The effects of encapsulating C_(60) fullerenes on the bending flexibility of carbon nanotubes

摘要

We investigate the bending flexibility of carbon nanotubes (CNTs) with encapsulated C_(60) fullerenes, using molecular dynamics (MD) simulations. Our simulations on the bending of the fully ((C_(60))_(12)@(10, 10)) and,partially ((C_(60))_(10)@(10, 10)) filled peapods show an 18 and 6.3 percent increase of the flexural rigidity, and a 45 and 11 percent increase of the buckling strength, respectively, compared to the empty (10, 10) CNT. What is characteristically different for the peapod from the empty CNT is the presence of a transitional region in the loading process that proceeds to the onset of buckling. Within this transitional region, the interaction between the encapsulated fullerenes and the hosting CNT leads to an unusual configuration of the peapod, in which there are ripples along the inner arc of the bent peapod. The transition region in the partially filled peapod is short compared with the fully filled peapod. This is mainly caused by the axial motion of C_(60) fullerenes, especially after the appearance of the small ripple. The rippling configuration has been reported previously in the bending of multi-walled CNTs, where it emerges after the critical bending angle. However, in the present case, the peapod remains perfectly elastic in this transitional region until buckling takes place.