TANSO
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
Volume 2013, Issue 257
Displaying 1-9 of 9 articles from this issue
Research Papers
  • Rie Tao, Osamu Fukunaga
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 95-102
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    High-quality boron-doped diamonds were synthesized from four boron-doped carbon sources with different boron concentration using a static high-pressure process with metal solvent. Three diamond pellets obtained from the carbon sources with boron concentrations less than the solubility limit showed a homogeneous appearance and obvious X-ray diffraction patterns characteristic of diamond. The electrically-conducting diamond with 0.2 mass% of boron showed the boron-bound exciton peak characteristic of boron doping in the cathode luminescence spectra, indicating its ability as a semiconductor.
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  • Masaru Iwanaga, Yoshimasa Amano, Masami Aikawa, Motoi Machida
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 103-109
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    Dechlorination by oxidative coupling during the adsorption of mono-chlorophenols (mono-CPs) onto activated carbon (AC) was investigated, and the effects of various parameters such as amount of dissolved oxygen, surface structure and temperature of solution on dechlorination amount were examined. Under anoxic conditions, the amounts of adsorption and dechlorination for mono-CPs decreased compared to conditions where oxygen is present. This result indicated that the oxidative coupling would depend on dissolved oxygen. It is known that dissolved oxygen was transformed into reactive oxygen species on the AC surface. Therefore, we propose that reactive oxygen species originating from dissolved oxygen react with chlorophenol, causing dechlorination and the oxidative coupling by radical reaction. The introduction of pyrrole- and/or pyridine-like structures in the carbon by NH3 gas treatment at temperatures above 700 °C promoted the reduction of dissolved oxygen, which caused the increase in the amount of dechlorination. On the other hand, HNO3 oxidation of AC noticeably decreased the amount of dechlorination, indicating that the acidic functional groups possessing an electron-withdrawing ability inhibited the reduction of dissolved oxygen on the AC surface. It was also found that the amount of dechlorination and its rate were influenced by the temperature of the solution.
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  • Yutaka Kaburagi, Yasuhiro Kaitou, Emi Shindo, Akira Yoshida, Norio Iwa ...
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 110-115
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    Commercially available phenol-based carbon nanofibers (CNFs) and activated carbon nanofibers (ACNFs) about 200-500 nm in diameter were heated to 900 °C and then heat-treated further at temperatures of 3000-3200 °C. The texture and structure of the both heat-treated samples were investigated by SEM and TEM observations and measurements of XRD and Raman spectra. A large number of fine graphite particles 300-1000 nm in diameter were observed for ACNF much more than for CNF after heat treatment at high temperatures. The result supports the mechanism of generation of the particles by evaporation of carbon species at high temperatures from the nanofibers followed by the deposition, because ACNF has much larger external surface area than CNF. A large volume of graphitic regions and rather small volume of turbostratic regions were observed in the nanofibers of all heat-treated CNFs and ACNFs. The graphitic region was believed to be formed due to surface graphitization as reported for carbon sheets derived from bacteria cellulose nanofibers heat-treated at high temperatures.
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  • Hiroaki Yoshida, Yoshimasa Amano, Tom Bizley, Babak Fotoohi, Louis Mer ...
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 116-123
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    The effect of acidic functional groups on an activated carbon surface on the adsorption of benzene, phenol and nitrobenzene was examined. Adsorption experiments for these aromatics in aqueous solution were conducted using two types of activated carbon with large and small amounts of surface functional groups, DAOx and DAOxOG, respectively, to obtain the adsorption isotherms. Adsorption kinetics of nitrobenzene and phenol were also examined. The results showed that the adsorption amounts of these adsorbates were higher for DAOxOG than those for DAOx. However, the adsorbed amount of nitrobenzene on DAOx gradually increased as concentration increased, and the maximum adsorption capacity was close to that of DAOxOG. The different adsorption rates on DAOx were also observed between nitrobenzene and phenol. Two types of silica, MSU-2 and HMS, were also prepared to investigate the adsorption affinity of nitrobenzene and phenol for a hydrophilic surface. The amount of nitrobenzene adsorbed on each silica was higher than that of phenol. This indicated that nitrobenzene adsorbed more favourably on a hydrophilic surface than phenol. These results suggested that the difference in adsorptive behaviour of adsorbates on the adsorbents was due to the different adsorption mechanism of adsorbates, caused by the different polar characteristics of each substituent group.
