Surface and interfacial aggregation states in thin films of a polystyrene/polyrotaxane blend

Taguchi, Miki*; Miyata, Noboru*; Miyazaki, Tsukasa*; Aoki, Hiroyuki; Ozawa, Satoru*; Hasegawa, Ryuichi*; Morimitsu, Yuma*; Kawaguchi, Daisuke*; Yamamoto, Satoru*; Tanaka, Keiji*

Polymer Journal, 7 Pages, 2025/03

https://doi.org/10.1038/s41428-025-01030-y

Synthesis of heat-resistant living polymer particles by one-step reversible addition-fragmentation chain transfer precipitation polymerization of styrene and -phenylmaleimide

Yamazaki, Shun*; Kaneko, Naoya*; Kato, Atsuya*; Watanabe, Kohei*; Aoki, Daisuke*; Taniguchi, Tatsuo*; Karatsu, Takashi*; Ueda, Yuki; Motokawa, Ryuhei; Okura, Koki*; et al.

Polymer, 298, p.126846_1 - 126846_11, 2024/04

https://doi.org/10.1016/j.polymer.2024.126846

Structural changes of polystyrene particles in subcritical and supercritical water revealed by in situ small-angle neutron scattering

Shibata, Motoki*; Nakanishi, Yohei*; Abe, Jun*; Arima, Hiroshi*; Iwase, Hiroki*; Shibayama, Mitsuhiro*; Motokawa, Ryuhei; Kumada, Takayuki; Takata, Shinichi; Yamamoto, Katsuhiro*; et al.

Polymer Journal, 55(11), p.1165 - 1170, 2023/11

https://doi.org/10.1038/s41428-023-00817-1

Microscopic structural changes during the freeze cross-linking reaction in carboxymethyl cellulose nanofiber hydrogels

Miura, Daisuke*; Sekine, Yurina; Nankawa, Takuya; Sugita, Tsuyoshi; Oba, Yojiro; Hiroi, Kosuke; Ozawa, Tatsuhiko

Carbohydrate Polymer Technologies and Applications (Internet), 4, p.100251_1 - 100251_9, 2022/12

https://doi.org/10.1016/j.carpta.2022.100251

The reaction mechanism of carboxymethyl cellulose nanofiber (CMCF) hydrogel formed by freeze-crosslinking was investigated. We succeeded in observing the hierarchical structural changes during the freeze-crosslinking reaction. Freeze-crosslinked CMCF hydrogels exhibited a characteristic hierarchical alignment structure from the angstrom to micrometer scale that differed from normal cross-linked CMCF hydrogels produced by a conventional method without freezing. It was shown that the characteristic hierarchical structure contributes the excellent mechanical properties of freeze-crosslinked CMCF hydrogels.

Structural investigation of sulfonated polyphenylene ionomers for the design of better performing proton-conductive membranes

Shiino, Keisuke*; Otomo, Toshiya; Yamada, Takeshi*; Arima, Hiroshi*; Hiroi, Kosuke; Takata, Shinichi; Miyake, Jumpei*; Miyatake, Kenji*

ACS Applied Polymer Materials (Internet), 2(12), p.5558 - 5565, 2020/11

https://doi.org/10.1021/acsapm.0c00895

Preparation, characterization, and dilute solution properties of four-branched cage-shaped poly(ethylene oxide)

Noda, Takashi*; Doi, Yuya*; Ota, Yutaka*; Takata, Shinichi; Takano, Atsushi*; Matsushita, Yushu*

Journal of Polymer Science, 58(15), p.2098 - 2107, 2020/08

https://doi.org/10.1002/pol.20200286

Phase behavior and Li ion conductivity of styrene-ethylene oxide multiblock copolymer electrolytes

