Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Harada, Masashi*; Takata, Shinichi; Iwase, Hiroki*; Kajiya, Shuji*; Kadoura, Hiroaki*; Kanaya, Toshiji*
ACS Omega (Internet), 6(23), p.15257 - 15263, 2021/06
Times Cited Count：22 Percentile：80.11(Chemistry, Multidisciplinary)Ito, Kanae; Harada, Masashi*; Yamada, Norifumi*; Kudo, Kenji*; Aoki, Hiroyuki; Kanaya, Toshiji*
Langmuir, 36(43), p.12830 - 12837, 2020/11
Times Cited Count：14 Percentile：55.74(Chemistry, Multidisciplinary)Miyazaki, Tsukasa*; Miyata, Noboru*; Yoshida, Tessei*; Arima, Hiroshi*; Tsumura, Yoshihiro*; Torikai, Naoya*; Aoki, Hiroyuki; Yamamoto, Katsuhiro*; Kanaya, Toshiji*; Kawaguchi, Daisuke*; et al.
Langmuir, 36(13), p.3415 - 3424, 2020/04
Times Cited Count：17 Percentile：62.71(Chemistry, Multidisciplinary)Miyazaki, Tsukasa*; Miyata, Noboru*; Asada, Mitsunori*; Tsumura, Yoshihiro*; Torikai, Naoya*; Aoki, Hiroyuki; Yamamoto, Katsuhiro*; Kanaya, Toshiji*; Kawaguchi, Daisuke*; Tanaka, Keiji*
Langmuir, 35(34), p.11099 - 11107, 2019/08
Times Cited Count：25 Percentile：69.23(Chemistry, Multidisciplinary)Akutsu, Kazuhiro*; Cagnes, M.*; Tamura, Kazuhisa; Kanaya, Toshiji*; Darwish, T. A.*
Physical Chemistry Chemical Physics, 21(32), p.17512 - 17516, 2019/08
Times Cited Count：11 Percentile：52.67(Chemistry, Physical)We combined the deuterium labeling and neutron reflectivity techniques to determine the fine structure of the electric double layer structure in an imidazolium ionic liquid (IL). For this, a simple and large scale deuteration method for imidazolium ILs was developed, where the deuteration level can be systematically controlled.
Inoue, Rintaro*; Kanaya, Toshiji*; Yamada, Takeshi*; Shibata, Kaoru; Fukao, Koji*
Physical Review E, 97(1), p.012501_1 - 012501_6, 2018/01
Times Cited Count：10 Percentile：63.17(Physics, Fluids & Plasmas)In this study, we investigate the 
process of a polystyrene thin film using inelastic neutron scattering (INS), dielectric relaxation spectroscopy (DRS), and thermal expansion spectroscopy (TES). The DRS and TES measurements exhibited a decrease in glass transition temperature (
) with film thickness. On the other hand, an increase in was observed in INS studies. In order to interpret this contradiction, we investigated the temperature dependence of the peak frequency (
) of the process probed by DRS and TES. The experiments revealed an increase in the peak frequency () with decreasing film thickness in the frequency region. This observation is consistent with the observed decrease in with thickness. The discrepancy between INS and DRS or TES descriptions of the process is likely to be attributed to a decrease in the apparent activation energy with film thickness and reduced mobility, due to the impenetrable wall effect.
Kanaya, Toshiji*; Takahashi, Nobuaki; Takeshita, Hiroki*; Okura, Masatoshi*; Nishida, Koji*; Kaji, Keisuke*
Polymer Journal, 44(1), p.83 - 94, 2012/01
Times Cited Count：32 Percentile：71.42(Polymer Science)Kubo, Junichi*; Rahman, N.*; Takahashi, Nobuaki; Kawai, Takahiko*; Matsuba, Go*; Nishida, Koji*; Kanaya, Toshiji*; Yamamoto, Masahide*
Journal of Applied Polymer Science, 112(3), p.1647 - 1652, 2009/05
Times Cited Count：26 Percentile：63.26(Polymer Science)Aiming at improvement of mechanical and dielectric properties of poly(vinyl alcohol) (PVA) we prepared composites of PVA and magnesium nitrate. It was found that the composites were very soft and rubber-like, and the glass transition temperature decreased with increasing the salt concentration. Wide-angle X-ray diffraction and small-angle X-ray scattering revealed that the crystallites of PVA were destroyed by the additive and it was a cause of the softening.