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  • Takayuki Watanabe, Yoshimasa Amano, Motoi Machida
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 124-134
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    The adsorption capacity of 2-methylisoborneol (2-MIB) on activated carbon (AC) does not correlate with that of natural organic matter (NOM) because the adsorption property of each organic compound depends on the surface condition of AC such as pore size distribution, oxygen content and the type and number of surface functional groups. Here it was shown that the adsorption capacity of 2-MIB on AC did not correlate with that of NOM as measured by surrogate parameter of ultraviolet absorbance at 260 nm (UVA 260) in environmental water, and therefore, the adsorption mechanism was examined. Additionally, the adsorption mechanism of 2-MIB on AC was studied in distilled water, prepared according to the Japanese Standard Method. The 2-MIB adsorption mechanism was estimated from three types of adsorption isotherms (Freundlich, Langmuir and Temkin) based on the concordance between the adsorption isotherms and experimental adsorption data. Furthermore, adsorption isotherm confidence regions were estimated from the three adsorption isotherms based on statistical analysis and used for the rapid screening of AC for 2-MIB adsorption.
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  • Takahiro Kitano, Akira Iwata, Fujio Okino
    Article type: Research Paper
    2013 Volume 2013 Issue 257 Pages 135-140
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    The electrochemical performance of a novel mesophase pitch-based carbon-fiber web as an anode material in lithium-ion batteries was investigated. The web has been prepared using an aqueous solution of polyvinyl alcohol without organic solvents. The dispersion of mesophase pitch in a PVA water solution was electrospun to form a web of nanofibers. The web was heat-treated at 2800 °C in argon. Electrically conductive web-based electrodes were fabricated without a copper current collector and binder, which will lead to more compact and economical LIBs. The reversible capacity for a graphite powder used for comparison was larger than that for the web at lower rates (50-100 mA/g), but the capacity for the web was lager than that for the graphite powder at higher rates (100-3000 mA/g). The results are partially attributable to the difference in their specific surface areas. The capacity and the rate performance of the mesophase pitch-based carbon-fiber web at higher rates improved when the web was pulverized due to an increase of the specific surface area.
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Short Paper
  • Kazune Maruyama, Anna Shiono, Koji Tamada, Noboru Akuzawa, Tsutomu Tak ...
    Article type: Short Paper
    2013 Volume 2013 Issue 257 Pages 141-144
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    Carbon films were prepared from polyimide films (Kapton and Upilex-s with thickness of 50 µm) by heat treatment at 750 °C under Ar atmosphere. The electrical resistance of the carbon films was remarkably increased with the adsorption of acetone and decreased with its desorption. The magnitude of the resistance change increased with increasing vapor pressure of acetone and with decreasing temperature. The weight and resistance changes during the adsorption of acetone were simultaneously determined. A linear relationship was confirmed between them. It was also found that similar resistance changes were observed for adsorption of aqueous ammonia and nitric acid.
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Review Paper
  • Kap Seung Yang
    Article type: Review Paper
    2013 Volume 2013 Issue 257 Pages 145-148
    Published: April 01, 2013
    Released on J-STAGE: May 01, 2013
    JOURNAL FREE ACCESS
    The history of carbon science in Korea is summarized in this review. There is a record of charcoal being used to maintain collections of woodblock prints at a stable relative humidity such as the Tripitaka Koreana that were engraved from 1237 to 1248 and are designated a World Heritage Site by UNESCO. Carbon research in Korea has been led by researchers educated in foreign countries such as Germany, Japan, US, and England since the 1970s. These research activities resulted in the foundation of the Korean Carbon Society (KCS) in 1999 and its status was enhanced by hosting Carbon 2005 in Gyeongju. Nano-carbon research has further increased in universities following the award of the Nobel Prizes for research on fullerene and graphene. The regional governments of Jeonju City and Jeonbuk Province have supported the “Carbon Valley” project by establishing the Jeonju Institute of Machinery and Carbon Composites (JMC) in 2003 and inviting a Korea Institute of Science & Technology (KIST) branch, named the Institute of Advanced Composite Materials to focus on research on carbon composites in 2008. In 2011, JMC organized the 1st Carbon Industry Forum with strong support from carbon industries. In 2012, the Korean government supported the research of the Institute of Basic Science (IBS) to promote basic science in Korea and two carbon-related centers were selected.
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