Van der Waals binding to fullerenes to a graphite plane

Abstract

We develop a model that predicts the potential energy function W(R) of a spherical fullerene, CN, near a graphite surface. R is the distance between the fullerene center of mass and the surface. The model is based on summing all the interactions between the C atoms in the fullerene and those on a graphite sheet. The atom-atom potential employed is a Lennard-Jones 12-6 potential with parameters chosen from previous treatments of graphite and of c6O(s). The binding energy is suprisingly large, varying between 15 and 19 kcal/mol for C60 depending on the potential, and scales approximately as N'/*. W(R) is used to determine the force constant and fundamental frequency, as well as the Arrhenius expression A exp(-E,/kT), for desorption d the CN from the graphite surface. This information can be used to determine relative desorption rates as a function of temperature for fullerenes that are more round than cylindrical. We describe and predict the results of a feasible experiment that would measure the temperature-programmed desorption of fullerenes from a graphite surface.

Carbon nanotubes, buckyballs, ropes, and a universal graphitic potential

“…2 This continuum model was also applied to a calculation of the thermal expansion 3 of solid C 60 , to the cohesive and anharmonic properties 4 of solid C 70 , and to fullerene alloys. 5,6 It was also used to analyze the growth of fullerene clusters, 7,8 screw dislocations 9 in solid C 60 , the interaction of C 60 with a graphite surface in which graphene sheets, as well as C 60 molecules, were treated as surfaces with a uniform distribution of centers of the LJ potential 10 and to a study of C 60 stage-one intercalated graphite. 11 Recently, the continuum model has been extended to a calculation of the potential between carbon nanotubes 12 and used to study the vibrational modes in nanotube bundles.…”

Long Range Correlations in Chemical Oscillations

“…Field and Noyes were able to construct a simplified mathematical model [11], now known as the Oregonator, which exhibits oscillatory limit cycles. The model also successfully describes the fascinating features of the complex phenomena seen in the BZ reaction, both temporal, such as excitability [12,13], bistability [14], stirring effects [15,16], quasiperiodicity, and chaos [17,18], and spatial, including traveling waves [19], target and spiral patterns [20,21], scroll rings [22], and their orientation dynamics in advective fields [23]. In our study, we will, in particular review the evidence supporting the presence of long range correlation in this reaction.…”

A model to calculate the average interaction energy and adhesion force between petroleum asphaltenes and some metallic surfaces

“…This scheme relies on the uniform atomic-distribution over the metallic substrate (crystalline array), as discussed elsewhere [14,[17][18][19][20]. Furthermore, a flat metallic surface is assumed.…”

“…5). s −1 is the atomic density over the plane, which is ex- pressed in terms of the atomic volume density n and interplanar distance d p as [16][17][18][19][20] …”