Sarapas, J. M.*; Saijo, Kenji*; Zhao, Y.; Takenaka, Mikihito*; Tew, G. N.*

Polymers for Advanced Technologies, 27(7), p.946 - 954, 2016/07

https://doi.org/10.1002/pat.3753

Molecular dynamics simulation of telomeric single-stranded DNA and POT1

Kaburagi, Masaaki; Yamada, Hironao*; Miyakawa, Takeshi*; Morikawa, Ryota*; Takasu, Masako*; Kato, Takamitsu*; Uesaka, Mitsuru*

Polymer Journal, 48(2), p.189 - 195, 2016/02

AA2015-0476.pdf:1.08MB

https://doi.org/10.1038/pj.2015.82

We performed molecular dynamics (MD) simulations of telomeric single-stranded DNA and POT1 for 100 ns. The distance between (POT1) and O5' (telomeric ssDNA) is calculated to verify the binding system for 100 ns MD. We then calculated the distance between the bases of telomeric DNA ends and the root mean square deviation and gyration radius in single and binding states. We compared the root mean square fluctuations between single and binding states and calculated the number of hydrogen bonds between POT1 and telomeric DNA. There are many hydrogen bonds between Gln94 and the first guanine of the closest TTAGGG sequence in telomeric single-stranded DNA. These Gln94 and the guanine have a large difference in root mean square fluctuation between single and binding states. We found that Gln94 and guanine are important components of the binding system, and they are related to its stability.

Dependence of structure of polymer side chain on water structure in hydrogels

Sekine, Yurina; Takagi, Hajime*; Sudo, Sayoko*; Kajiwara, Yutaro*; Fukazawa, Hiroshi; Fukazawa, Tomoko*

Polymer, 55(24), p.6320 - 6324, 2014/11

https://doi.org/10.1016/j.polymer.2014.10.011

To investigate the effects of structure of polymer side chains on structure of water in hydrogels, Raman spectra of polyacrylamide (PAA) and poly-,-dimethylacrylamide (PDMAA) hydrogels were measured. PAA and PDMAA have similar chemical structures, except for the side chain structure. The result shows that the frequency of the OH stretching mode for the PAA hydrogel decreases as the water content decreases, while that for the PDMAA hydrogel increases. We conclude that most of the bound water molecules in the PAA hydrogel form four strong hydrogen bonds with the hydrophilic groups in the side chain of PAA, whereas those in the PDMAA hydrogel form weak hydrogen bonds with surrounding water molecules. The water structure is an important factor governing the physical and chemical properties of gel materials.

Graft-type polymer electrolyte membranes for fuel cells prepared through radiation-induced graft polymerization into alicyclic polybenzimidazoles

Park, J.*; Takayama, Toshio*; Asano, Masaharu; Maekawa, Yasunari; Kudo, Kazuaki*; Takayama, Toshio*

Polymer, 54(17), p.4570 - 4577, 2013/08

https://doi.org/10.1016/j.polymer.2013.06.042

Graft-type sulfonated polybenzimidazole was prepared through radiation-induced graft polymerization of styrenes into an alicyclic polybenzimidazole film and subsequent sulfonation. The alicyclic polybenzimidazole, ChPBI, was prepared from -1,4-cyclohexanedicarboxylic acid and 3,3'-diaminobenzidine using typical polycondensation. Anisotropic domains with a size of several tens of micrometers were found in the ChPBI films casted from LiCl-containing ,-dimethylacetamide. Irradiation of the ChPBI membranes with a 220 kGy dose of -rays created radical species with mean lifetimes of two days. The treatment of this membrane with a 50/50 (v/v) mixture of 1-propanol and styrene produced polystyrene graft chains. Sulfonation of the resulting grafted membrane with ClSOHOH occurred selectively on the polystyrene grafts. The sulfonated films showed proton conductivity on the order of 10 to 10 S/cm with an ion exchange capacity between 2.1 and 2.9 mmol/g. SEM-EDX analysis of the membrane indicated the presence of macrophase separated domains up to 1 m in diameter. The proton conductivity of the membrane did not decrease for 600 h at 120C in liquid water.