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Volume 1996 (1996)
- Issue 175 Pages 243-
- Issue 174 Pages 195-
- Issue 173 Pages 137-
- Issue 172 Pages 71-
- Issue 171 Pages 2-
Volume 1996, Issue 175
Displaying 1-10 of 10 articles from this issue
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Hisashi Tamai, Sigeyuki Kojima, Makiko Ikeuchi, Juji Mondori, Takayosh ...1996 Volume 1996 Issue 175 Pages 243-248
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSActivated carbon fibers from pitch/organometallics, viz Y (acac) 3, TiO (acac) 2, Al (acac) 3, composites by steam invigoration were prepared. The pitch /organometallics homogeneous composites as starting materials were prepared using an organic solvent such as quinoline. Highly mesoporous activated carbon fibers with high specific surface area (1200-1400m2/g, mesopore ratio>70%) were obtained from pitch/Y (acac) 3 composites. On the other hand, TiO (acac) 2 and Al (acac) 3 exhibited no ability for the formation of mesoporous carbons. The adsorption of vitamin, humic acid, and cyclodextrin on the activated carbon fibers was investigated. Mesoporous activated carbon fibers from pitch/Y (acac) 3 composites showed excellent adsorption characteristics for these large molecular substances KEYWORDS: Activated carbon fiber, Mesopore, Organometallics, Rare earth metal complexView full abstractDownload PDF (2350K) -
Keiko Matsubara, Toru Katsuramaki, Kiyoshi Kawamura, Takahiko Ema1996 Volume 1996 Issue 175 Pages 249-256
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSElectron Spin Resonance of natural graphite powder, which is used as a negative electrode material of lithium ion secondary batteries, was measured between 4.2 and 300K. Observed signals were found to vary with particle size and grinding method.
Broadening of the linewidth due to conduction electron spins took place for specimens except that ground by a ball-mill down to 1μm diameter (BALL1). With lowering temperature, a narrow signal associated with localized spins was superimposed on the broad line. Temperature dependence of the g-factor and the half-value width indicates a maximum around 50K. The contribution of localized spins produced in the mechanical grinding process becomes predominant over that of conduction electron spins in the range of T<50K. On the other hand, the absorption intensity of BALL1 satisfies the Curie Law.
Samples ground by a jet-mill (JET) have large g-values as compared with those prepared by using ball and colloidal (COLL) mills. In the magnetic field, rotation of particles due to anisotropy of the diamagnetic susceptibitily was observed for the JET100 with the largest diameter 100μm. KEYWORDS: ESR, Natural graphite, Conduction electron spin, Grinding methodView full abstractDownload PDF (1105K) -
Hideaki Sano, Eiji Hayakawa, Junji Eshima, Yasuo Uchiyama, Kazuo Kobay ...1996 Volume 1996 Issue 175 Pages 257-265
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSSurface morphology and in-situ observation on the oxidation behavior of same carbon materials were investigated by laser microscope. From the observation of surface morphology of carbon fiber, glass-like carbon, C/C composite, natural graphite and heat-treated polyimide films, samples with relatively flat surface and with homogeneous reflectivity, such as glass-like carbon, natural graphite and heat-treated polyimide films, were found to be observed clearly and accurately with the limit of detectable scale of 0.1μm. From in-situ observation on oxidation behavior in air, oxidation of glass-like carbon was observed to start from surface flaw streaks, from boundary region of filler in matrix and from small pits in the matrix. And oxidation proceeded almost same speed along three dimensional all directions in the sample. On the other hand, oxidation of natural graphite and heat-treated polyimide film started from edge of graphite layer and proceeded two dimensionally along graphite layer plane. Particularly it was found that structure and texture of heat-treated polyimide films affected it's oxidation behavior. It was suggested that structure and texture of carbon materials could be clarified from in-situ observation of oxidation behavior by laser microscope.View full abstractDownload PDF (14515K) -
Yumi Osa, Takeshi Abe, Yasuo Mizutani, Mitsuru Asano1996 Volume 1996 Issue 175 Pages 266-271
