碳纳米管热传导的分子动力学模拟研究

采用改进的经验键序作用势描述碳原子间的相互作用,应用分子动力学方法和Green-Kubo函数计算了碳纳米管的热导率.在模拟中,使用了重叠计算的方法来计算热流相关函数,大大减少了模拟步数.计算结果表明,碳纳米管的热导率以原子间作用力相互做功所引起的热流形式为主;热导率的值随着直径的增加而减小;在室温下,热导率的值随着温度的增加而增加,达到室温后逐渐收敛于定值.计算的单壁碳纳米管热导率在1000W/mK至4000W/mK之间,计算结果与实验结果基本符合. 关键词： 分子动力学 碳纳米管 热导率

Study of thermal conduction of carbon nanotube by molecular dynamics

Based on the molecular dynamics method and improved reactive empirical bond order potential, Green-Kubo function is used to calculate the thermal conductivity of carbon nanotube. The overlapping method is used which shortens the simulation time greatly. The result shows that the most significant contribution to the thermal conductivity is presented by the auto correlation of interactive force of atoms. The thermal conductivity decreases as the tube diameter increases. The thermal conductivity increases as the temperature increases for temperature lower than 300K and converges to a constant when the temperature rises above 300K. The thermal conductivity of the single-walled carbon nanotube ranges from 1000W/mK to 4000W/mK, and the results are in good agreement with the experimental data.