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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。
In this paper, the influence of the Stone-Wales (SW) defect on the thermal conductivity of carbon nanotubes is studied. The non-equilibrium molecular dynamics method is used to simulate the axial temperature distribution and heat of one or more SW-defective carbon nanotubes The conductivity and defect-free intact carbon nanotubes were compared to carry out defect effect analysis. The effects of defect concentration, carbon tube length, carbon nanotube chirality and ambient temperature were investigated. The simulation results show that due to the existence of defects, the axial temperature distribution of carbon nanotubes produces discontinuous jumps at the defects and the local thermal resistance increases. Relatively complete defect-free carbon nanotubes, carbon nanotubes containing SW defects significantly decreased the thermal conductivity; as the number of defects increased, the thermal conductivity of carbon nanotubes decreased. Regardless of whether there are defects, the thermal conductivity of serrated carbon tube is usually less than the armchair carbon tube, and the thermal conductivity of carbon nanotubes is usually greater than the short carbon tube; relative to the serrated / long carbon tube, armchair carbon tube Short carbon tubes are more susceptible to SW defects.