MLF has 23 neutron beam lines and 19 of them are now running. For polymer science, TAIKAN (BL15) (small angle scattering) and SOFIA (BL16) (neutron reflectivity) are the most commonly used instruments. Several highlighted works carried out at JRR-3, MLF, and foreign facilities are demonstrated in this paper. The history of neutron scattering science in Japan is reviewed followed by comments on future directions. Keywords: Neutron Scattering / JRR-3 / J-PARC MLF / General-User-Program / SANS-U / TAIKAN / SOFIA |
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| Advanced Small-Angle Neutron Scattering at High Intenisty Proton Accelarater | Satoshi KOIZUMI, Yohei NODA |
| <Abstract> Small-angle neutron scattering, using time-of-flight & pulse neutron at Japan proton accelerator research complex (J-PARC), can instantly observe a multi-length scales from a microscopic of the atom size to mesoscopic length scales. We advertize “dynamic nuclear spin polarization contrast variation” as an analysis technique of “the product itself”. Keywords: Small-Angle Neutron Scattering / Pulse Neutron / Time-of-Flight / Dynamic Nuclear Spin Polarization / Contrast Variation |
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| Polymer Characterizations by Unique Methods of Synchrotron SAXS | Isamu AKIBA |
| <Abstract> Firstly, essential methods for structural analyses of polymer materials by using synchrotron small-angle X-ray scattering (SAXS) are briefly summarized. And then, X-ray photon correlation spectroscopy (XPCS) and anomalous small-angle scattering (ASAXS) as relatively novel methods for polymer characterization by using synchrotron SAXS are introduced. Here, the usefulness of XPCS and ASAXS for understanding properties of polymer materials, such as rubber, polymer composites, and drug delivery system, are explained. Finally, the author elaborates on the outlook of future works of synchrotron SAXS by using highly coherent beam, such as free-electron X-ray laser in SACLA, for XPCS and soft/tender X-ray for ASAXS. Keywords: Synchrotron Radiation / Small-Angle X-Ray Scattering / X-Ray Photon Correlation Spectroscopy / Anomalous Small-Angle X-Ray Scattering / Tender X-Ray / Soft-X-Ray |
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| COVER STORY: Topics and Products |
| Long Period Structures in Polymer Liquid Crystals Investigated using Synchrotron Radiation X-Ray Scattering | Masatoshi TOKITA |
| <Abstract> Long period structures in smectic LCs of PB-n polyesters were investigated using synchrotron radiation X-ray scattering. The PB-10 polyesters formed smectic I (SmI) LCs that consisted of 40-nm-thick lamellae stacked along the polymer chain direction. Although the LC lamella thickness (d LC) was largely independent of the degree of polymerization (DP), the isotropization temperature (T i) of the SmI LCs decreased by 12℃ with decreasing the DP. It is explainable if polymer chain ends are included in the lamellae. In the equimolar copolyester of PB-8 and PB-12, d LC was as large as 100 nm, comparable to the chain contour length, indicating the formation of extended chain lamellae. In the copolymer smectic LC, the smectic layer order decreased due to the dissimilarity of the comonomer lengths while the hexagonal order in the lateral packing of the chains was sustained. Keywords: Smectic Liquid Crystal / Main-Chain Liquid Crystal Polymer / Lamella / Long Period / Synchrotoron Radiation / Small Angle X-Ray Scattering |
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| Utilization of SPring-8 BL03XU for Corporate R&D | Mitsunori ASADA |
| <Abstract> Corporate R&D rooted in a principle of polymer structure formation is increasingly important, and the level of demands for structural analysis technologies and problem solving ability becomes higher. We have been actively considering the application of the advanced X-ray scattering/diffraction methods at the large synchrotron radiation facility SPring-8 already for some times to differentiate and improve our corporate R&D abilities. In particular, we have designed equipment and systems for performing in-situ observations with high precision, in order to reproduce a state that is nearly identical to actual polymer production and processing process. So far, we have evaluated varieties of polymer processing such as stretching of polyvinyl alcohol films in water, drawing of polyvinyl alcohol fibers, cast film formation of polyvinyl alcohol aqueous solutions, thermoforming of highly heat resistant polyamides and thermosetting of acrylic block copolymer/epoxy blends. Keywords: SAXS/WAXD / In Situ Observation / Morphology / FSBL |
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| Structural Analysis of Organic Semiconductor Thin Films by GIWAXD | Jun-ichiro KOIKE |
| <Abstract> DIC is interested in the novel technology of printed electronics (PE) based on the wet process. As the new materials of next-generation electronic devices, organic semiconductor (OSC) film is attracting attention in terms of flexibility and so on. The structural understanding of OSC thin film in an actual environment is more important to the development of high-performance TFT using PE technology. Currently, we belong to the FSBL (Advanced Softmaterials Beamline) Consortium, and are able to utilize the synchrotron radiation (SR) X-ray at BL03XU of SPring-8. Here, we show the structural analysis for OSC thin films of benzothiophene type compounds, and show some practical examples of GIWAXD measurements by taking advantage of the SR X-ray characteristics. As the result of time dependent GIWAXD measurement in a drying process, it was found that molecular arrangement of out-of-plane direction fixed later than that of in-plane. In addition, the measurement of OSC thin films on the narrow electrode spacing of TFT was achieved by using a narrow SR X-ray beam. Keywords: Organic Semiconductor / Thin Film / Crystalline Structure / X-Ray Diffraction / Synchrotron Radiation X-Ray / SPring-8 / GIWAXD |
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| Polymer Science and I: A Personal Account |
| Going Forward and Turning | Takahiro MURAOKA |
| <Abstract> In my research carrier, I experienced synthetic, supramolecular and biorelated chemistry as a process of going forward and turning in a walk. On the basis of these experiences, I am trying to open up a new road to an original research in my future. |
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| Front-Line Polymer Science |
| New Strategy for Polymer Brush | Hideaki YOKOYAMA |
| <Abstract> Polymer brush has been attracting interests from scientists and engineers for an effective surface modification method. The development of precise synthesis increased the available polymer spices for polymer brush. Polymer brush has been studied experimentally as well as theoretically. Polymer brush can be characterized with two physical parameters, height and density of brush. Theory predicts extended polymer chains with increasing brush density. The height becomes proportional to the number of segments in brushes. It is increasingly important to measure height and density of brush to understand its property. However, there are only a limited number of experimental tools available for measuring such parameters. Neutron reflectivity is one of few methods for such analysis. In addition to the traditional brush system, the new method to fabricate polymer brush using surface/interface segregation of amphiphilic block copolymer has emerged. In order to partition an amphiphilic diblock copolymer at air surface, the amphiphilic block copolymer must have unique surface activity. Several examples of such air surface segregating system are presented. In addition, segregation of amphiphilic block copolymers from elastomer matrix to water interface was also used to form polymer brush in water. Such system can be called “dynamic polymer brush”, in which self-repairing of brush is expected. Keywords: Polymer Brush / Block Copolymer / Segregation / Interface / Dynamic Polymer Brush / Self-Repairing |
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