Mechanics of nanotubes filled with C60, C36 and C20

The mechanical properties of single-walled nanotubes (SWNTs) filled with small fullerenes (C20, C36 and C60) were investigated using molecular dynamics (MD) simulation. The interaction between carbon atoms was described by a combination of the many-body Brenner potential with a two-body pair potential. We found that below the critical value of the strain, the stress of SWNT increases linearly with the strain and the Young's modulus of certain SWNT with different filling densities is almost the same for small strain. It was also observed that the buckling force, which corresponds to the critical strain, becomes higher as the filling density of SWNT is increased in general. However, in the case of SWNT of larger radius filled with smaller fullerenes, the dependence of the buckling force on the filling density is expected to be different, which was attributive to the long-distance attractive interaction between atoms of fullerene and those of SWNT.