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Li K, Matsuba G. Effects of relaxation time and zero shear viscosity on structural evolution of linear low-density polyethylene in shear flow. J Appl Polym Sci 2018. [DOI: 10.1002/app.46053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Nyuui T, Matsuba G, Sato S, Nagai K, Fujimori A. Correlation between gas transport properties and the morphology/dynamics of crystalline fluorinated copolymer membranes. J Appl Polym Sci 2018. [DOI: 10.1002/app.45665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Nie Y, Zhao Y, Matsuba G, Hu W. Shish-Kebab Crystallites Initiated by Shear Fracture in Bulk Polymers. Macromolecules 2018. [DOI: 10.1021/acs.macromol.7b02357] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ohisa S, Pu YJ, Yamada NL, Matsuba G, Kido J. Influence of solution- and thermal-annealing processes on the sub-nanometer-ordered organic-organic interface structure of organic light-emitting devices. NANOSCALE 2017; 9:25-30. [PMID: 27808316 DOI: 10.1039/c6nr06654b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Solution- and thermal-annealing processed organic-organic interface structures were investigated by neutron reflectometry. We revealed the true picture of interfaces, a polymer hole-transporting layer - a small molecule light-emitting layer - a small molecule electron-transporting layer, and discussed influences of those interface structures on organic light-emitting devices.
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Henmi K, Sato H, Matsuba G, Tsuji H, Nishida K, Kanaya T, Toyohara K, Oda A, Endou K. Isothermal Crystallization Process of Poly(l-lactic acid)/Poly(d-lactic acid) Blends after Rapid Cooling from the Melt. ACS OMEGA 2016; 1:476-482. [PMID: 31457140 PMCID: PMC6640745 DOI: 10.1021/acsomega.6b00098] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 09/09/2016] [Indexed: 06/10/2023]
Abstract
We observed the crystallization process in poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) blends using in situ simultaneous small- and wide-angle X-ray scattering measurements with a high-speed temperature control cell. In situ X-ray scattering measurements revealed that density fluctuations larger than the long spacing periods grew during crystallization above 130 °C. In particular, the time evolution of the density fluctuations has a strong dependence on the crystallization temperature. The density fluctuations will promote the crystal nucleation and growth processes of the stereocomplex and increase with increasing crystallization temperature, which is strongly correlated with the complexation of PLLA and PDLA chains. On the other hand, below 120 °C, the kinetics of stereocomplex formation might be hindered by the decreased mobility, and no density fluctuations were observed in the case of homo crystal growth of PLLA or PDLA.
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Ohisa S, Pu YJ, Yamada NL, Matsuba G, Kido J. Molecular Interdiffusion between Stacked Layers by Solution and Thermal Annealing Processes in Organic Light Emitting Devices. ACS APPLIED MATERIALS & INTERFACES 2015; 7:20779-20785. [PMID: 26331696 DOI: 10.1021/acsami.5b05818] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In organic light emitting devices (OLEDs), interfacial structures between multilayers have large impacts on the characteristics of OLEDs. Herein, we succeeded in revealing the interdiffusion in solution processed and thermal annealed OLEDs by neutron reflectometry. We investigated interfaces between a polymer under layer and small molecules upper layer. The small molecules diffused into the swollen polymer layer during the interfacial formation by the solution process, but the polymer did not diffuse into the small molecules layer. At temperatures close to the glass transition temperatures of the materials, asymmetric molecular diffusion was observed. We elucidated the effects of the interdiffusion on the characteristics of OLEDs. Partially mixing the interface improved the current efficiencies due to suppressed triplet-polaron quenching at the interface. Controlling and understanding the interfacial structures of the miultilayers will be more important to improve the OLED characteristics.
