炭素
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
2016 巻, 273 号
選択された号の論文の7件中1~7を表示しています
2014年度受賞レビュー
  • 白石 壮志
    2016 年 2016 巻 273 号 p. 75-82
    発行日: 2016/06/15
    公開日: 2016/07/15
    ジャーナル 認証あり
    In this review, the author outlines the electrochemical capacitance properties of carbon materials prepared by the defluorination of fluorocarbon materials, such as polytetrafluoroethylene (PTFE), fluorinated hetero-organics, or graphite fluoride with alkali metals or alkali cation-naphthalene anion radical complexes. The surface area and pore size distribution of the PTFE-based porous carbons prepared through the defluorination technique without any conventional activation can be controlled by optimizing the defluorination conditions. These PTFE-based nanoporous carbons show an better rate performance of the capacitance than do conventional activated carbons due to their developed mesoporous structure which suppresses the ion-sieving effect and accelerates ion adsorption/desorption in the pores even when the electrolyte ion is bulky. Fluorinated hetro-organics can be defluorinated as well as PTFE to provide nitrogen- or boron-doped nanoporous carbons. A lamellar-like carbon material with low specific surface area and a large interlayer spacing, obtained by the defluorination of graphite fluoride, shows a high capacitance that depends on polarization voltage. In conclusion, the defluorination technique produces carbon materials suitable for capacitors, leading to new type of porous carbon electrode.
2015年度受賞レビュー
  • 向井 紳
    2016 年 2016 巻 273 号 p. 83-88
    発行日: 2016/06/15
    公開日: 2016/07/15
    ジャーナル 認証あり
    The production of materials involves various mass and heat transfer processes which are usually intertwined in a complicated manner. Therefore how to harmonize such processes often becomes the key for efficient material production. Various mass and heat transfer processes must also be carefully considered in order to efficiently utilize the produced materials. However in many cases, materials are produced or used under conditions in which the mass and heat transfer processes involved are far from a harmonized state. In order to improve efficiency, precise analysis of the involved mass and heat transfer processes is required, as processes which lead to the decrease in efficiency must be clarified first. Considering the fact that chemical engineers are very proficient in such analyses, approaches based on chemical engineering are expected to be very helpful in improving the efficiency of the production and/or utilization of materials. The author has frequently used such approaches to develop or improve processes to produce various functional carbon materials. This article describes how such approaches led to the improvement of the production processes of carbon nanofibers, monolithic carbon gels with a microhoneycomb structure and graphene oxide.
  • 藤森 利彦
    2016 年 2016 巻 273 号 p. 89-95
    発行日: 2016/06/15
    公開日: 2016/07/15
    ジャーナル 認証あり
    We review our recent progress on the fabrication of artificial one-dimensional (1D) conductors using the carbon nanotube-template method. We demonstrate that carbon nanotubes (CNTs) have the ability to stabilize previously-unobserved 1D crystals of chalcogen elements inside their quasi-1D channels. Most importantly, we found by experiment and theory that 1D sulfur crystals, which consist of monatomic zigzag or linear conformations, exhibit a metallic character inside CNTs. Despite the fact that both sulfur and selenium show similar molecular structures in the bulk phase, selenium forms double-helices inside double-wall CNTs. Our theoretical calculations predict that selenium double-helices have a very small bandgap energy, compared to that of the bulk selenium chain. We foresee a new branch of fundamental metal-insulator transitions caused by the nanospace, thus paving the way toward future applications of non-metallic sulfur and/or selenium as a conducting nanowire.
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