Sheet, graphitic

Large clusters of carbon atoms have been studied with ab initio calculations using basis sets of double-C quality. Planar, single-sheet graphite fragments with 6 - 54 atoms were investigated, as well as the spherical "Buckminsterfullerene ... 

The HOMO and LUMO orbital energies seem to converge towards a value of about 4 eV, which would be an estimate of the work function for single sheet graphite. This is in reasonable agreement with the work function of 4.9 eV experimentally found for bulk graphite(58). 

Figure 2. ST0-3G restricted Hartree-Fock SCF energies per C atom of representative fullerenes relative to that calculated for single sheet graphite from the work of Strout el at. (1992). F/atom = 3071/JVC.

Research in graphite intercalates has paved the way for significant current interest in intercalation compounds of the fullerenes (Box 7.1) and carbon nanotubes, which represent wrapped up versions of graphite sheets. Graphite intercalation compounds have been prepared with intercalated fullerenes and nanotubes. We will return to carbon nanotube chemistry in Chapter 15. 

R. Hagiwara, M. Lerner and N. Bartlett, The Preparation of Planar-sheet Graphite Fluorides C F with x < 2, J. Chem. Soc. Chem. Comm. (1989) 573-574. 

Intermolecular forces [Mt Chapter 11] hold the sheets together. Because of the delocalization of the electrons in the extended network of p orbitals perpendicular to the graphite sheet, graphite... 

One of the most estabhshed is the machining of the graphite sheet. Graphite is electrically conductive and reasonably easy to machine. It also has a low density, less than that for any metal that might be considered suitable. Fuel cell stacks made in this way have achieved a competitive power density. However, they have three major disadvantages ... 

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