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Sato S, Nyuui T, Matsuba G, Nagai K. Correlation between interlamellar amorphous structure and gas permeability in poly(lactic acid) films. J Appl Polym Sci 2014. [DOI: 10.1002/app.40626] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Hemmi K, Matsuba G, Tsuji H, Kawai T, Kanaya T, Toyohara K, Oda A, Endou K. Precursors in stereo-complex crystals of poly(L-lactic acid)/poly(D-lactic acid) blends under shear flow. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576713031907] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
To improve the mechanical and the thermal performance of poly(lactic acid) materials, this work focuses on the formation of stereo-complex crystals by blending poly(L-lactic acid) (PLLA) with poly(D-lactic acid) (PDLA). The resulting structure was analyzed using time-resolvedin situX-ray scattering, optical microscopy, differential scanning calorimetry and viscoelastic measurements. The objective of this study is to investigate the effect of shear flow imposed prior to crystallization on higher-order structure formation and acceleration of stereo-complex crystal growth of PLLA and PDLA blends using a wide spatial scale analysis and viscoelastic measurements. Density fluctuations of 100 nm scale were observed prior to nucleation byin situsimultaneous wide- and small-angle X-ray scattering measurements. These density fluctuations grew with time and the intensity increased with increasing shear rate. Furthermore, the results revealed that the PLLA and PDLA chains were only partially interpenetrated; consequently, stereo-complex crystals could grow only in the mixed PLLA/PDLA phase. The correlation length of density fluctuation prior to nucleation was strongly dependent on the mixed phases.
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Matsui I, Hamano T, Mikami S, Inoue K, Shimomura A, Nagasawa Y, Michigami T, Ohnishi T, Fujii N, Nakano C, Kusunoki Y, Kitamura H, Iwatani H, Takabatake Y, Kaimori JY, Matsuba G, Okoshi K, Kimura-Suda H, Tsubakihara Y, Rakugi H, Isaka Y. Retention of fetuin-A in renal tubular lumen protects the kidney from nephrocalcinosis in rats. Am J Physiol Renal Physiol 2013; 304:F751-60. [PMID: 23344571 DOI: 10.1152/ajprenal.00329.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The serum glycoprotein fetuin-A is an important inhibitor of extraosseous calcification. The importance of fetuin-A has been confirmed in fetuin-A null mice, which develop widespread extraosseous calcification including the kidney. However, the mechanism how fetuin-A protects kidneys from nephrocalcinosis remains uncertain. Here, we demonstrate that intratubular fetuin-A plays a role in the prevention of nephrocalcinosis in the proximal tubules. Although normal rat kidney did not express mRNA for fetuin-A, we found punctate immunohistochemical staining of fetuin-A mainly in the S1 segment of the proximal tubules. The staining pattern suggested that fetuin-A passed through the slit diaphragm, traveled in the proximal tubular lumen, and was introduced into proximal tubular cells by megalin-mediated endocytosis. To test this hypothesis, we inhibited the function of megalin by intravenous injection of histidine-tagged soluble receptor-associated protein (His-sRAP), a megalin inhibitor. His-sRAP injection diminished fetuin-A staining in the proximal tubules and led to urinary excretion of fetuin-A. We further analyzed the role of fetuin-A in nephrocalcinosis. Continuous injection of parathyroid hormone (PTH) 1-34 induced nephrocalcinosis mainly in the proximal tubules in rats. His-sRAP retained fetuin-A in renal tubular lumen and thereby protected the kidneys of PTH-treated rats from calcification. Our findings suggest that tubular luminal fetuin-A works as a natural inhibitor against calcification in the proximal tubules under PTH-loaded condition.
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Zhao Y, Hayasaka K, Matsuba G, Ito H. In Situ Observations of Flow-Induced Precursors during Shear Flow. Macromolecules 2012. [DOI: 10.1021/ma301888r] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zhao Y, Matsuba G, Moriwaki T, Ikemoto Y, Ito H. Shear-induced conformational fluctuations of polystyrene probed by 2D infrared microspectroscopy. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.08.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Deng C, Fujiwara T, Polec I, Matsuba G, Jin L, Inoue R, Nishida K, Kanaya T. Precursor of Shish-Kebab in Atactic Polystyrene/Isotactic Polystyrene Blend above Nominal Melting Temperature. Macromolecules 2012. [DOI: 10.1021/ma300207f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nishida K, Okada K, Asakawa H, Matsuba G, Ito K, Kanaya T, Kaji K. In situ observations of the mesophase formation of isotactic polypropylene—A fast time-resolved X-ray diffraction study. Polym J 2011. [DOI: 10.1038/pj.2011.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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39
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Kawabata J, Matsuba G, Nishida K, Inoue R, Kanaya T. Melt memory effects on recrystallization of polyamide 6 revealed by depolarized light scattering and small-angle X-ray scattering. J Appl Polym Sci 2011. [DOI: 10.1002/app.34294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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40
