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Volume 2007 (2007)
- Issue 230 Pages 293-
- Issue 229 Pages 233-
- Issue 228 Pages 143-
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Volume 2007, Issue 228
Displaying 1-13 of 13 articles from this issue
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Akira Yoshida, Yutaka Kaburagi, Yoshihiro Hishiyama2007 Volume 2007 Issue 228 Pages 143-152
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSMesophase-pitch-based carbon fiber P 100 is known as a well-oriented carbon fiber in which the partially graphitized crystallites align along the fiber axis. The X-ray powder diffraction pattern for P 100 measured by the X-ray diffractometer reveals the 100 diffraction line as a composite peak with the 101 diffraction line. The composite peak is usually not easy to separate into the component peaks of 100 and 101 lines. In the present article, a method to measure the single 100 diffraction line with the X-ray diffractometer using fiber samples of P100 has been developed. It has been found that there exist two types of crystallites oriented to their basal planes along the fiber axis in each of the P 100 fibers; the Z-type crystallite with the zigzag boundary planes and the A-type crystallite with the armchair boundary planes, both of the boundary planes are perpendicular to the fiber axis. The average crystallite sizes along the fiber axis evaluated are 53 nm for the Z-type crystallites and 80 nm for the armchair crystallites. The average crystallite thickness for both types is about 120 nm.View full abstractDownload PDF (2398K) -
Jun-ichi Ozaki, Tomonori Anahara, Naofumi Kimura, Chiemi Ida, Asao Oya ...2007 Volume 2007 Issue 228 Pages 153-157
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSBN-doped carbon blacks were prepared by mechanochemical alloying of a carbon black and h-BN (h-BN doping ratio: 0-50 at%). The structure, the surface chemical states and the catalytic activity for an electrochemical oxygen reduction reaction of the prepared carbons were investigated. XRD and TEM studies revealed the following influences of h-BN on the structure of the carbon black; i.e. the reduction in the d002-spacing and the loss of the alignment of the graphene layer in the primary particles of the carbon black. Detailed studies were conducted for the 20 at% BN-doped carbon black, since incomplete alloying was observed obviously for the samples with higher doping levels than 33 at%. XPS studies proved the formation of B-C and N-C bonds as well as B-N-C moieties, which indicated a mechanochemical reaction between the carbon black and h-BN, took place during mechanical treatment. Hence, the mechanical treatment of carbon black and h-BN could provide BN-doped carbon blacks. Increases in the activities of carbons for the oxygen reduction reaction were observed by the mechanical treatment; i.e. only a simple treatment without h-BN could increase the activity by 17 times that of the pristine carbon black, and a further 10 fold enhancement was observed for the BN-doped carbon.View full abstractDownload PDF (1302K) -
Makoto Nakanishi, Yukiko Uchida, Tatsuo Fujii, Jun Takada, Yoshihiro K ...2007 Volume 2007 Issue 228 Pages 158-162
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSWe have prepared Carbon/Fe-Ni-Cu ternary alloy composites by polymerized complex method. A single-phase Fe-Ni-Cu alloy could be obtained in carbon matrix by controlling pH of the citrate complex solution. It was revealed that the chemical compositions of metals in composites were maintained well by adding ethylene glycol into the complex solution. Crystallinity of both carbon matrix and Fe-Ni-Cu alloy particles were enhanced with increasing the carbonized temperature. The composite carbonized at 700°C had larger saturation magnetization and smaller coercivity than that carbonized at 500°C, which correlated with metal content and crystallite size of alloy. The composite carbonized at 700°C exhibited larger permeability and permittivity than carbon/Fe-Co alloy composites at frequency of GHz range.View full abstractDownload PDF (1152K) -
Optimal amount for the best performanceMasato Kojima, Yong Jung Kim, Morinobu Endo2007 Volume 2007 Issue 228 Pages 163-165
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe feasibility of mass-produced multi-walled carbon nanotubes (MWNTs) as an additive for supercapacitor and its optimal addition amount was investigated by using of a practical measurement of supercapacitor. When considering rate capability (1-60 mA/cm2) for the addition amount of MWNTs at 10, 20 and 30 wt.%, the addition of 10 wt.% was no large deterioration capacitance as a function of the current density compared to no addition. Thus, the addition of 10 wt. % was optimal addition amount of MWNTs.View full abstractDownload PDF (809K) -
Yousuke Kobayashi, Ken-ichi Fukui, Koichi Kusakabe, Toshiaki Enoki2007 Volume 2007 Issue 228 Pages 166-173