Fujii, Yasuhiko; Arai, Masatoshi; Kadono, Ryosuke*; Kanaya, Toshiji*; Kamiyama, Takashi*; Niimura, Nobuo*; Nojiri, Hiroyuki*; Noda, Yukio*; Yagi, Takehiko*; Yamada, Kazuyoshi*
Kotai Butsuri, 43(7), p.441 - 450, 2008/07
no abstracts in English
Takahashi, Nobuaki; Kanaya, Toshiji; Nishida, Koji*; Kaji, Keisuke*
Macromolecules, 40(24), p.8750 - 8755, 2007/11
Times Cited Count：17 Percentile：47.23(Polymer Science)Time-resolved light scattering measurements have been performed on poly(vinyl alcohol) (PVA) in mixed solvents of dimethyl sulfoxide (DMSO) and water with various mixing ratios after quenching from 100
C to 25C to examine physical gelation process. A broad scattering peak characteristic to phase separation appeared in the light scattering profiles after a certain incubation time (
) and the peak position 
moved to higher with annealing time. The results contradict the theoretical predictions and experimental observations for usual phase separation systems, suggesting effects of gelation (or network formation) on the phase separation. The growth kinetics significantly depend on the mixing ratio of DMSO and water, showing that the solvent quality is also a factor to affect the phase separation kinetics during the physical gelation process. The unusual phase separation kinetics is discussed in terms of gelation-induced phase separation.
Kanaya, Toshiji; Matsuba, Go*; Ogino, Yoshiko*; Takahashi, Nobuaki; Nishida, Koji*
Polymer Journal, 39(11), p.1085 - 1097, 2007/11
Times Cited Count：0 Percentile：0.00(Polymer Science)One of the longstanding issues in polymer science is crystallization of polymers under flow, especially formation of the so-called shish-kebab. Recent progress in quantum beam technology shed light on the substantial nature in the shish-kebab formation. In this paper we review our recent experiments on polymer crystallization under flow using time-resolved depolarized light scattering, small-angle and wide-angle X-ray scattering and small-angle neutron scattering in a wide spatial scale from 0.1 nm to several tens m. These studies revealed that the shish-kebab formation is governed by a competition between the crystallization rate and the chain relaxation rate.
Takahashi, Nobuaki; Nishida, Koji*; Inoue, Rintaro*; Ogawa, Hiroki*; Kanaya, Toshiji*; Nagao, Michihiro*
NSL News Letter, 2007-4, p.155 - 157, 2007/04
We have studied dynamics of poly(vinyl alcohol) (PVA) gel in a mixture of deuterated dimethyl sulfoxide (DMSO-d
) and D
O (60/40 by volume) during heating process from 25C to 80C using neutron spin-echo (NSE) techniques.
Kanaya, Toshiji*; Takahashi, Nobuaki; Nishida, Koji*; Seto, Hideki*; Nagao, Michihiro*; Takeda, Takayoshi*
Physica B; Condensed Matter, 385-386(1), p.676 - 681, 2006/11
Times Cited Count：13 Percentile：51.32(Physics, Condensed Matter)We report neutron spin-echo measurements on three types of poly(vinyl alcohol) (PVA) gels. The first is PVA gel in a mixture of dimethyl sulfoxide (DMSO) and water with volume ratio 60/40, the second is PVA gel in an aqueous borax solution and the third is chemically cross-linked PVA gel. The observed normalized intermediate scattering functions I(Q,t)/I(Q,0) were very different among them. The I(Q,t)/I(Q,0) of the first and third gels showed a non-decaying component in addition to a decaying component, but the second one did not have the non-decaying one. This clearly indicates that the fluctuations in the first and third PVA gels consist of static and dynamic fluctuations whereas the second PVA gel does include only the dynamic fluctuations. The dynamic and static fluctuations of the PVA gels were analyzed in terms of a restricted motion in the gel network and the Zimm motion, respectively.
Takahashi, Nobuaki; Kanaya, Toshiji*; Nishida, Koji*; Takahashi, Yoshiaki*; Arai, Masatoshi
Physica B; Condensed Matter, 385-386(1), p.810 - 813, 2006/11
Times Cited Count：6 Percentile：30.48(Physics, Condensed Matter)We have studied shear flow effects on physical gelation processes of poly(vinyl alcohol) solutions in a mixture of deuterated dimethyl sulfoxide and heavy water using time-resolved 2D-SANS technique with a rheological setup. Steady shear flow was applied on the sample solution after quenching from 100 C to 25 C, and the isothermal measurements were performed. The observed two-dimensional scattering patterns under the shear flow were isotropic while the growth rate of the scattering intensity was affected. It has been revealed in a previous report that the gelation of the solution was caused through crystallization between polymer chains to form the network. Hence, focusing on the scattering intensity from the crystallites, we have evaluated the crystallization rate. It was found that the crystallization rate was accelerated in a low shear rate region (shear rate is smaller than 5 sec
) and decreased with increasing the shear rate in a high rate region (bigger than 5 sec) after a maximum at 5 sec. The results suggest that the local orientation of flexible polymer chains due to the shear flow assist crystal nucleation in the low shear rate region while the once-formed crystallites are destroyed by the shear in the high shear rate region.
