管长和氮掺杂对单壁碳纳米管热导率的影响研究  

Research on the Influence of Tube Length and Nitrogen Substitutional Doping for the Thermal Conductivity of Single-walled Carbon Nanotubes

作　　者：邵钶 刘远超[1] 钟建斌 邹玉[1] 黄志东[2] SHAO Ke;LIU Yuanchao;ZHONG Jianbin;ZOU Yu;HUANG Zhidong(School of Mechanical Engineering,Beijing Institute of Petrochemical Technology)

机构地区：[1]北京石油化工学院机械工程学院,北京102617 [2]辽宁科技学院机械工程学院,辽宁本溪117004

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)。

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.

关 键 词：管长 氮掺杂 单壁碳纳米管 热导率 分子动力学模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]