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431.
Minoru Nagata Tsuyoshi Kiyotsukuri Atsushi Kajita Naoto Tsutsumi Wataru Sakai 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(9):1153-1163
Abstract Nylon 66 (N66) copolymers were prepared by melt polycondensation of adipic acid and hexamethylenediamine with 5–80 mol% poly(ethylene glycol) (PEG), where the molecular weight (MW) of PEG was 200–1000. The reduced specific viscosity of the copolymers was increased by the copolymerization. The crystallinity and melting temperature (T m) of N66 components decreased with increasing PEG content, but T m depression of copolymers at the same mole content decreased with increasing MW of PEG, suggesting that the copolymer structures are not of the random type but of the block type at the higher MW of PEG. The water absorption increased with increasing PEG content, and its increase was much higher at the higher MW of PEG. The enzymatic degradation was estimated by the weight loss of copolymer films in the buffer solution with and without a lipase at 37°C. The weight loss was enhanced appreciably by the presence of a lipase, and increased abruptly at higher PEG content, which was correlated to water absorption and the concentration of ester linkages. The enzymatic degradation of these N66 copolymers was much higher than that of previously reported PET copolymers with PEG. The abrupt increase of weight loss by alkali hydrolysis was fairly comparable to that of water absorption. 相似文献
432.
Wataru Kurashige Yutaro Mori Shuhei Ozaki Masanobu Kawachi Sakiat Hossain Tokuhisa Kawawaki Cameron J. Shearer Akihide Iwase Gregory F. Metha Seiji Yamazoe Akihiko Kudo Yuichi Negishi 《Angewandte Chemie (International ed. in English)》2020,59(18):7076-7082
The activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2?xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2?xCrxO3 particles was decreased further, it is difficult to load ultrafine (<2 nm) Rh2?xCrxO3 particles onto a photocatalyst by using conventional loading methods. In this study, a new loading method was successfully established and was used to load Rh2?xCrxO3 particles with a size of approximately 1.3 nm and a narrow size distribution onto a BaLa4Ti4O15 photocatalyst. The obtained photocatalyst exhibited an apparent quantum yield of 16 %, which is the highest achieved for BaLa4Ti4O15 to date. Thus, the developed loading technique of Rh2?xCrxO3 particles is extremely effective at improving the activity of the water‐splitting photocatalyst BaLa4Ti4O15. This method is expected to be extended to other advanced water‐splitting photocatalysts to achieve higher quantum yields. 相似文献
433.
Equilibrium Shift in Solution: Molecular Shape Recognition and Precipitation of a Synthetic Double Helix Using Helicene‐Grafted Silica Nanoparticles
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Masamichi Miyagawa Dr. Wataru Ichinose Prof. Dr. Masahiko Yamaguchi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1272-1278
Chiral silica nanoparticles (70 nm) grafted with (P)‐helicene recognized the molecular shape of double helix and random coil (P)‐ethynylhelicene oligomers in solution. A mixture of the (P)‐nanoparticles and double helix precipitated much faster than a mixture of the (P)‐nanoparticles and random coil, and the precipitate contained only the double helix. The mixture of the (P)‐nanoparticles and (P)‐ethynylhelicene pentamer reversibly dispersed in trifluoromethylbenzene upon heating at 70 °C and precipitated upon cooling at 25 °C. When a 10:90 equilibrium mixture of the double helix and random coil in solution was treated with the (P)‐nanoparticles, the double helix was precipitated in 53 % yield and was accompanied by equilibrium shift. 相似文献
434.
2‐(1‐Aryl‐2‐methoxyethenyl)benzaldehydes 2 , obtained by successive treatment of 1‐(1‐aryl‐2‐methoxyethenyl)‐2‐bromobenzenes 1 with BuLi and 1‐formylpiperidine, were transformed to the corresponding phenylhydrazones 3 on treatment with PhNHNH2. When these hydrazones were allowed to react with conc. HBr, cyclization, followed by dehydrogenation with air occurred, furnished 3‐aryl‐2‐methoxyinden‐1‐one (Z)‐phenylhydrazones 4 . 相似文献
435.
Yosuke Demizu Kaichi Sano Naoki Terayama Wataru Hakamata Yukiko Sato Hideshi Inoue 《合成通讯》2013,43(12):1724-1730
This study demonstrates solid-phase nucleophilic fluorination. Polymer-bound 1-phenoxy-2-sulfonyloxyethane, as a model compound, is converted to a fluorinated compound in a short time. Furthermore, this method is applied to synthesize a precursor of 2-deoxy-2-fluoro-D-glucose by solid-phase synthesis using a microwave oven. 相似文献
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439.
Wataru Ueda 《Catalysis Surveys from Asia》2009,13(2):143-146
Materialization of sustainable society that balances the economy and the natural environment has been high priority. For this
issue, catalysis has been regarded as a key technology and there is no doubt that catalysis researches have to be greatly
promoted everywhere in the world in order to sustain and to secure the nature, the life, and the society. Recent activities
of Catalysis Research Center in Hokkaido University for contributing to the above issues are introduced. 相似文献
440.
Wataru Shibayama Asako Narita Noriyoshi Matsumi Hiroyuki Ohno 《Journal of organometallic chemistry》2009,694(11):1642-1870
A series of triple ionic compounds consisting of double armed anions and one cation were prepared as lithium cation conductive matrices. As anions, lithium borates derived from lithium-9-borabicyclo[3,3,1]nonane hydride were introduced. The sterically hindered borate anion structures prevented the crystallization of triple ionic compounds. Introduction of ethylene oxide chains attached to the borate anions led to lower glass transition temperature, and also improved ionic conductivity. A lithium transference number of 0.73 was observed in spite of the presence of ethylene oxide chains. 相似文献