Significant decrease in thermal conductivity of multi-walled carbon nanotube induced by inter-wall van der Waals interactions

• Significant decrease in thermal conductivity of multi-walled carbon nanotube induced by inter-wall interactions.
• The thermal conductivity of the inner tube is increased significantly due to protected by outer tube.
• The outer tube plays a dominant role in heat energy transfer in multi-walled carbon nanotube.

The thermal transport properties of multi-walled carbon nanotubes (MWCNTs) were investigated by using non-equilibrium molecular dynamics simulation. The results show that the thermal conductivity of MWCNTs decreases significantly comparing to that of single-walled carbon nanotubes (SWCNTs) due to the inter-wall van der Waals interactions. The more interesting is a fact that the thermal conductance of MWCNTs is significantly greater than the thermal conductance summation of each SWCNTs. This is because the thermal conductance of a carbon nanotube protected by an outer tube is much larger than that of one that is not protected. Moreover, we also studied the thermal flux distribution of MWCNTs, and found that the outer tube plays a dominant role in heat energy transfer.