Ogino, Yoshiko*; Fukushima, Hajime*; Takahashi, Nobuaki; Matsuba, Go*; Nishida, Koji*; Kanaya, Toshiji*
Macromolecules, 39(22), p.7617 - 7625, 2006/10
Times Cited Count：78 Percentile：88.71(Polymer Science)We studied crystallization process of isotactic polypropylene (iPP) under shear flow as a function of shear rate using time-resolved wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), depolarized light scattering (DPLS) and polarized optical microscope (POM) to elucidate the formation mechanism of the so-called shish-kebab structure in a wide spatial scale from 0.1 nm to several tens micro-m. In the time-resolved DPLS, SAXS and WAXS measurements we observed the formation processes of the shish-like structure, the kebab structure and the crystalline lattice (mostly in the kebab), respectively, and found that there were critical shear rates for the anisotropic structure formation in the DPLS, SAXS and WAXS measurements. The values are very close each other, suggesting the anisotropic structure formations in both of the shish and the kebab are dominated by a common origin. Furthermore, comparing the onset times of intensities in DPLS, SAXS and WAXS, we found that the onset of DPLS intensity is the most accelerated by the shear among the three. On the basis of the observations, we propose a possible mechanism for the shish-kebab structure.
Takahashi, Nobuaki; Nishida, Koji*; Tsubouchi, Tsuyoshi*; Ogawa, Hiroki*; Inoue, Rintaro*; Kanaya, Toshiji*; Nagao, Michihiro*
ISSP Activity Report on Neutron scattering Research; Experimental Reports (CD-ROM), 13, 2 Pages, 2006/00
no abstracts in English
Kanaya, Toshiji; Takahashi, Nobuaki; Inoue, Rintaro*; Matsuba, Go*; Nishida, Koji*; Nagao, Michihiro*
ISSP Activity Report on Neutron scattering Research; Experimental Reports (CD-ROM), 13, 1 Pages, 2006/00
rangeKanaya, Toshiji*; Kakurai, Kazuhisa; Tsukushi, Itaru*; Inoue, Rintaro*; Watanabe, Hiroshi*; Nishi, Masakazu*; Nakajima, Kenji; Takemura, Kazuhiro*; Furuya, Hidemine*
Journal of the Physical Society of Japan, 74(12), p.3236 - 3240, 2005/12
Times Cited Count：6 Percentile：41.32(Physics, Multidisciplinary)We performed thermal neutron spin echo measurements on a glass-forming polymer, deuterated polybutadiene (-[CD-CD=CD-CD]
-; PB-d), in a high range up to 3.5
covering the first and second peaks of the structure factor S(), and evaluated the decay rate 
() of the coherent intermediate scattering function as a function of . In contrast to the previous experimental findings on the first peak of S() at = 1.5, no "de Gennes" type narrowing was observed on the second peak at = 2.9. This novel finding indicates that the narrowing is hidden by the distinct motions of the soft -CD-CD- and =CD-CD- units and the self-motions of the rigid and soft units in the range around the second peak.
Takahashi, Nobuaki; Kanaya, Toshiji*; Nishida, Koji*; Seto, Hideki*; Nagao, Michihiro*; Takeda, Takayoshi*
no journal, ,
We have extensively studied nano-scale structure and dynamics of three types of poly(vinyl alcohol) (PVA) gels by using small-angle neutron scattering (SANS) and neutron spin-echo (NSE) techniques; two physical gels and one chemical gel. The first one was a PVA gel in a mixture of deuterated dimethyl sulfoxide (DMSO-d6) and D2O with volume fraction of DMSO-d6 being 0.6, in which cross-links were made of crystallites. On the basis of NSE results, SANS intensity was divided into static and dynamic fluctuations to find that the former contribution was dominant in the present wave vector (Q) range. The latter, dynamic fluctuations were analyzed in terms of fluctuations of cross-links in the quasi-equilibrium position. The second gel was PVA in aqueous borax solution. The intermediate scattering functions of the gel as well as the sol were well described by Zimm mode and gel mode in Q regions of above and below a critical wave vector (Qc). The last one was the chemically cross-linked PVA gel. The intermediate scattering function was also described by Zimm mode in a short-time region, suggesting that it behaves like polymer solution. However, in a long-time region, the data points deviated from Zimm-scaled master curve, suggesting that it was restricted by the cross-links made of covalent bonds.
