THEORETICAL CALCULATIONS OF THERMOPHYSICAL PROPERTIES OF SINGLEWALL CARBON NANOTUBE BUNDLES
Carbon nanotube bundles are the promising thermal interfacial materials due to their excellent mechanical and thermal characteristics. In this paper, the phonon dispersion relations (PDR) and the density of states (DOS) of the single-wall carbon nanotube (SWCNT) bundles are calculated using the force constant model, and the calculation results show that the inter-tube interaction leads to significant frequency raise of the low frequency modes. To verify the applied calculation method, the specific heat of a single SWCNT is calculated firstly based on the obtained PDR and the results coincide well with the experimental data. Moreover, the specific heat of the bundles is calculated and exhibits a slight reduction at low temperatures compared to that of the single SWCNT. The thermal conductivity of the bundles at low temperatures is calculated by using the ballistic transport model. The calculation results indicate that the inter-tube interaction, i.e. van der Waals interaction, hinders heat transfer and cannot be neglected at extremely low temperatures. For (5, 5) bundles, the relative difference of the thermal conductivity caused by ignoring inter-tube effect rises rapidly at extremely low temperatures, reaches the maximum value 26％ around 17K, and then decreases slowly and tends to stable value, which means the significant inter-tube interactions effect on the thermal conductivity (TC).
Tingting Miao Mengxuan Song Weigang Ma Xing Zhang
Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing, China, 100084
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
695-700
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）