扭转对碳纳米管束热物性的影响

Thermal Conductivity of the Twisted Carbon Nanotube Bundle

采用非平衡分子动力学方法(NEMD)研究了扭转对碳纳米管(CNT)管束热导率的影响。CNT管束由7根(10,10) CNT组成。通过对CNT管束施加不同程度扭转,结果表明CNT管束热导率随着扭转程度增大迅速下降。采用T形法测量了扭转前后CNT管束热导率随温度的变化,实验结果与模拟预测趋势吻合。声子谱和拉曼光谱的结果表明扭转对原结构的破坏,结构有序性降低造成声子软化,最终导致了热导率的下降。

Nonequilibrium molecular dynamics(NEMD) is used to study the thermal conductivity of the twisted carbon nanotube(CNT) bundle which consists of seven(10,10) CNTs.The results show that the thermal conductivity of the bundle decreases rapidly as the twist level increases.Meanwhile,the T-type method is used to measure the thermal conductivity of the same CNT bundle before and after twisting.The experimental results follow the similar trend as the simulated predictions.Combined with the results of the density state of phonon and the Raman spectroscopy,we suggest that the twist reduces structural order,causes phonon softening,and finally leads to the thermal conductivity reduction.