Graphitic cones

Graphitic cones with sp -hybridized carbon atoms... 

Interestingly, two years after these ideas on graphitic cones were presented at the 7th International Symposium on Novel Aromatic Compounds (Victoria, BC, Canada, July 18-24,1992), and a few months after the apparition of the corresponding paper [14], Ge and Satler from the University of Hawaii [151 reported the experimental observation of cones with the smallest solid angle, formed by folding a single sector with a planar angle of 60° as in Fig. 4. 

Fig. 31. Graphitic cones, possessing different angles, obtained by pyrolytic techniques. (Courtesy of T.W. Ebbesen)...

Figure 3.1 Illustration of carbon nanostructures (a) hexagonal network of carbon (graphene), (b) TEM image of curved graphitic cone, (c) multiwalled carbon nanotube consisting of concentric graphene sheets, and (d) carbon nanoliber composed of stacked graphitic cones at an angle alpha with respect to the axis of the liber. Reprinted with permission from [4,6].

Delmonte, J. Technology of Carbon and Graphite ConE>osites (Van Nostrand Reinhold, New York 1981) pp. 11-14. 

Materials engineering Graphitic cones and polyhedral crystals enable the development of new functional nanomaterials and fillers for nanocomposites. 

Several other types of cones have been reported that are actually composed of cylindrical graphite sheets. The so-called tubular graphite cones (TGCs) (Figure 3.8) have been synthesized on... 

FIGURE 3.9 FESEM images of graphite cones from (a) Gooderham, Ontario, Canada. (Adapted from J. A. Jaszczak et al.. Carbon, 41, 2085, 2003.) (b-d) Graphite cones, scrolls, and tubes from Hackman Valley, Kola Peninsula, Russia. A scroll-type structure is suggested in (b). Some of the Kola cones appear to be hollow, as indicated by a fractured structure (d). (Adapted from S. Dimovski et al.. Biennial Conference on Carbon, American Carbon Society, RI, 2004.)... 

In the previous section, we have seen that, on the basis of their structure, a distinction can be made between the two major classes of graphitic cones. One type has a scroll-helix structure, whereas the second type comprises seamless conical graphene layers stacked over each other along their... 

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