High thermal conductivities of carbon nanotube films and micro-fibres and their dependence on morphology
High thermal conductivities of carbon nanotube films and micro-fibres and their dependence on morphology
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DOI：
10.1016/j.carbon.2016.12.006
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发表时间：
2017-04-01
期刊：
影响因子：
10.9
通讯作者：
Windle, Alan H.
中科院分区：
文献类型：
--
作者：
Gspann, Thurid S.;Juckes, Stefan M.;Windle, Alan H.
采用平行热导法测量了浮动催化化学气相沉积法制备的碳纳米管薄膜和微纤维的热导率。碳纳米管薄膜的面内热导率为110 W m（-1）k（-1）。在线冷凝成微纤维形态，横向平面的二维减少，包括溶剂蒸发过程中的一些轴向拉伸，导致室温热导率值高达770 +/-10 W m（-1）k（-1），这是迄今为止报道的CNT块体材料的最高热导率。具体而言，这与热处理碳纤维的最大热导率相匹配，但Umklapp散射过程的起始温度更高（300 K而不是150 K）。我们选择了四种样品类型来研究取向、纯度和单壁或多壁特性对其热导率的影响。对于纺丝材料的导电性和导热性，即没有任何合成后处理，我们表明CNT束排列的密度和质量仍然是影响这些性能的主要因素，超过了单壁或多壁纳米管特性的影响。这提出了这样的承诺，即通过最佳的对准和接合点，宏观CNT纤维可以实现更高的热导率值。(C)2016由Elsevier Ltd.出版
Thermal conductivity of carbon nanotube (CNT) films and micro-fibres synthesised by floating catalyst chemical vapour deposition was measured by the parallel thermal conductance method. CNT films showed in-plane thermal conductivities of 110 W m(-1) k(-1). Online condensation into a micro-fibre morphology a two-dimensional reduction in the transverse plane, including some axial stretching during solvent evaporation resulted in room-temperature thermal conductivity values as high as 770 +/- 10 W m(-1) k(-1), which is the highest thermal conductivity reported for CNT bulk materials to date. In specific terms, this matches the maximum thermal conductivity of heat-treated carbon fibre, but with a higher onset temperature for Umklapp scattering processes (300 K rather than 150 K). We selected four sample types to investigate effects of alignment, purity, and single- or multi-wall character on their thermal conductivity. For both the electrical and thermal conductivity of as-spun material, i.e. without any post-synthesis treatment, we show that the density and quality of CNT bundle alignment are still the predominant factors affecting these properties, outweighing the influence of single- or multi-walled character of the nanotubes. This raises the promise that, with optimal alignment and junction points, even higher values of thermal conductivity are achievable for macroscopic CNT fibres. (C) 2016 Published by Elsevier Ltd.