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe presence of structure-dependent edge states of graphite has been revealed by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) observations under ultrahigh vacuum. On a hydrogen-terminated zigzag edge, at a bias voltage near the Fermi energy, bright spots are observed in STM images, demonstrating that the zigzag edge is responsible for the edge states. The edge states at the zigzag edge show different spatial distributions depending on whether the edge atoms are the α-or β-edge carbon termination and on the size of thezigzag edge. The amplitude of the edge state around the structural defects in an armchair edge often has a prominent hump spreading in a direction determined by local atomic structure of the edge. The tight binding calculation based on the atomic arrangements observed by STM well reproduces the observed spatial distribution of the local density of states.View full abstractDownload PDF (2727K) -
Recent advances and their applications to nano-carbonsMinoru Osada, Masato Kakihana2007 Volume 2007 Issue 228 Pages 174-184
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe application of Raman spectroscopy to the characterization of carbon-based materials is reviewed. Carbon can exhibit various structural arrangements in the solid state, such as the well-known graphite and diamond, as well as the hrecently discovered allotropic forms based on fullerene, nanotube and graphene.The characteristic Raman spectra are presented for these different forms of carbons. We also address recent advances in Raman spectroscopy and their applications to carbon-based materials. These include resonant Raman scattering of single wall carbon nanotube, selective characterization of sp3-bonded C atoms in diamond-like amorphous carbon, Raman imaging of diamond isynthetic diamond film and nano-Raman spectroscopy of single wall carbon nanotube.View full abstractDownload PDF (2666K) -
Hiroyuki Fujimoto2007 Volume 2007 Issue 228 Pages 185-194
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe diffraction profile of carbon materials has been quantitavely analyzed by many researchers for more than fifty years and the structural parameters such as lattice constants, crystallite sizes, graphitizability and Debye-Waller factor have been proposed together with their estimation method. In the present article, the conventional method ever proposed are reviewed and the next-generation analytical theory of carbon structure will be overviewed.View full abstractDownload PDF (2113K) -
Soshi Shiraishi2007 Volume 2007 Issue 228 Pages 195-199
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIn this review, it is explained how to characterize the activated carbon electrode for electric double layer capacitor (EDLC) and what points to pay attention to. Both of the power density and energy density of EDLC can be obtained using two-electrode type cell by constant power method or constant current method. The power density depends on the energy density. Additionally, the end of discharge voltage controls them. It is necessary to conduct the acceleration life-test at high charge-voltage and high temperature condition using two-electrode type cell for characterizing the cycle performance of EDLC. An overestimation of BET specific surface area often causes misunderstanding the correlation of the surface area and the capacitance of activated carbons. The BET specific surface area should be calculated in consideration of the analysis condition. The capacitance in ethylimidazolium-type ionic liquid cannot be measured by three-electrode cell with Li/Li+ reference electrode since lithium metal is reactive to the ionic liquid. The surface modification of lithium metal by HF can suppress the reaction to use Li/Li+ reference electrode in the ionic liquid.View full abstractDownload PDF (1247K) -
Keita Ozawa, Sung-Moo Song, Sotaro Yamauchi, Hiroki Wada, Koh-ichi Sug ...2007 Volume 2007 Issue 228 Pages 200-205
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSC/VGCF porous foams composed of aromatic resin (AR) and Vapor Grown Carbon Fiber (VGCF) were developed for pre-form of Metal/C/VGCF composite with high thermal conductivity. The foams had continuous and homogeneous open cell network by pre-heat treatment at 460°C VGCF uniformly dispersed in carbon matrix of the foams. Pore size and bulk density of the foam could be controlled by temperature and pressure on pre-heat treatment. The C/VGCF foams possessed high compressive strength when the foams were graphitized at 3000°C. In addition, the graphitized foam exhibited low thermal expansion coefficient and high degree of graphitization. Consequently, the graphitized foam was expected for an ideal pre-form for Metal/C/VGCF composites with high thermal conductivity.View full abstractDownload PDF (2103K) -
Hiroshi Shioyama2007 Volume 2007 Issue 228 Pages 206-208
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIntercalation of CuCl2 into graphite was carried out by a two-zone method. The observation of products by X-ray powder diffraction showed that the extent of CuCl2intercalation could be controlled through adjustment of the pressure of argon gas in the reaction tube. The preparation of stage 4 and 6 CuCl2-graphite intercalation compounds was successful, which could not easily obtained by the standard two-zone method without argon.View full abstractDownload PDF (481K) -
Yoshiaki Matsuo2007 Volume 2007 Issue 228 Pages 209-214
Published: June 15, 2007
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSDownload PDF (2461K) -
Hisanori Sugimoto2007 Volume 2007 Issue 228 Pages 215-219
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (2143K) -
[in Japanese]2007 Volume 2007 Issue 228 Pages 228
Published: June 15, 2007
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (155K)
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