碳纳米管电缆式复合材料的热导率  

Thermal conductivity of carbon nanotube cable type composite

作　　者：唐晶晶[1] 冯妍卉[1,2] 李威[1] 崔柳[1] 张欣欣[1,2] 

机构地区：[1]北京科技大学机械工程学院,北京100083 [2]北京科技大学,冶金工业节能减排北京市重点实验室,北京100083

出　　处：《物理学报》2013年第22期327-332,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50876010;51176011);国家重点基础研究发展计划(批准号:2012CB720404);中央高校基本科研业务费专项资金(批准号:FRF-AS-12-002;FRF-TP-11-001B)资助的课题~~

摘　　要：通过非平衡分子动力学方法,对单壁碳管填充金纳米线的碳纳米管电缆式复合材料开展热导率的模拟分析.采用Tersoff势函数描述碳-碳原子间的相互作用,Lennard-Jones长程作用势描述碳-金原子间的相互作用,嵌入原子势函数描述金-金原子间相互作用.研究结果表明:相同尺寸下,金纳米线的电子热导率相较于空碳管以及电缆式复合材料的声子热导率小很多,对复合材料总热导率的贡献可以忽略;由于管内金纳米线的存在,其与碳管的相互作用使得碳管碳原子倾向于沿着轴向振动,声子间U散射随之减少,声子平均自由程增加,导致复合材料热导率明显大于空碳管,在100—500 K温度范围内高出约20%—45%,但增大幅度随温升呈降低趋势;复合材料热导率随着管长增加而增大,变化趋势和空碳管相似,但其增长幅度更大;复合材料和空碳管的热导率随管径增大而减小,且变化幅度基本一致.For single-wall carbon nanotubes filled with gold nanowires, a kind of carbon nanotube cable type composite material, its ther-mal conductivity is simulated by non-equilibrium molecular dynamics method. The Tersoff potential is employed for C-C bonding interactions, the Lennard-Jones potential for C-Au interactions and the embedded atom method potential for Au-Au interactions. It turns out that the electronic thermal conductivity （ETC） of gold nanowire is much lower than that of the composite with the same size, so the ETC of metal nanowire could be ignored. The carbon atoms tend to vibrate along the axial direction of the tube because of the interaction between gold and carbon atoms. Furthermore, the umklapp scatterings among phonons are reduced and the phonon mean free path is increased. Therefore, the thermal conductivity of the composite is 20%-45%higher than the bare carbon nanotubes in a temperature range of 100-500 K, but the growth rate decreases with the rise of temperature. The thermal conductivity of the composite rises with the increasing of length but in a sharper rate, and decreases with the increasing of diameter in the same rate, which is similar to the bare carbon nanotubes.

关 键 词：碳纳米管 纳米线 电缆式复合材料 导热 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TB33