How interlayer twist angles affect thermal conduction of double-walled nanotubes: A non-equilibrium molecular dynamics study

Carbon nanotubes have been widely considered as a promising low dimensional material in microelectronic, chemical and biological applications. Moreover, assisted by the boron nitride nanotube, the combined nanotube has better strength and thermal stability. In these multi-walled nanotubes, the interlayer twist angle could affect the thermal conductivity. In our previous studies, effects of the interlayer twist angle on thermal conductivity of multilayer graphene have been carefully investigated. However, few studies focus on the thermal conductivity on multi-walled nanotubes with interlayer twist angles. Such knowledge gap poses challenges to their potential applications. Therefore, in this study, the thermal conductivity of 4 types of nanotubes, including double-walled carbon nanotube, double-walled boron nitride nanotube, boron nitride nanotube coaxially wrapped by carbon nanotube and carbon nanotube coaxially wrapped by boron nitride nanotube, is investigated based on the non-equilibrium molecular dynamics simulation. The size effect is firstly evaluated, and then, five different twisted structures according to the chiral angle of the inner tube were taken into consideration at five different temperatures. Moreover, the phonon vibrational density of state was estimated to analyze the underlying mechanisms during the thermal conduction. The results indicate that the interlayer twist angle affects the thermal conductivity. With a constant chiral angle of the outer tube, the thermal conductivity increases as the chiral angle of the inner tube increases, and the maximum value of the thermal conductivity can be obtained when the chiral angle of the inner tube is 30.00°. The observation would guide to study thermal transport in the twisted low dimensional structures. © 2020