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Volume 2008 (2008)
- Issue 235 Pages 263-
- Issue 234 Pages 215-
- Issue 233 Pages 115-
- Issue 232 Pages 61-
- Issue 231 Pages 2-
Volume 2008, Issue 235
Displaying 1-9 of 9 articles from this issue
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Yusuke Kuwabara, Hironori Yano, Yoshiaki Kanematsu, Hirokazu Oda2008 Volume 2008 Issue 235 Pages 263-267
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe porous structures of the mesoporous carbon materials, which are known to be effective energy storing systems, were manipulated and their behaviors as electric double-layer capacitor electrodes were evaluated. Resorcinol (R) as the raw material and acetaldehyde (A) as the cross-linking agent were used to synthesize the RA hydrogels via sol-gel polycondensation in a slightly basic aqueous solution. The RA hydrogels were freeze-dried and subsequently pyrolyzed at 1073 K for 30 min (heating rate, 10 K/min) to obtain the RA carbon cryogels. The obtained samples were confirmed to have a high mesoporous carbon content, with the primary pore size diameter distribution of 20 to 40 nm. Due to a high ratio of ion adsorption and desorption capacitances, the samples were effective electrode materials capable of high-speed electrical charge and discharge for use as electrode materials of electric double layer capacitors.View full abstractDownload PDF (3066K) -
Manabu Okuyama, Akira Teramoto, Masaru Watanabe, Hiroshi Inomata2008 Volume 2008 Issue 235 Pages 268-274
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe solvent-free chemical modification (SFM) of fullerene (C60) by polyethylene glycol with amino terminal (amino-PEG) was studied in order to improve the fullerene dispersability. The effect of the stirring rate and the C60 particle size on the modification yield was investigated in the temperature range 60-120°C for 3-24 h. As a result, 65 % of C60 was modified at 60°C for 24 hr to disperse in ethanol. The effect of C60 particle size on the yield was found to be more significant than that of the stirring rate. Therefore, the SFM is more sensitive to the collision frequency between C60 and amino-PEG compared to the diffusion of C60 in amino-PEG.
In order to understand the chemical modification mechanism, simulation was performed based on a shrinking-core model assuming a chemical reaction as a rate limiting step.Using this model it was possible to estimate the number of amino-PEG molecules attached to C60. The results of simulation fit well the gel permeation chromatography (GPC) data collected in the early period of reaction considering that one amino-PEG attached to C60. As for the final period of reaction, the number of attached amino-PEG molecules increases according to the GPC data but the simulation shows opposite tendency.This tendency was explained by decrease in C60 surface activity and by the additional reaction between products in the fluid phase.View full abstractDownload PDF (1740K) -
Taku Iiyama, Sumio Ozeki2008 Volume 2008 Issue 235 Pages 275-279
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe in situ small-angle X-ray scattering (SAXS) of water and CCl4 adsorbed on pitch-based activated carbon fibers (ACF) were measured at 303 K. We extended the Debye-Bueche theory to the 3-phase mixed system (solid phase: carbon, adsorbed phase, and vacant space) to obtain the average dimension of each phase (ls, la, and lv). The la of water in wider pore system (pore width: ω=1.13nm) increases with the fractional filling φ. On the other hand, la in smaller pore system (ω=0.75nm) does not change with φ. These results show the difference in the cluster growing process with the pore width. It seems that the difference in the size and shape of water clusters in the adsorption and desorption processes should lead to the adsorption hysteresis. The developed analysis method may give the direct information on molecular assemblies in micropores.View full abstractDownload PDF (1031K) -
Susumu Takabayashi, Keishi Okamoto, Tatsuyuki Nakatani, Hiroyuki Sakau ...2008 Volume 2008 Issue 235 Pages 280-289
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDiamondlike carbon (DLC) is an amorphous carbonaceous material composed of sp2 carbon, sp3 carbon, and hydrogen.We have analyzed the chemical structure of DLC by using X-ray photoelectron spectroscopy (XPS). In this paper, we reviewed our DLC analysis. The C ls spectra of the DLC films were analyzed using the Doniach-Šunjic function convoluted with a Gaussian function. The spectra were decomposed into four components as follows: sp3 carbon with carbon-carbon bonds (C-C sp3 carbon, 283.8 eV), sp2 carbon with carbon-carbon bonds (C-C sp2 carbon, 284.3 eV), sp2 carbon with hydrogen-carbon bonds (H-C sp2 carbon, 284.8 eV), and sp3 carbon with hydrogen-carbon bonds (H-C sp3 carbon, 285.3 eV).View full abstractDownload PDF (2137K) -
Hirofumi Kanoh2008 Volume 2008 Issue 235 Pages 290-295
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSNanoporous metals and nanometals need stabilizers which prevent them from sintering or oxidizing. Nanoporous Pt, Ni, or Pd, which were prepared by using silica nanoparticles or PVA films as templates, can be stabilized by a trace or small amount of carbons, which coat surfaces of the metals. Also, single wall carbon nanohorn can be a good stabilizer and catalyst support. The properties of such nanocarbons are reviewed for stabilization of nanometals.View full abstractDownload PDF (2414K) -
Hirokazu Oda2008 Volume 2008 Issue 235 Pages 296-306
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSIt is considered that the total performances of porous carbon materials have been appraised almost entirely by the factors of specific surface area and pore-size and its distribution, while little attention has been paid on the problems focused among the interface chemistry and physico-chemical nature of the surface of carbon materials. The procedures for the modification of the various kind of carbons were described and it was shown that the standardization of the formed functional groups and pore structure of carbons. In this paper, quantitatively the effect of functional groups of activated carbon electrodes on electric double layer and removal of various electrolytes from aqueous solution and/or recycling operation characteristics were reported as its application.View full abstractDownload PDF (3972K) -
Takashi Kyotani, Hironori Orikasa, Hirotomo Nishihara2008 Volume 2008 Issue 235 Pages 307-315
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (4604K) -
Izumi Shimoyama, Kiyoshi Fukada2008 Volume 2008 Issue 235 Pages 316-324
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (2492K) -
[in Japanese]2008 Volume 2008 Issue 235 Pages 332-334
Published: November 17, 2008
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1919K)
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