Universal access to water-compatible and nanostructured materials via the self-assembly of cationic alternating copolymers

Sujita, Ryota*; Aoki, Hiroyuki; Takenaka, Mikihito*; Ouchi, Makoto*; Terashima, Takaya*

ACS Macro Letters (Internet), 13(6), p.747 - 753, 2024/06

https://doi.org/10.1021/acsmacrolett.4c00173

Interpenetration of rubber and silane coupling agent on an inorganic substrate revealed by spin-contrast-variation neutron reflectivity

Kumada, Takayuki; Iwahara, Daisuke*; Nishitsuji, Shotaro*; Akutsu, Kazuhiro*; Miura, Daisuke; Motokawa, Ryuhei; Sugita, Tsuyoshi; Torikai, Naoya*; Amino, Naoya*; Oku, Takayuki; et al.

Journal of Physical Chemistry C, 128(21), p.8797 - 8802, 2024/05

https://doi.org/10.1021/acs.jpcc.4c00963

We elucidated the entanglement of polybutadiene and silane coupling agent (SCA) molecules bound to Si substrates using spin-contrast-variation (SCV) neutron reflectivity (NR). In an annealed integral blend film of polybutadiene and SCA, a SCA layer generated on the Si substrate was composed of 70 vol. percent SCA molecules extended perpendicularly from the silicon substrate and entangled with 30 vol. percent polybutadiene molecules. By contrast, in an SCA-precoated polybutadiene film, the SCA-precoated layer is composed of densely packed SCA molecules forming crystal-like structure, and thus did not become entangled with the postcoated polybutadiene molecules. This poor entanglement resulted in poor binding between polybutadiene and Si substrate.

Neutron reflectivity study on the nanostructure of PMMA chains near substrate interfaces based on contrast variation accompanied with small molecule sorption

Shimokita, Keisuke*; Yamamoto, Katsuhiro*; Miyata, Noboru*; Nakanishi, Yohei*; Shibata, Motoki*; Takenaka, Mikihito*; Yamada, Norifumi*; Seto, Hideki*; Aoki, Hiroyuki; Miyazaki, Tsukasa*

Soft Matter, 19(11), p.2082 - 2089, 2023/03

https://doi.org/10.1039/D2SM01482C

Water-assisted microphase separation of cationic random copolymers into sub-5 nm lamellar materials and thin films

Imai, Sahori*; Arakawa, Masato*; Nakanishi, Yohei*; Takenaka, Mikihito*; Aoki, Hiroyuki; Ouchi, Makoto*; Terashima, Takaya*

Macromolecules, 55(20), p.9113 - 9125, 2022/10

https://doi.org/10.1021/acs.macromol.2c01287

Neutron reflectometry tomography for imaging and depth structure analysis of thin films with in-plane inhomogeneity

Aoki, Hiroyuki; Ogawa, Hiroki*; Takenaka, Mikihito*

Langmuir, 37(1), p.196 - 203, 2021/01

https://doi.org/10.1021/acs.langmuir.0c02744

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Cylindrical domains of block copolymers developed via ordering under moving temperature gradient

Mita, Kazuki*; Tanaka, Hirokazu*; Saijo, Kenji*; Takenaka, Mikihito*; Hashimoto, Takeji

Macromolecules, 40(16), p.5923 - 5933, 2007/08

https://doi.org/10.1021/ma070404c

A zone heating method, which imposes the moving temperature-gradient field on order in process of various melts in general, enabled to control a macroscopic orientation of microdomain structures in block copolymer bulk. We applied the method to a polystyrene-block-polyisoprene diblock copolymer forming hexagonally packed cylindrical domains (hex-cyl) in the absence of extermal fields. We discovered that the method creates the following special texture of hex-cyl; (1) The texture seemingly consists of volume-filled columnar grains with the grain axis parallel to the temperature gradient axis (defined as the oz axis). (2) The cylinder axis always orients perpendicular to the oz axis with a rotational angle of the cylinder axis around the oz axis being fixed within a grain.

Effects of shear flow on a semidilute polymer solution under phase-separating condition

Endo, Maya*; Takenaka, Mikihito*; Hashimoto, Takeji

Polymer, 47(20), p.7271 - 7281, 2006/09

https://doi.org/10.1016/j.polymer.2006.05.075

We studied the effects of a step-up shear flow from zero shear rate to the given shear rate on formation of shear-induced structures for a semidilute polystyrene (PS)/diethyl malonate (DEM) solution below its could point temperature where the solution undergoes phase separation via spinodal decomposition (SD) in quiescent state.

Small-angle neutron scattering as a useful tool for green innovation materials

Yamaguchi, Daisuke; Noda, Yohei; Koizumi, Satoshi*; Yuasa, Takeshi*; Sone, Takuo*; Tominaga, Tetsuo*; Takenaka, Mikihito*; Amino, Naoya*

no journal, , 

Using a combined ultra-small-angle and small-angle scattering methods with both of neutron and X-ray probes, we characterized hierarchical structures of silica and/or carbon black filler particles dispersed in solution polymerized poly(styrene-random-butadiene) rubber (SBR). Two types of SBR were employed for the preparation of filler/rubber compounds; one possesses a newly developed functionalized chain-end (f-SBR), which has an affinity for filler particles and the other is a conventional SBR (n-SBR) without any special interaction with fillers. Combined small-angle scattering measurements clarified that the average-size of aggregated fillers dispersed in f-SBR matrix is smaller than that dispersed in n-SBR matrix.