巻号一覧
2013 巻 (2013)
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2013 巻, 258 号
選択された号の論文の12件中1～12を表示しています
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解説
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川口 雅之原稿種別: 解説
2013 年 2013 巻 258 号 p. 165-170
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありCarbonaceous materials of the boron/carbon/nitrogen (B/C/N) system and carbon/nitrogen (C/N) system have been reviewed. A material with a composition BC2N made by CVD had the graphite-like layer structure. Sodium was intercalated into and de-intercalated out of BC2N by an electrochemical method, and the material can be used as an anode of sodium ion batteries. Magnesium was intercalated into BC2N by vapor phase reaction. The intercalations can be explained by a relation between the ionization potentials of metals and electron affinities of the host materials. C/N materials have a high hardness, are photoluminescent and exhibit reversible ion adsorption/desorption in solution. These properties depend on composition, chemical bonding and structure, and should be useful in wide fields.抄録全体を表示PDF形式でダウンロード (824K) -
児玉 昌也原稿種別: 解説
2013 年 2013 巻 258 号 p. 171-178
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありNovel nitrogen-enriched carbon materials prepared from heterocyclic hydrocarbons containing nitrogen atoms by an ordinary heat treatment method are reviewed. On account of the nitrogen atoms in the starting hydrocarbons, a certain amount (5-45 wt%) of nitrogen remained in the resulting carbons. In addition, thin film, layered, mesoporous and fibrous structures were successfully introduced into the nitrogen-enriched carbon body using selective precursors and the template method. The obtained carbons exhibited a unique electrochemical capacitor performance such as high specific capacitance and do not appear to follow the normal relationship between electrolyte ions and pore structure on an electrode surface. These features can be attributed to the electrochemical interaction of nitrogen in the carbon network with electrolyte ions. Although some inexplicable anomalies remain, these nitrogen-enriched carbon materials have high promise as an electrochemical capacitor electrode material.抄録全体を表示PDF形式でダウンロード (2027K) -
高井 和之原稿種別: 解説
2013 年 2013 巻 258 号 p. 179-186
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありGraphene as a fundamental building block for carbon materials has attracted great attention over the last decade because of its novel properties. The peculiar electronic properties of graphene intrinsically originate from the geometry of its honeycomb lattice. In addition, the pure two-dimensional structure, where all carbon atoms lie in the surface, gives graphene extreme sensitivity to the influence of external chemical species, where the electronic properties are easily tuned through chemical modification. In this review, the electronic properties of graphene are discussed in terms of the influence of the topological and chemical modification. This promises to be a promising strategy to understand the fundamental properties of carbon materials in various forms.抄録全体を表示PDF形式でダウンロード (1425K)
論文
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Yutaka Kaburagi, Miu Ohoyama, Emi Shindo, Akira Yoshida, Norio Iwashit ...原稿種別: Research Paper
2013 年 2013 巻 258 号 p. 187-194
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル フリーCommercially available pure cellulose paste of plant origin composed of nanofibrils was dispersed in ethanol or distilled water, and sheets made of the nanofibrils were prepared by filtration. The sheets were carbonized and then heat-treated at temperatures between 2400 and 3200 °C at atmospheric pressure, and the original paste was also carbonized and heat-treated at 3100 °C. The diameter of the cellulose nanofibrils was found to be 30-300 nm in the sheets, while no fibrous texture was observed in the original paste. Structural order of the carbonized sheets improved with increasing heat treatment temperature, and was especially remarkable for the sheet derived from nanofibrils dispersed in ethanol, though turbostratic components were observed even for the sheet heat-treated at 3200 °C. On the other hand, the 3100 °C-treated paste exhibited a typical turbostratic structure. The development of graphite structure in the carbon sheets is probably attributed to surface graphitization, the same as the graphitization of the carbonized sheets prepared from bacteria cellulose nanofibers by heat treatment at high temperatures reported previously. The structural development of the present heat-treated sheets was less than that of the heat-treated sheets prepared from bacteria cellulose nanofibers. The result could be attributed to the thicker diameters and lower crystallinity of the present precursor nanofibrils compared to those of the bacteria cellulose nanofibers.抄録全体を表示PDF形式でダウンロード (2850K) -
