论文标题
富勒烯封装在碳纳米管中的热导率降低：一项分子动力学研究
Thermal conductivity reduction in carbon nanotube by fullerene encapsulation: A molecular dynamics study
论文作者
论文摘要
其原始形式的单壁碳纳米管（SWCNT）具有较高的导热率，其进一步的改进引起了很大的兴趣。一些理论研究表明，$（10,10）$ swcnt的热导率通过c $ _ {60} $ fullerene封装大大增强。但是，最近对SWCNT束的实验表明，富勒烯封装导致减少而不是导热率的增加。在这里，我们采用三种不同的分子动力学方法来研究C $ _ {60} $封装对$（10,10）$ swcnt中热传输的影响。这三种方法一致地预测，在C $ _ {60} $封装上，$（10,10）$ swcnt的热导率降低$ 20 \％-30 \％$，与SWCNT的实验结果一致。我们证明了绿色kubo方法中有一个模拟伪像，该方法从人工对流中给出了异常大的导热率。我们的结果表明，与外部SWCNT相比，C $ _ {60} $分子很少进行热量，并通过诱导额外的声子散射来减少SWCNT的声子平均自由路径。我们还发现，$（10,10）$ swcnt的热导率单调降低，随着c $ _ {60} $分子的填充比的增加。
Single-walled carbon nanotubes (SWCNTs) in their pristine form have high thermal conductivity whose further improvement has attracted a lot of interest. Some theoretical studies have suggested that the thermal conductivity of a $(10,10)$ SWCNT is dramatically enhanced by C$_{60}$ fullerene encapsulation. However, recent experiments on SWCNT bundles show that fullerene encapsulation leads to a reduction rather than an increase in thermal conductivity. Here, we employ three different molecular dynamics methods to study the influence of C$_{60}$ encapsulation on heat transport in a $(10,10)$ SWCNT. All the three methods consistently predict a reduction of the thermal conductivity of $(10,10)$ SWCNT upon C$_{60}$ encapsulation by $20\%-30\%$, in agreement with experimental results on bundles of SWCNTs. We demonstrate that there is a simulation artifact in the Green-Kubo method which gives anomalously large thermal conductivity from artificial convection. Our results show that the C$_{60}$ molecules conduct little heat compared to the outer SWCNT and reduce the phonon mean free paths of the SWCNT by inducing extra phonon scattering. We also find that the thermal conductivity of a $(10,10)$ SWCNT monotonically decreases with increasing filling ratio of C$_{60}$ molecules.
