Molecular dynamics study of effects of intertube spacing on sliding behaviors of multi-walled carbon nanotube

The effects of intertube spacing, tube length and wall numbers on the sliding behaviors of multi-walled carbon nanotubes (MWCNTs) are investigated using molecular dynamics (MD) simulation method. The interaction between carbon atoms is modeled using the second-generation reactive empirical bond-order potential coupled with the Lennard-Jones potential. The simulations indicate that, regardless of tube length and wall numbers, small intertube spacing of MWCNT can provides an effective channel for load transfer between tubes, and permits mechanical participation of walls. The results also show that the sliding behaviors of MWCNT are strongly dependent of tube length and wall numbers, especially MWCNT with small intertube spacing. It is observed that small intertube spacing of triple-walled carbon nanotube (TWCNT) result in the formation of intertube sp3 bonds during pullout process. The general conclusions derived from this work may be of importance in devising high-performance carbon nanotube (CNT) composites.

Research highlights
► The effect of wall numbers on the sliding behaviors of MWCNTs is very significant, especially MWCNTs with small intertube spacing.
► Small intertube spacing of MWCNT can provides an effective channel for load transfer between tubes.
► The small intertube spacing causes the formation of sp3 bonds on surface of middle tube during pullout process.