平 成一, 山本 翔太郎, 小嶋 夏子, 加納 博文, 大場 友則原稿種別: 論文
2013 年 2013 巻 258 号 p. 195-200
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル フリーWater vapor adsorption on porous carbons has been actively studied because of its importance in various applications and basic science. However, the unique behavior and structure of water in carbon nanospaces have still been remained unclear. Carbon nanotubes inherently have rather restricted one-dimensional nanospaces and thus, force the adsorbed water to be aligned in them. The structure of water adsorbed in those nanospaces is ice-like even at ambient temperature. In this paper, we show the water structures in two-different single wall carbon nanotubes (CNTs) with average CNT diameters of 1.1 (narrow) and 2.5 (wide) nm at 260-300 K, which were evaluated by using in situ synchrotron X-ray diffraction (XRD). The water structures in the both CNTs were nano-ice-like forms at 300 K rather than a liquid-like. The ice-like structure in the wide CNTs was developed with decreasing temperature, although even at 260 K, sharp ice peaks were not observed in the XRD pattern. On the other hand, in the narrow CNTs, the water structure was gradually transformed from an ice-like form to a liquid-like form with decreasing temperature to 260 K. The structure transformation of solid-to-liquid with decreasing temperature is due to the fact that the highly restricted nanospaces obstruct the formation of ice-like clusters and/or hydrogen bonds. The anomalous structure transformation in both CNTs could be a clue to reveal one-dimensional water behavior in CNTs.抄録全体を表示PDF形式でダウンロード (1076K)
解説
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松下 哲士, 京谷 陸征, 赤木 和夫原稿種別: 解説
2013 年 2013 巻 258 号 p. 201-209
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありOne-handed helical graphite films with a structure controlled by that of the original iodine-doped helical polyacetylene (H-PA) films were prepared using the recently developed morphology-retaining carbonization method. The fibrillar structure of the H-PA film remains unchanged even after carbonization at 800 °C. The weight loss of the film due to carbonization was very small; only 10-29% of the weight of the film before doping was lost. Furthermore, the graphite film prepared by subsequent heating at 2600 °C retained the same structure as that of the precursor films. The screw direction, degree of twist, and vertical or horizontal alignment of the helical graphite film were well controlled by changing the sense and pitch of the helix, and the orientation of the chiral nematic liquid crystal (N*-LC) used as an asymmetric LC reaction field. The important potential of these graphite films is exemplified in their electrical properties. The horizontally aligned helical graphite film exhibits an increase in electrical conductivity compared to the nonaligned one. The aligned helical graphite film also shows an electrical anisotropy in which conductivity parallel to the helical axis of the fibril bundle is higher than that perpendicular to the axis.抄録全体を表示PDF形式でダウンロード (11538K) -
高口 豊原稿種別: 解説
2013 年 2013 巻 258 号 p. 210-215
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありA water-soluble supramolecular nanohybrids was obtained by sonication and centrifugation of a water dispersion of fullerodendron and single-walled carbon nanotubes (SWCNTs). A coaxial nanocable structure was confirmed by photoluminescence spectra, AFM, and TEM, that showed a SWCNT core and fullerodendron shell. Surface functional groups of the hybrid can interact to form compounds with various inorganic materials such as CaCO3 and SiO2. SWCNT/fullerodendron/CaCO3 fabricated through biomimetic mineralization showed unique core-shell microsphere structures while SWCNT/fullerodendron/SiO2 still had a coaxial nanocable structure. Because of a photofunctional interface, SWCNT/fullerodendron/SiO2 hybrids have a high photocatalytic activity (ϕ=0.31) for the evolution of hydrogen from water under irradiation with visible light (450 nm). A single component photocatalytic system was constructed by introducing Pt complexes into SWCNT/fullerodendron supramolecular nanocomposite.抄録全体を表示PDF形式でダウンロード (2726K)
