Journal ArticleDOI
Helical microtubules of graphitic carbon
TLDR
Iijima et al. as mentioned in this paper reported the preparation of a new type of finite carbon structure consisting of needle-like tubes, which were produced using an arc-discharge evaporation method similar to that used for fullerene synthesis.Abstract:
THE synthesis of molecular carbon structures in the form of C60 and other fullerenes1 has stimulated intense interest in the structures accessible to graphitic carbon sheets. Here I report the preparation of a new type of finite carbon structure consisting of needle-like tubes. Produced using an arc-discharge evaporation method similar to that used for fullerene synthesis, the needles grow at the negative end of the electrode used for the arc discharge. Electron microscopy reveals that each needle comprises coaxial tubes of graphitic sheets, ranging in number from 2 up to about 50. On each tube the carbon-atom hexagons are arranged in a helical fashion about the needle axis. The helical pitch varies from needle to needle and from tube to tube within a single needle. It appears that this helical structure may aid the growth process. The formation of these needles, ranging from a few to a few tens of nanometres in diameter, suggests that engineering of carbon structures should be possible on scales considerably greater than those relevant to the fullerenes. On 7 November 1991, Sumio Iijima announced in Nature the preparation of nanometre-size, needle-like tubes of carbon — now familiar as 'nanotubes'. Used in microelectronic circuitry and microscopy, and as a tool to test quantum mechanics and model biological systems, nanotubes seem to have unlimited potential.read more
Citations
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Journal ArticleDOI
Cognitive radio: brain-empowered wireless communications
TL;DR: Following the discussion of interference temperature as a new metric for the quantification and management of interference, the paper addresses three fundamental cognitive tasks: radio-scene analysis, channel-state estimation and predictive modeling, and the emergent behavior of cognitive radio.
Journal ArticleDOI
Two-dimensional atomic crystals
Kostya S. Novoselov,Da Jiang,Fred Schedin,Timothy J. Booth,V. V. Khotkevich,Sergey V. Morozov,Andre K. Geim +6 more
TL;DR: By using micromechanical cleavage, a variety of 2D crystals including single layers of boron nitride, graphite, several dichalcogenides, and complex oxides are prepared and studied.
Journal ArticleDOI
Single-shell carbon nanotubes of 1-nm diameter
Sumio Iijima,Toshinari Ichihashi +1 more
TL;DR: In this article, the authors reported the synthesis of abundant single-shell tubes with diameters of about one nanometre, whereas the multi-shell nanotubes are formed on the carbon cathode.
Journal ArticleDOI
Chemistry and properties of nanocrystals of different shapes.
TL;DR: The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties are equally important.
Journal ArticleDOI
Removal of heavy metal ions from wastewaters: A review
Fenglian Fu,Qi Wang +1 more
TL;DR: It is evident from the literature survey articles that ion-exchange, adsorption and membrane filtration are the most frequently studied for the treatment of heavy metal wastewater.
References
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Journal ArticleDOI
C 60 : Buckminsterfullerene
Harold W. Kroto,Harold W. Kroto,James R. Heath,Sean C. O'Brien,Robert F. Curl,Richard E. Smalley +5 more
TL;DR: In this article, the authors proposed a truncated icosahedron, a polygon with 60 vertices and 32 faces, 12 of which are pentagonal and 20 hexagonal.
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Solid C60: a new form of carbon
TL;DR: In this article, a new form of pure, solid carbon has been synthesized consisting of a somewhat disordered hexagonal close packing of soccer-ball-shaped C60 molecules.
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Filamentous growth of carbon through benzene decomposition
TL;DR: Carbon fibres have been prepared by pyrolysing a mixture of benzene and hydrogen at about 1100°C and have been studied by high resolution electron microscopy.
Journal ArticleDOI
Cohesive mechanism and energy bands of solid C60.
Susumu Saito,Atsushi Oshiyama +1 more
TL;DR: In this paper, the authors present microscopic total energy calculations which provide a cohesive property and electronic structures of a new form of solid carbon, the face-centered-cubic crystal (fcc ${\mathrm{C}}_{60}$).
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Growth, Structure, and Properties of Graphite Whiskers
TL;DR: Graphite whiskers have been grown in a dc arc under a pressure of 92 atmospheres of argon and at 3900°K as discussed by the authors, with recoverable lengths up to 3 cm. They are embedded in a solid matrix of graphite which builds up by diffusion of carbon vapor from the positive to the negative electrode.