含有Stone-Wales缺陷的碳纳米管的热导率模拟

THERMAL CONDUCTIVITY OF CARBON NANOTUBES WITH STONE-WALES DEFECTS

本文以Stone-Wales(SW)缺陷对碳纳米管热导率的影响为研究内容,采用非平衡态分子动力方法,模拟计算存在一个或多个SW缺陷的碳纳米管的轴向温度分布和热导率,并与无缺陷完整碳纳米管进行比较,开展缺陷效应分析,考察了缺陷浓度、碳管长度、碳管手性以及环境温度等因素的影响。模拟结果表明,由于缺陷存在,碳管轴向温度分布在缺陷处产生非线性的间断性跳跃,局部热阻增大。相对完整无缺陷碳管,含有SW缺陷的碳管热导率显著下降;随着缺陷数目的增加,碳管热导率下降的幅度增大。无论是否存在缺陷,锯齿型碳管的热导率通常小于扶手椅型的碳管,而长碳管的热导率通常大于短碳管;相对于锯齿型/长碳管,扶手椅型碳管/短碳管对SW缺陷更为敏感。

The thermal conductivity of carbon nanotubes（CNTs） with Stone-Wales（SW） defects is investigated using non-equilibrium molecular dynamics method.The axial temperature and the thermal conductivity of the CNTs with one or more SW defects are simulated and compared with the perfect ones.The influences of the defect density,the length,the chirality of tubes and the ambient temperature are analyzed.It is demonstrated that a sharp jump in the temperature profile and a higher local thermal resistance occur at defect positions,which resulting in lower values for the thermal conductivity of nanotube with defects.As the number of SW defects increase,the thermal conductivity decreases;no matter if with defects,the thermal conductivity of armchair/longer CNTs is bigger than that of the zigzag/shorter ones;the armchair/shorter CNTs is more sensitive to the defect than the zigzag/longer ones.