Thermal transport properties of graphyne nanotube and carbon nanotube hybrid structure: nonequilibrium molecular dynamics simulations

By performing nonequilibrium molecular dynamics (NEMD) simulations, a GNT/CNT hybrid structure made by graphyne nanotube (GNT) and carbon nanotube (CNT) has been designed and investigated. The influences of length, percentage of GNT, and tensile strain on the thermal transport properties of GNT/CNT hybrid structure are examined. It reveals that the thermal conductivity of hybrid structure increases linearly with the length. Due to the different phonon properties between GNT and CNT, the thermal conductivity of hybrid structure appears as a sharp drop in comparison with the pure CNT. By controlling the percentage of GNT, this hybrid structure exhibits tunable thermal transport behaviors. Moreover, a dramatically thermal rectification phenomenon is observed when applying a tensile strain along the heat flow direction. As the strain rises from 0.0 to 0.06, the rectification factor increases from 2.62 to 12.94%; however, the thermal conductivities reduce by 23.9 and 16.3% for the heat flow direction from GNT to CNT and the opposite direction, respectively. These findings would provide significant insights into the potential applications of GNT/CNT hybrid material in nanodevices.