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Carbon

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Carbon T Takamura, Harbin Institute of Technology, Harbin, China & 2009 Elsevier B.V. All rights reserved. Physical and Chemical Properties of Carbon Families Morphology of Carbon Carbon is solid under ambient temperature and pressure and there are four allotropes: diamond, graphite, nanotubes and fullerenes, and carbynes, and in addition, there are many morphologies including amorphous carbons, glass-like carbons, porous carbons, and so on. The presence of such a wide variety of carbon morphologies is ascribed to the presence of different hybrid atomic/molecular orbitals: sp1, sp2, and sp3. Usually, the binding structure of solid carbon consists of hybridization of sp2 and sp3 orbitals, which form. | Carbon T Takamura Harbin Institute of Technology Harbin China 2009 Elsevier B.V. All rights reserved. Physical and Chemical Properties of Carbon Families Morphology of Carbon Carbon is solid under ambient temperature and pressure and there are four allotropes diamond graphite nanotubes and fullerenes and carbynes and in addition there are many morphologies including amorphous carbons glass-like carbons porous carbons and so on. The presence of such a wide variety of carbon morphologies is ascribed to the presence of different hybrid atomic molecular orbitals sp1 sp2 and sp3. Usually the binding structure of solid carbon consists of hybridization of sp2 and sp3 orbitals which form several different phases and it is difficult to isolate a morphologically pure single phase. Therefore the morphological classification of carbon is not clear but ambiguous. In the following the polymorph will be classified on the basis of the hybrid molecular orbital. 1 sp1 carbyne 2 sp2 graphite isotropic graphite highly oriented graphite carbon nanotube fullerenes 3 Mixture of sp2 and sp3 hard carbon soft carbon carbon black glass-like carbon amorphous carbon activated carbon porous carbon carbon fiber mesophase carbon micro-beads 4 sp3 diamond This article describes a rough outline of all the carbon morphologies based on structure and applications and later on the carbon materials that are used in the field of power sources are explained in detail. Formation and Characteristics of All the Carbon Morphologies Carbyne Usually carbyne is formed as a black powder and the molecular structure is an sp1 polymer carbon allotrope having a chemical formula written as -C C- n or C C n. Basically it may be synthesized by condensation polymerization of acetylene in which the carbon bond configuration is sp1 practically however a convenient preparative method is expressed by eqn I CF2 -CF2- 4nK- -C C- 4nKF I where poly tetrafluoroethylene reacts with potassium metal to form carbyne and potassium .