Transactions of the Materials Research Society of Japan
Online ISSN : 2188-1650
Print ISSN : 1382-3469
ISSN-L : 1382-3469
44 巻 , 1 号
選択された号の論文の9件中1~9を表示しています
Review Paper
Regular Papers
  • Koichi Niwa, Syohei Hisamatsu, Tomomi Hakuro, Ryousuke Miura, Mutsumi ...
    2019 年 44 巻 1 号 p. 7-11
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    The effect of various excess oxygen gas flows at the cathode of a direct ethanol fuel cell (DEFC) was investigated with respect to the reaction products/intermediates. The output current increased with the excess oxygen gas flow. For each oxygen flow, the acetic acid concentration at anode was 5 times higher than the acetaldehyde concentration; therefore, acetaldehyde is readily oxidized to acetic acid or acetic acid is formed directly. This suggests that the output current is mainly dependent on the amount of acetic acid produced. The maximum concentration of acetaldehyde with each output current was almost proportional to that of acetic acid for each oxygen flow condition. The effect of cerium oxide addition to the cathode as another oxygen source to enhance performance was also examined. After an excess oxygen gas flow of 0.6 L/min was stopped, the output current increased for approximately 2 minutes, after which the cerium oxide re-absorbed oxygen to attain equilibrium, which was accompanied by a decrease in the output current until it returned to the same level as that with the excess oxygen gas flow. Thus, the addition of cerium oxide to the cathode enhances oxygen supply for cathodic reactions with a corresponding increase in output current.

  • R. Sakuma, K. Sawada, K. Nakashima, T. Tsukegi, S. Osawa, O. Yoshimura
    2019 年 44 巻 1 号 p. 13-16
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    In this study, a novel antibacterial polymeric material with low environmental impact was produced by using cellulose acetate butyrate (CAB), a biodegradable plastic, and hiba oil, a natural antibacterial agent. The method of material preparation, antibacterial performance, and mechanical properties were evaluated. When the film was prepared using acetone, hiba oil did not disperse, and a white film was produced. When the film was prepared using chloroform, which is not miscible with water, hiba oil was uniformly dispersed in CAB, and a transparent film was produced. Antibacterial performance was obtained by the inclusion of hiba oil at 20 wt% of CAB. In addition, hiba oil conferred flexibility to CAB through its action as a plasticizer.

  • Sho Yamamoto, Norihisa Kawamura, Toru Nonami
    2019 年 44 巻 1 号 p. 17-23
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    Phosphorus is the main cause of eutrophication due to its excessive discharge as wastewater. Diopside adsorbs phosphorus and deposits apatite on the surface of diopside. Therefore, the amount of phosphorus adsorbed is proportional to the amount of apatite deposited. Consequently, we investigate the potential of diopside as a phosphorus adsorption material. In this study, we synthesized diopside by a sol-gel method and evaluated the amount of deposited apatite. After dissolving 0.125 mol each of Ca(NO3)2·4H2O and MgCl2·6H2O in 150 mL ethanol, 0.250 mol Si(OC2H5)4 was added and the mixture was stirred for 1 hour. It was then left undisturbed for 24 hours at 80°C to obtain a colorless, transparent gel. The gel was then sintered at 650°C–800°C. Subsequently, 1 g samples of the diopside were soaked in 1 L pseudo body solution (NaCl: 136.89 mmol, KCl: 2.68 mmol, KH2PO4: 1.47 mmol, Na2HPO4: 8.10 mmol, CaCl2∙2H2O: 0.68 mmol) for 1 hour. The state of the deposited apatite was evaluated by scanning electron microscopy and powder X-ray diffraction. The results showed that diopside sintered at 650°C–700°C exhibited at least 50% more deposited apatite than that sintered at 600°C. Therefore, diopside sintered at 650°C–700°C was applied as the phosphorus adsorption material.

  • Masao Ishinabe, Kaname Tsutsumiuchi, Kenichi Imaeda
    2019 年 44 巻 1 号 p. 25-28
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    PET films were dipped in solvents and subsequently tested for heat-resistance at low temperatures and low elongation. The results indicate that acetaldehyde can impart high heat-resistance to the film and prevent solvent leakage. The solvent was selected to investigate the strength of the negative charge of the aldehyde carbonyl group and find a solvent which would further enhance the heat-resistance of the film. Solvents with carbonyl groups containing strong negative charges were chosen while considering the dielectric constant, which, in general, strongly influences solvent crystallization. Dimethyl sulfoxide was selected as a solvent because of its extremely high dielectric constant. For comparison, ethyl acetate, which has a lower dielectric constant, was chosen as a solvent along with acetaldehyde, which has a moderate dielectric constant. The PET films were inserted in boiling water after elongation, at which ethyl acetate caused a high heat-resistance of 1471 cm-1. This result showed that a low dielectric constant is not correlated with the heat-resistance of the resulting film.

