Encapsulation of methane in nanotube bundles

In this study, the authors investigate methane storage, and in particular the binding and suction energies of methane in (8, 8) carbon and (10, 10) silicon nanotube bundles. Employing the Lennard-Jones potential together with the continuous approximation, they determine the interaction energy, molecular force and suction energy for a methane molecule in nanotube bundles. The authors approximate the methane molecule by assuming that the four hydrogen atoms are smeared over a spherical surface of a certain radius with the carbon atom located at the centre of the sphere. This is an important assumption in terms of simplifying the calculation, since with this model the particular orientations of the hydrogen atoms do not enter the calculation. Their results indicate that silicon nano structures may be superior candidates for methane storage at high temperatures, particularly in the range 200-400 K.