Energetics carbon clusters

Several proposals have been put forward to account for the formation of C 0F and the other fullerenes. Before reviewing these proposals, it seems appropriate to consider the key observations about fullerene synthesis, the kinds of carbon clusters possible, their energetics, and the thermodynamic and kinetics of carbon clustering. 

Orden, A.V. Saykally, R.J. Small carbon clusters, spectroscopy, structure and energetics. Chem. Rev. 1998, 98. 2313-2357. 

Gaumet, J.J. Wakisaka, A. Shimizu, Y. Tamori, Y. Energetics for carbon clusters produced directly by laser vaporization of graphite dependence on laser power and wavelength. J. Chem. Soc. Faraday Trans. 1993, 59(11), 1667-1670. 

The molecular state of the material at CJ conditions, a critical question to the energetic materials community, is very hard to determine experimentally. Our results show that under conditions near the C-J point (p = 2.11 g/cm and T = 3000 K), a significant amount of the C atoms cluster into a condensed phase. (The size and time-scales of our simulations only allow for the initial stages of carbon clustering to be observed.) Furthermore, at these conditions, we can clearly identify molecules with relatively long mean lifetimes (several bond vibrations) the mean lifetime of Nz molecules is hundreds of picosenconds, and those of HzO and CO2 are of the order of tens of picoseconds. 

Van Orden, A., Saykally, R. Small Carbon Clusters Spectroscopy, Structure, and Energetics, Chem. Rev. 98(1998) 2313-2357. 

The carbon structures formed under ion implantation reinforce the polymer surface and result in a drastic increase in its hardness (Fig. 4). These carbon-rich structures, with sizes ranging up to 40 nm in the case of energetic ion implantation [34], were found to be the aggregates of much smaller carbon clusters several nanometers in size [34,54]. The hardness of the carbonaceous phase produced by ion implantation does not depend directly on the concentration of sp sites (the... 

The formation of the carbon clusters and the network formed by the clusters is a consequence of the interactions between energetic atoms in the collision spike. The internal structure of the clusters is determined by turbulent mass flow inside the collision spike and subsequent thermal quenching. 

Blais, N.C. (1987), Real-Time Analysis of HNS Detonation Products Carbon Clusters, J. Energetic Materials V6, p. 255. 

Sokolova, S., Liichow, A., Anderson, J. B. (2000). Energetics of carbon clusters C20 from allelectron quantum monte carlo calculations. Chemical Physics Letters, 323(3-4), 229-233. 

A second type of cluster emission involves molecular species which can be as simple as carbon monoxide or as complicated as the dodecanucleotide mentioned above. In the first case, the CO bond strength is 11 eV, but the interaction with the surface is only about 1 eV. Calculations indicate that this energy difference is sufficient to allow ejection of CO molecules, although 15 percent of them can be dissociated by the ion beam or by energetic metal atoms (6). For such molecular systems it is easy to infer the original atomic configurations of the molecule and to determine the... 

Gas-phase nucleation Flame synthesis of particles (e.g., carbon black, silica) cluster formation in chemical vapor deposition manufacture of high-purity silicon cluster structure and energetics plasma synthesis of refractory materials and coatings. 

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