  • Masahiko Nagaki, Narishige Soma, Kouta Ono, Kanako Yamanouchi, Takakiy ...
    2019 年 44 巻 1 号 p. 29-33
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    Biotransformations of indanol, fluorenol and their analogs were performed using carrot (Daucus carota) calli as biocatalysts. Biotransformation of indanol yielded indanone at 24% on day 14, 26% on day 25, and 32% on day 41. Conversely, when indanone was used as a substrate, no reaction was observed. Biotransformation of fluorenol using D. carota produced fluorenone at 22% after 2 days. Fluorenone was obtained at 25% on day 8, 47% on day 10, 54% on day 16, and 79% on day 25. Likewise, no reaction was observed when fluorenone was used as a substrate. We conducted antimicrobial tests on these compounds using the sensitive disc method. Three reagents, indanol, indanone and fluorenol, showed very strong activity (+++) against the Gram-positive bacterium methicillin-resistant Staphylococcus aureus. All four tested reagents showed + activity against the fungus C. albicans. Indanol and indanone showed weak activity against Gram-negative bacteria Escherichia coli, enterohemorrhagic Escherichia coli and Pseudomonas aeruginosa, while fluorenol and fluorenone showed no effect against any Gram-negative bacteria tested.

  • Yasushi Umeda, Yuki Nakabayashi, Tatsuo Nagai, Katsuhiko Tashiro, Hide ...
    2019 年 44 巻 1 号 p. 35-39
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    Mixture of chromic acid and sulfuric acid has been widely applied for hydrophilization of ABS resin. However, it is difficult to make the hydrophilic surface of PP resin, because chromic acid has poor oxidizing power for PP resin. In addition, due to environmental concerns, alternative technologies that do not use hexavalent chromium are required. The authors have confirmed that PP resin and ABS resin can be hydrophilized with electrolyzed sulfuric acid solution and then be plated to obtain enough adhesion strength in practical use. In this report, focusing on its hydrophilization behavior, we investigated the reason why hydrophilization is created, and assumed that hydrophilization is due to oxygen entering between bonds of carbon and hydrogen to become hydroxyl groups.

  • Toshimasa Suzuka, Naoki Takayama, Masanori Unten, Kaoru Onda, Kazuhito ...
    2019 年 44 巻 1 号 p. 41-44
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

      A novel homogeneous transition-metal catalyst, a polymer-supported terpyridine–palladium(II) complex, was found to promote the allylic alkylation with phenylborinic acid under phosphine-free conditions in water with good yield. The catalyst was recovered and reused several times without loss of catalytic activity. To our knowledge, this is the first example of the allylic alkylation with pheylboronic acid in water using a polymer-supported terpyridine–palladium(II) complex under aerobic conditions. The stereochemistry of the allylic alkylation with phenylboronic acid was demonstrated to be not net retention.

  • Hideaki Kamiyama, Osamu Takai
    2019 年 44 巻 1 号 p. 45-50
    発行日: 2019/02/01
    公開日: 2019/02/01
    ジャーナル フリー

    The authors synthesized carbon nitride films on chromium steel substrate under various conditions by unbalanced magnetron sputtering method. As a result of changing the flow rate of N2 gas and Ar gas during deposition, it was found that the film thickness and the amount of nitrogen inside the film increased with the increase in nitrogen gas. Further, in the plasma during synthesis, an increase in CN emitting species could be also confirmed by the increase in gas flow rate. In addition, when the substrate bias voltage was -100 V or less, it was found that the film thickness decreased and the chemical bonding state changed, but the hardness of the film was constant at 10 to 15 GPa. However, when the substrate bias voltage was not applied, the film hardness was constant at 6 to 10 GPa. The nitrogen concentration in the films was 25atom% at the maximum. As a result of a friction test, the friction coefficient of a carbon nitride film was equal to or less than that of a DLC film under machine oil condition.

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