連載講座
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鏑木 裕原稿種別: 連載講座
2013 年 2013 巻 258 号 p. 216-229
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありPDF形式でダウンロード (3263K)
学位論文紹介
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竹内 紗綾原稿種別: 学位論文紹介
2013 年 2013 巻 258 号 p. 230-231
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありリチウムイオン電池は実用化されている二次電池のなかでも高いエネルギー密度を有しているが，用途の広がりとともにさらなる高性能化が求められている。そこで本研究では，リチウムイオン電池を超えるカルシウムイオン電池の黒鉛負極に関する基礎的研究とリチウムイオン電池の高性能化に資する黒鉛負極に適合した高性能電解液の開発を行った。
リチウムイオン電池負極においてキャリアを1価のリチウムイオンから2価のカチオンに変えることができれば，容量は2倍になる。2価カチオンの黒鉛層間化合物としては化学的には合成が可能なカルシウム–黒鉛層間化合物があるが，電気化学的な挿入反応はいまだに報告例がないため電気化学的合成のための基礎的研究を行った。
リチウムイオン電池の電気自動車への搭載に関しては，寒冷地では電解液に用いられている炭酸エチレン (EC) が低温で固化などによりイオン伝導性の低下を起こすことや有機溶媒であるため可燃性が問題点として挙げられる。電解液の選択により，低温特性や安全性を改善することは可能であるが，EC以外の有機溶媒中ではリチウムイオンの黒鉛への挿入反応は通常進行しない。しかし，EC以外の有機溶媒中でもリチウムイオン濃度の増加によるリチウムイオンの溶媒和数の低下により，リチウムイオンの挿入が可能になることが報告されている。そこで，リチウムイオンよりも強いルイス酸性を有するカルシウムイオンを用いて溶媒和構造の制御を行うことができれば，EC系電解液に替わるリチウムイオン濃度の増加を必要としない新しい高性能電解液の設計指針が得られると考え，高性能電解液の開発を行った。抄録全体を表示PDF形式でダウンロード (296K) -
Shiori Kubo原稿種別: Recent Doctoral Thesis
2013 年 2013 巻 258 号 p. 232-233
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありThis thesis presents the production of nanostructured carbonaceous materials via a combined hydrothermal carbonisation (HTC)– nanocasting technique with the particular focus on the generation of well-defined pore structures/geometries. Firstly, inorganic sacrificial templates such as anodic alumina membranes and mesoporous silicas are used as hard templates to yield tubular carbons and mesoporous carbonaceous spheres, whilst, importantly, their surfaces are decorated with tuneable oxygenated surface functionalities. Secondly, complementary to this so called “hard templating” approach, a combined HTC–soft templating route for the direct synthesis of ordered porous carbonaceous materials is demonstrated. The use of PEO-PPO-PEO triblock copolymer as a soft template allows the successful production of single crystal–like carbonaceous particles with Im3m pore symmetry, whilst d-fructose represents a useful carbon precursor as the HTC process can be performed at a reduced temperature of 130 °C, thus allowing access to stable micellular phase. Throughout the thesis, the materials are characterised carefully mainly by electron microscopy, small/wide-angle X-ray scattering, N2/CO2 gas sorption and FTIR and Raman spectroscopy. The presented synthetic routes provide access to nanostructured carbonaceous materials with rich surface chemistry through a low-temperature, aqueous procedure using inexpensive and renewable carbon precursors. The obtained materials are of potential interest as candidates in chromatography, electrochemistry or drug delivery. In the following section, summary of each chapter in the thesis is presented.抄録全体を表示PDF形式でダウンロード (248K) -
小田原 玄樹原稿種別: 学位論文紹介
2013 年 2013 巻 258 号 p. 234-239
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありグラフェンはグラファイトのハニカム格子1枚の炭素膜として定義され，近年，新しい炭素材料として注目されている。
本博士論文では，従来の研究では得られなかったサブミクロンからミリスケールの空間分解能で，グラフェン膜の成長をその場観察することによって，いままでの研究成果に基づく議論の妥当性を検証するとともに，実用を念頭においたグラフェン製造新技術の確立を目指している。具体的に述べると，過去の研究の表面測定手段であるオージェ電子分光 (AES)，X線光電子分光 (XPS)，紫外線光電子分光 (UPS)，低エネルギー電子回折 (LEED)，高分解電子エネルギー損失分光 (HREELS) などにより得たデータは，巨視的なスケールで平均化された情報に限られおり，逆に，走査トンネル顕微鏡 (STM) や原子間力顕微鏡 (AFM) では極めて狭いナノメーター領域の情報のみの提供に限られていた。本研究では実用上重要であるメゾスコピックスケールの情報を取得するために，最近，開発が進んでいる低エネルギー電子顕微鏡 (LEEM) を駆使し，グラフェン成長過程を直接その場観察して，学術面および実用面でのいくつかの貴重な知見を得ている。さらに，LEEMの採用により，いままでにない明るい顕微観察が可能となり，ミリ秒単位の時間分解の実時間で成長が見えるようになり，従来の研究成果から予想されるいくつかの現象（カーペット状成長，シングルドメイン融合など）に明瞭な実験的根拠を提供している。抄録全体を表示PDF形式でダウンロード (348K)
談話室
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大澤 映二原稿種別: 談話室
2013 年 2013 巻 258 号 p. 236-239
発行日: 2013/06/15
公開日: 2013/07/15
ジャーナル 認証ありPDF形式でダウンロード (469K)
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