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA mass spectrometric Knudsen effusion method has been used for the determination of thermodynamic properties of stage 1 FeCl3-graphite intercalation compound (GIC). Enthalpies of the transformation of stage 1 to stage 2 FeCl3-GIC by the vaporization of FeCl3 (g) and Fe2Cl6 (g), and enthalpy of the reduction of FeCl3 to FeCl2 in the stage 1 FeCl3-GIC have been determined to be 170.5±5.4, 188.2±5.4 and 144.5±4.9 kJ mol-1, respectively, from the equilibrium partial pressures over the GIC. Activities of FeCl3 and FeCl2 components in. the stage 1 FeCl3-GIC together with the activity coefficient of FeCl3 have been also evaluated. The activity coefficient of FeCl3 in the stage 1 FeCl3-GIC is found to be larger than that in the stage 2 FeCl3-GIC, indicating that the stage 1 FeCl3-GIC is thermodynamically less stable than the stage 2 FeCl3-GIC.View full abstractDownload PDF (775K) -
Kazuhiro Fujita, Hiroyuki Sakai, Norio Iwashita, Yoshihiro Sawada, Yas ...1996 Volume 1996 Issue 175 Pages 272-278
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1108K) -
Tetsuya Isshiki, Fujio Okino, Yoshiyuki Hattori, Shinji Kawasaki, Hide ...1996 Volume 1996 Issue 175 Pages 279-285
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSStructures of graphite intercalation compounds of fluorine CxF have been investigated using transmission electron microscope (TEM) in combination with XPS and X-ray diffraction (XRD) measurements. TEM lattice fringe images of CxF indicate that the sandwich thickness of semi-ionic C3.2F is smaller than that of ionic C7.3F by ca. 0.05nm in accordance with XRD results. This also supports the semi-covalent character in C-F bonds in the latter observed by XPS which allows closer contact between carbon and fluorine atoms. Although the lattice fringes of CxF are wavy compared with that of pristine graphite, they are much less wavy compared with that of covalent graphite fluoride (C2F) n indicating that the planarity of carbon layers in CxF is preserved. The waviness increases from ionic to semi-ionic CxF as the fluorine content increases. A nanobeam electron diffraction of semi-ionic C3.2F is also shown.View full abstractDownload PDF (1292K) -
Toshihiro Ando, Takashi Aizawa, Motohiko Ishi1996 Volume 1996 Issue 175 Pages 286-303
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSHydrogen, oxygen, and halogen chemisorption states on a diamond surface are investigated by three different vibrational spectroscopies; (i) Fourier-transform Infrared (FTIR), (ii) High-resolution Electron Energy Loss Spectroscopy (HREELS), and (iii) Sum-frequency Generation Spectroscopy (SFG). Diffuse reflectance FTIR and Photoacoustic FTIR are effective for use with the powder diamond samples with large surface areas. Diffuse reflectance and photoacoustic FTIR have clarified a lot of the chemisorption structures of hydrogen, oxygen and fluorine chemisorption on powdered polycrystalline diamond surfaces. HREELS is a powerful technique to observe species on single crystal diamond surfaces with small surface areas. HREE-LS has revealed a characteristic feature of hydrogen chemisorption on (100) and (111) diamond surfaces. SFG is a quite new spectroscopic technique using both a frequency fixed visible laser and a frequency tunable infrared laser to study single crystal diamond surfaces, even in a reactive gas environment. In this review, we introduce these three different vibrational spectroscopies as techniques to study diamond surface chemisorption.View full abstractDownload PDF (2753K) -
Gen Katagiri1996 Volume 1996 Issue 175 Pages 304-313
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRecent study of the Raman spectroscopy for graphite and carbon materials were reviewed, including the explanation for the structural-sensitive spectrum, the results of the measurements with very high signal-to-noise ratio, the excitation wavelength dependence, the method for the characterization of texture and microstructure and the Raman microprobe application. Some issues were also pointed out to utilize the structural-sensitive Raman spectroscopy to characterization of a variety of carbon materials.View full abstractDownload PDF (1439K) -
[in Japanese]1996 Volume 1996 Issue 175 Pages 314
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1812K) -
[in Japanese]1996 Volume 1996 Issue 175 Pages 317
Published: December 20, 1996
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (176K)
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