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Asakawa H, Nishida K, Matsuba G, Kanaya T, Ogawa H. Crystallization of isotactic polypropylene from mesomorphic phase: a constant heating rate study. ACTA ACUST UNITED AC 2011. [DOI: 10.1088/1742-6596/272/1/012024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Igarashi N, Watanabe Y, Shinohara Y, Inoko Y, Matsuba G, Okuda H, Mori T, Ito K. Upgrade of the small angle X-ray scattering beamlines at the Photon Factory. ACTA ACUST UNITED AC 2011. [DOI: 10.1088/1742-6596/272/1/012026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Inoue R, Kawashima K, Matsui K, Kanaya T, Nishida K, Matsuba G, Hino M. Distributions of glass-transition temperature and thermal expansivity in multilayered polystyrene thin films studied by neutron reflectivity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:021801. [PMID: 21405853 DOI: 10.1103/physreve.83.021801] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Indexed: 05/26/2023]
Abstract
We performed neutron reflectivity measurements on multilayered polymer thin films consisting of alternatively stacked deuterated polystyrene (d-PS) and hydrogenated polystyrene (h-PS) layers ∼200 Å thick as a function of temperature covering the glass-transition temperature T(g), and we found a wide distribution of T(g) as well as a distribution of the thermal expansivity α within the thin films, implying the dynamic heterogeneity of the thin films along the depth direction. The reported anomalous film thickness dependences of T(g) and α were reasonably understood in terms of the distributions, showing that the surface mobile layer and the bottom hard interfacial layer are, respectively, responsible for the depressions of T(g) and α with decreasing film thickness. The molecular mobility in each layer is also discussed in relation to the distribution of T(g), based on the results on mutual diffusion at the layer interface.
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Zhao Y, Matsuba G, Nishida K, Fujiwara T, Inoue R, Polec I, Deng C, Kanaya T. Relaxation of shish-kebab precursor in isotactic polystyrene after short-term shear flow. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/polb.22176] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Kawashima K, Inoue R, Kanaya T, Matsuba G, Nishida K, Hino M. Distribution of glass transition temperatureTgin a polymer thin film by neutron reflectivity. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/184/1/012004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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45
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Rahman N, Kawai T, Matsuba G, Nishida K, Kanaya T, Watanabe H, Okamoto H, Kato M, Usuki A, Matsuda M, Nakajima K, Honma N. Effect of Polylactide Stereocomplex on the Crystallization Behavior of Poly(l-lactic acid). Macromolecules 2009. [DOI: 10.1021/ma900004d] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Kubo JI, Rahman N, Takahashi N, Kawai T, Matsuba G, Nishida K, Kanaya T, Yamamoto M. Improvement of poly(vinyl alcohol) properties by the addition of magnesium nitrate. J Appl Polym Sci 2009. [DOI: 10.1002/app.29561] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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47
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Hayashi Y, Matsuba G, Zhao Y, Nishida K, Kanaya T. Precursor of shish–kebab in isotactic polystyrene under shear flow. POLYMER 2009. [DOI: 10.1016/j.polymer.2009.03.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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48
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Ogawa H, Kanaya T, Nishida K, Matsuba G, Majewski JP, Watkins E. Time-resolved specular and off-specular neutron reflectivity measurements on deuterated polystyrene and poly(vinyl methyl ether) blend thin films during dewetting process. J Chem Phys 2009. [DOI: 10.1063/1.3224125] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Nishida K, Ogawa H, Matsuba G, Konishi T, Kanaya T. A high-resolution small-angle light scattering instrument for soft matter studies. J Appl Crystallogr 2008. [DOI: 10.1107/s002188980801265x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A small-angle light scattering (SALS) instrument with a high resolution at low angles and a high signal-to-noise ratio has been developed. Both a wide dynamic range and a wide scattering vector range are achieved using a two-dimensional array of complementary metal oxide semiconductor image sensors. These instrument characteristics have enabled us to obtain high-quality light scattering data from soft matter systems. This setup is especially well suited to studies of systems with a weak scattering power and/or a time-dependent structure evolution in a wide spatial range from submicrometre to submillimetre. An application of this instrument to a polyelectrolyte blend and an extremely thin blend film are reported.
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Ogawa H, Kanaya T, Nshida K, Matsuba G. Composition fluctuations before dewetting in polystyrene/poly(vinyl methyl ether) blend thin films. POLYMER 2008. [DOI: 10.1016/j.polymer.2008.03.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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