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961.
Dr. Ryoichi Kanega Erika Ishida Dr. Takaaki Sakai Dr. Naoya Onishi Dr. Akira Yamamoto Hiroki Yasumura Prof. Dr. Hisao Yoshida Hajime Kawanami Dr. Yuichiro Himeda Dr. Yukari Sato Dr. Akihiro Ohira 《Angewandte Chemie (International ed. in English)》2023,62(47):e202310976
For the application of CO2 as an energy storage material, a H2 storage system has been proposed based on the interconversion of CO2 and formic acid (or formate). However, energy losses are inevitable in the conversion of electrical energy to H2 as chemical energy (≈70 % electrical efficiency) and H2 to electrical energy (≈40 % electrical efficiency). To overcome these significant energy losses, we developed a system based on the interconversion of CO2 and formate for the direct storage and generation of electricity. In this paper, we report an aqueous redox flow battery system using homogeneous Ir catalysts with CO2-formate redox pair. The system exhibited a maximum discharge capacity of 10.5 mAh (1.5 Ah L−1), capacity decay of 0.2 % per cycle, and total turnover number of 2550 after 50 cycles. During charging-discharging, in situ fluorescence X-ray absorption fine structure spectroscopy based on an online setup indicated that the active species was in a high valence state of IrIV. 相似文献
962.
Naoto Ogiwara Takenobu Nakano Tsukuru Masuda Keiichiro Kushiro Madoka Takai 《Macromolecular bioscience》2023,23(5):2200486
3D structured cells have great drug screening potential because they mimic in vivo tissues better than 2D cultured cells. In this study, multi-block copolymers composed of poly(2-methoxyethyl acrylate) (PMEA) and polyethylene glycol (PEG) are developed as a new kind of biocompatible polymers. PEG imparts non-cell adhesion while PMEA acts as an anchoring segment to prepare the polymer coating surface. The multi-block copolymers show higher stability in water than PMEA. A specific micro-sized swelling structure composed of a PEG chain is observed in the multi-block copolymer film in water. A single NIH3T3-3-4 spheroid is formed in 3 h on the surface of the multi-block copolymers with 8.4 wt% PEG. However, at a PEG content of 0.7 wt%, spheroid formed after 4 days. The adenosine triphosphate (ATP) activity of cells and the internal necrotic state of the spheroid change depending on PEG loading in the multi-block copolymers. As the formation rate of cell spheroid on low-PEG-ratio multi-block copolymers is slow, internal necrosis of cell spheroid is less likely to occur. Consequently, the cell spheroid formation rate by changing the PEG chain content in multi-block copolymers is successfully controlled. These unique surfaces are suggested to be useful for 3D cell culture. 相似文献
963.
Polymerization of p‐(dimethylsilyl)phenylacetylene in toluene at 25 and 80°C using RhI(PPh3)3 as the catalyst afforded highly regio‐ and stereoregular poly(dimethylsilylene‐1,4‐phenylenevinylene)s (cis‐ 3 a and trans‐ 3 a ) containing 98% cis‐ and 99% trans‐vinylene moieties, respectively. Similarly, poly(butylmethylsilylene‐1,4‐phenylenevinylene)s ( 3 b with 91% cis‐ and 95% trans‐structures) and poly(diisopropylsilylene‐1,4‐phenylenevinylene) with 95% trans‐structure were synthesized. All polymers were soluble in common organic solvents. The trans‐type polymers showed red shifts and hyperchromic effects in the UV‐visible spectrum. The onset temperature of weight loss (T0) of cis‐ 3 a was much higher than that of trans‐ 3 a . 相似文献
964.
Makiko Seno Toshiya Ikezumi Takafumi Sumie Yasuhito Masuda Tsuneyuki Sato 《Journal of polymer science. Part A, Polymer chemistry》2000,38(11):2098-2105
The radical polymerization of N‐tert‐butyl‐N‐allylacrylamide (t‐BAA) was carried out in a dimethyl sulfoxide/H2O mixture in the presence of β‐cyclodextrin (β‐CD). The polymerization proceeded with the complete cyclization of the t‐BAA unit and yielded optically active poly(t‐BAA). The IR spectrum of the obtained polymer showed that the cyclic structure in the polymer was a five‐membered ring. The optical activity of poly(t‐BAA) increased with an increasing molar ratio of β‐CD to the t‐BAA monomer. The interaction of β‐CD with t‐BAA was confirmed by 1H NMR and 13C NMR analyses of the polymerization system. It is suggested that interaction of the t‐BAA monomer with the hydrophobic cavity of β‐CD plays an important role in the asymmetric cyclopolymerization of t‐BAA. The radical copolymerization of t‐BAA with styrene (St), methyl methacrylate, ethyl methacrylate, or benzyl methacrylate (BMA) also produced optically active copolymers with a cyclic structure from the t‐BAA unit. St and BMA carrying a phenyl group were predicted to compete with t‐BAA for interaction with β‐CD in the copolymerization system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2098–2105, 2000 相似文献
965.
