All issues
Volume 2012 (2012)
- Issue 255 Pages 225-
- Issue 254 Pages 153-
- Issue 253 Pages 95-
- Issue 252 Pages 47-
- Issue 251 Pages 2-
Volume 2012, Issue 252
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
Research Papers
-
Miki Sakuma, Yoshimasa Amano, Motoi MachidaArticle type: Research Papers
2012 Volume 2012 Issue 252 Pages 47-53
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL FREE ACCESSBamboo charcoals were prepared by low temperature carbonization at 500 °C, and subsequent treatments such as air oxidation at 180-380 °C for the introduction of functional groups on the surface, and outgassing at 1000 °C for their removal were conducted to examine the relationship between the amount of water vapor adsorption and the surface properties of the prepared charcoals. The air oxidation treatment was effective in developing surface area and pore volume as well as surface functional groups, and the developments were in proportion to the treatment temperature. Air oxidation of the prepared charcoal at 380 °C increased surface area from 250 m2/g to 590 m2/g and pore volume from 0.16 mL/g to 0.31 mL/g. At a relative humidity below 50%, the charcoals oxidized at 380 °C were able to adsorb approximately twice the amount of water vapor compared to those oxidized at 180°C and 280 °C, indicating that the water vapor adsorption depends on the surface functional groups. In a relative humidity above 50%, the outgassed bamboo charcoals adsorbed a large amount of water vapor, indicating that mesopores and macropores, rather than surface functional groups, contributed to water vapor adsorption.View full abstractDownload PDF (1050K) -
Masaki Okada, Makoto Tatsumi, Naoto OhtaArticle type: Research Papers
2012 Volume 2012 Issue 252 Pages 54-62
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL FREE ACCESSThe effect of the residence time at different temperatures on the graphitization of an isotropic baked block was investigated by measuring the changes in structural and physical properties; lattice constant c0, real density, resistivity, hardness and mechanical properties. Samples were heat-treated at different temperatures ranging from 2100 to 3000 °C for residence times from 3 to 960 min. Three different calcined cokes, two derived from pitches with either mosaic or needle-like textures, and one derived from petroleum with a mosaic texture, were also heat-treated and analyzed for comparison. Master curves for properties were obtained on the baked block by a time-temperature superposition rule, and discussed by comparing with those of cokes. The same shift factors to convert between heat-treatment temperature and time could be used to obtain master curves for the structural and physical properties measured, suggesting that the graphitization of these isotropic baked block and calcined cokes proceeds by almost the same process.View full abstractDownload PDF (2080K) -
Tomoyoshi Sugiura, Toru Noguchi, Masatsugu Fujishige, Shigeki Inukai, ...Article type: Research Papers
2012 Volume 2012 Issue 252 Pages 63-67
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL FREE ACCESSThis paper reports changes in the electrical conductivity of multi-wall carbon nanotube/natural rubber (MWNT/NR) composites as a function of nanotube loading and nanotube diameter (φ). The percolation threshold of the φ13 nm MWNT/NR composite was found at a filler content of 2.9 wt%. A volume resistivity of a few 10−2 Ωm was obtained at 16.7 wt% of φ13 nm MWNTs, which is almost half the 37.5 wt% needed for φ67 nm MWNTs. It has been found that the electrical resistivity depends little on the shape of the MWNTs based on the two-dimensional models of electrical path for the straight and round MWNTs. Since the good mechanical properties of thin MWNT/NR composites at 120 °C have already been reported, it would be expected that the application of these composites might be broaden.View full abstractDownload PDF (3165K)
Review Papers
-
Michio InagakiArticle type: Review Papers
2012 Volume 2012 Issue 252 Pages 68-77
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL RESTRICTED ACCESSThe formation of carbon nanotubes into forests, yarns and films is reviewed. In forests formed on a substrate with a catalyst metal layer, carbon nanotubes are oriented with their tube axis perpendicular to the substrate. Carbon nanotube yarns are prepared either by spinning a suspension of them under different circumstances, in-situ spinning during their preparation or by direct spinning from their forest. Carbon nanotube films are prepared either by filtering their suspension, in-situ formation or direct drawing.View full abstractDownload PDF (6242K) -
Hiroshi ShioyamaArticle type: Review Papers
2012 Volume 2012 Issue 252 Pages 78-83
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL RESTRICTED ACCESSStudies on the template carbonization technique using a variety of metal-organic frameworks (MOFs) are reviewed. The carbonization of organic compounds such as furfuryl alcohol or phenolic resin introduced in the three-dimensional openings in the MOF produces materials with a high specific surface area. Nanoporous carbons thus prepared yield high electric doublelayer capacitance and high hydrogen storage capacity. The carbonization of the organic ligand, i.e. the constituent of the MOF, is also discussed. In the last part of this article, the preparation of novel composites of MOF and graphite oxide is described.View full abstractDownload PDF (3195K)
Recent Doctoral Thesis
-
Hiroyuki ItoiArticle type: Recent Doctoral Thesis
2012 Volume 2012 Issue 252 Pages 84-86
Published: January 15, 2012
Released on J-STAGE: May 18, 2012
JOURNAL RESTRICTED ACCESSZeolite-templated carbon (ZTC), prepared by using zeolite as a template, has a regularly-arrayed and mutually connected pore structure with uniform pore size (1.2 nm) because ZTC is a negative replica of template zeolite. Its framework is comprised of backybowl-like curved nanographenes linking each other and ZTC has a high surface area capable of adsorbing large amount of molecules and ions. Moreover, its three-dimensionally connected and regularly-arrayed pore structure decreases the ion diffusion resistance of molecules and ions. By taking its advantage, it is expected that ZTC can be used for high hydrogen storage materials and electrodes of electrochemical capacitors with high energy and power densities. In this study, we report high electrochemical performances of ZTC as an electrode material in both organic and aqueous electrolytes. Next, we report hydrogen storage properties of ZTC combinded with an organo-platinum complex.View full abstractDownload PDF (844K)
- |<
- <
- 1
- >
- >|