摘要
采用反向非平衡分子动力学方法模拟研究了300 K下(10,10)单壁碳纳米管的热导率随管长和氮掺杂浓度的变化规律。结果表明:单壁碳纳米管的热导率随管长增加呈线性升高,管长从10 nm增加到100 nm时热导率升高了近5倍,但升高速率逐渐减缓,这是由于管长在增加过程中逐渐接近声子平均自由程大小,声子传热由弹道输运向扩散输运转变所导致;随着氮掺杂缺陷浓度的增加,单壁碳纳米管的热导率先急剧下降后趋于稳定,热导率先急剧下降与管内声子平均自由程的减小有关,而后热导率趋于稳定是由于氮原子的声子模式在声子传热中占主导地位。
The change law of the thermal conductivity of(10,10)single-walled carbon nanotube varying with tube length and nitrogen substitutional doping concentration at 300 K is studied by reverse non-equilibrium molecular dynamics simulation.The simulation results show that the thermal conductivity of single-walled carbon nanotube increases linearly with the increase of the tube length.The thermal conductivity increases by almost five times as the tube length varies from 10 nm to 100 nm,but the increase rate decreases tardily.It shows that the tube length gradually approaches the size of the phonon mean free path during the increase,and the phonon heat transfer process changes from the ballistic transport to the diffusive transport.The study shows that the thermal conductivity first drops sharply and then approaches to constant.The former is a result of the decrease of the phonon mean free path in nanotube,and the latter is because the phonon mode of the nitrogen atoms dominates the phonon heat transfer.
作者
邵钶
刘远超
钟建斌
邹玉
黄志东
SHAO Ke;LIU Yuanchao;ZHONG Jianbin;ZOU Yu;HUANG Zhidong(School of Mechanical Engineering,Beijing Institute of Petrochemical Technology)
出处
《北京石油化工学院学报》
2020年第3期21-25,共5页
Journal of Beijing Institute of Petrochemical Technology
基金
国家自然科学基金资助项目(51106012)
2019年辽宁省高等学校创新人才支持计划(LR2019036)。
关键词
管长
氮掺杂
单壁碳纳米管
热导率
分子动力学模拟
tube length
nitrogen substitutional doping
single-walled carbon nanotube
thermal conductivity
molecular dynamics simulation