The polymerization of bis(4‐ethynylphenyl)methylsilane catalyzed by RhI(PPh3)3 afforded a regio‐ and stereoregular hyperbranched polymer, hb‐poly[(methylsilylene)bis(1,4‐phenylene‐trans‐vinylene)] (poly( 1 )), containing 95% trans‐vinylene moieties. The weight loss of this polymer at 900°C in N2 was 9%. Poly( 1 ) displayed an absorption due to π‐π* transition around 275 nm as a shoulder and a weak absorption around 330 nm due to π‐to‐σ charge transfer, which was hardly seen in the corresponding linear polymer. 相似文献
966.
Seizo Masuda Tomiharu Miyahara Keiji Minagawa Masami Tanaka 《Journal of polymer science. Part A, Polymer chemistry》1999,37(9):1303-1309
Radical polymerization of methacryloylglycine (MGly) was kinetically investigated in distilled water and dimethyl sulfoxide. In both solvents, the polymerization obeys a conventional radical equation (rule of square root). Monomer reactivity ratios rMGly = 0.64 and rSt = 1.21 were obtained in the copolymerization of MGly and styrene (St) in DMSO. On the basis of the monomer reactivity ratios obtained, copolymerization parameters QMGly and eMGly were calculated to be 0.55 and −0.29, respectively. Complexation constants of divalent metal ions with MGly and its polymer (PMGly) were determined by the modified Bjerrum method. The complexation constants of PMGly were larger than those of MGly. However, there is no difference between complexing abilities of PMGly and polyacrylic acid, although the additive effect of amide and carboxyl groups was expected on the complexation. The interactions of MGly and PMGly with Cu(II) and Mn(II) ions were studied using 13C‐NMR. The addition of copper(II) nitrate solution to MGly and PMGly solutions selectively broadens the methylene carbon and carboxyl carbon signals, and the addition of manganese(II) nitrate solution broadens the amide carbon and carboxyl carbon signals. These findings suggest that Cu(II) and Mn(II) ions form five‐ and seven‐membered chelate rings, respectively. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1303–1309, 1999 相似文献
967.
968.
969.
Masahiro Teraguchi Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》1998,36(15):2721-2725
Polymerization and polymer properties of 1-phenyl-2-[4-(triphenylsilyl)phenyl]acetylene (pPh3SiDPA) and 1-phenyl-2-[4-(triisopropylsilyl)phenyl]acetylene (piPr3SiDPA), which have very bulky silyl groups, were examined. These monomers polymerized in good yields in the presence of TaCl5-based catalysts. The highest weight-average molecular weights of poly(pPh3SiDPA) and poly(piPr3SiDPA) reached about 1 × 106 and 4.8 × 106, respectively. The polymers were yellow to orange-colored solids which were soluble in toluene, chloroform, etc., and provided free-standing films by solution casting. The onset temperatures of weight loss of poly(pPh3SiDPA) and poly(piPr3SiDPA) in TGA in air were 430 and 270°C, respectively. The oxygen permeability coefficients of poly(pPh3SiDPA) and poly(piPr3SiDPA) at 25°C were 3.8 and 20 barrers, respectively, and relatively small. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2721–2725, 1998 相似文献
970.
Hidehiro Ito Toshio Masuda Toshinobu Higashimura 《Journal of polymer science. Part A, Polymer chemistry》1996,34(14):2925-2929
1-Phenyl-2-[m-(trimethylgermyl)phenyl]acetylene (m-Me3GeDPA) and 1-phenyl-2-[p-(trimethylgermyl)phenyl]acetylene (p-Me3GeDPA) polymerized with TaCl5–cocatalyst systems to provide in high yields new polymers having weight-average molecular weights over 1 × 106. Poly(m-Me3GeDPA) was a yellow solid, which completely dissolved in toluene, chloroform, etc., to form a tough film by solution casting. Poly(p-Me3GeDPA) was also a yellow solid and partly insoluble in any solvents. The onset temperatures of weight loss for these polymers in the thermogravimetric analysis in air were as high as ca. 400°C. The oxygen permeability coefficient of poly(m-Me3GeDPA) was 1100 barrers (25°C), which is about twice that of poly(dimethylsiloxane). © 1996 John Wiley & Sons, Inc. 相似文献