Highly ordered carbons

J. Li, C. Papadopoulos, and J. Xu, Highly-ordered carbon nanotube arrays for electronics applications. 

Carbon nanotubes, as graphene and graphite, are highly ordered carbon phases. However, a separate line can be drawn for historical development of disordered carbon phases among them is an amorphous carbon (am-C). In it, strong bonding between carbons did not allow for completely chaotic distribution of carbon atoms in solid-state phase. Instead, amorphous carbon exhibits random distribution of three possible coordinations of carbon atoms in a planar sp, tetrahedral sp and... 

Xia, Z., Curtin, W.A., Sheldon, B.W., Fracture toughness of highly ordered carbon nanotube/alumina nanocomposites, J. Eng. Mater. Tech., 2004, 126(3) 238. 

Pyrolytic graphite. Pyrolytic graphite is produced by pyrolysis of hydrocarbons under reduced pressure to give a deposit of highly ordered carbon crys-... 

Ryoo, R., Joo, S.H., and Jun, S. Synthesis of highly ordered carbon molecular sieves via template-mediated structural transformation. J. Phys. Chem. B 103, 1999 7743-7746. 

Li, X, Papadopoulos, C., Xu, J. M., and Moskovits, M., Highly ordered carbon nanotube arrays for electronic applications. Appl. Phys. Lett. 75, 367 (1999). 

C, are called hard carbons. This change from precursor to a random carbon, after carbonization, to a highly ordered carbon after graphitization, is illustrated in Figure 2. 

R. Ryoo, S.H. Joo, and S. Jun, Synthesis of Highly Ordered Carbon Molecular Sieves via Template-mediated Structural Transformation. J. Phys. Chem. B, 1999, 103, 7743-7746. 

Simonov et al. [260] attempted to find common ground in the literature data and suggested a correlation dependence of the corrosion rate on substructural characteristics of carbon materials determined from x-ray analysis. This is represented in Figure 12.8, which shows that specific corrosion rate increases with the substructural parameter, defined as (/ooz/ to) x dooi/Lc (these are defined in Section 12.2). This empirical parameter approaches zero for highly ordered carbon materials, since 1002, ho, and doo2 are constant and h is large but increases for amorphous carbons. 

N. Puech, C. Blanc, E. Grelet, C. Zamora-ledezma, M. Maugey, C. Zakri, E. Anglaret, P. Poulin, Highly ordered carbon nanotubes nematic liquid crystals. J. Phys. Chem. C 115, 3272-3278 (2011)... 

Fig. 2.14 Electron microscopy images of the carbon film, a Z-contrast image of the iaige-scale homogeneous carbon film in a 4 x 3 mm area. The scale bar is 1 mm. b Z-contrast image showing details of the highly ordered carbon structure. The scale bar is 300 nm. c HR-SEM image of the surface of the carbon film with uniform hexagonal pore array. The pore size is 33.7 2.5 nm, and the waU thickness is 9.0 1.1 nm. The scale bar is 100 nm. d SEM image of the film cross section, which exhibits all parallel straight channels perpendicular to the film surface. The scale bar is 100 nm. Reproduced from Ref. [49] by permission of John Wiley Sons Ltd...

Park, C., Keane, M. (2001). Controlled Growth of Highly Ordered Carbon Nanofibers from Y Zeolite Supported Nickel Catalysts. I mgmujj 17, 8386-83%. 

Besides the crystalline and porous structure, an active carbon surface has a chemical structure as well. The adsorption capacity of active carbons is determined by their physical or porous structure but is strongly influenced by the chemical structure. The decisive component of adsorption forces on a highly ordered carbon surface is the dispersive component of the van der Walls forces. In graphites that have a highly ordered crystalline surface, the adsorption is determined mainly by the dispersion component due to London forces. In the case of active carbons, however, the disturbances in the elementary microcrystalline structure, due to the presence of imperfect or partially burnt graphitic layers in the crystallites, causes a variation in the arrangement of electron clouds in the carbon skeleton and results in the creation of unpaired electrons and incompletely saturated valences, and this influences the adsorption properties of active carbons, especially for polar and polarizable compounds. 

Recently, we presented a new approach for the fabrication of highly ordered carbonized nanostructured thin films involving the ion beam treatment of self-assembled BCP... 

Figure 9.6 Formation of a highly ordered carbon nanotube assembly, (a) and (b) TEM images of the sheet structure (c) periodic patterns in panel (b) extracted through Fourier translation (d) TEM images of the composite without crosslinker (e) illustration of the crosslinking reaction. 

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