Extreme stretching of high G:D ratio carbon nanotube fibers using super-acid
Extreme stretching of high G:D ratio carbon nanotube fibers using super-acid
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DOI：
10.1016/j.carbon.2019.07.061
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发表时间：
2019-11-01
期刊：
影响因子：
10.9
通讯作者：
Elliott, James A.
中科院分区：
文献类型：
--
作者：
Bulmer, John S.;Mizen, Jenifer E.;Elliott, James A.
少壁碳纳米管（CNT）纺织品具有无与伦比的石墨完美性和与金属手性相关的孤立、突出的径向呼吸模式（RBM），在氯磺酸（CSA）中机械拉伸到迄今为止在碳纳米管纺织品中未见的程度（原始长度的150-250%），需要的张力很小。这极大地增强了它们的微观结构取向和密度，并且在真空烘烤去除大部分残余CSA后，发现脱掺杂纤维的电导率比单晶石墨高45% -这是碳纳米管导体向石墨嵌入化合物（GICs）和传统金属发展的重要里程碑。相关表和经过验证的多元统计模型表明，电导率与拉伸程度有着压倒性的联系，尽管最终在单晶石墨水平附近饱和，这意味着存在最大的未掺杂电导率。CSA内部的拉伸程度与原始力学性能（韧性、断裂伸长率和线密度）相关；热重分析的拉曼G′：G比和上端氧化温度也预测了最佳结果。不那么原始的碳纳米管材料在CSA中拉伸到较低的程度，类似于以前的报道。本研究强调了碳纳米管纺织材料合成后处理的重要性，以获得优异的性能。(C) 2019 Elsevier Ltd.版权所有。
Few-wall carbon nanotube (CNT) textiles with unparalleled graphitic perfection and a solitary, prominent radial breathing mode (RBM) associated with metallic chirality have been mechanically stretched in chlorosulfonic acid (CSA) to a degree so far unseen in CNT textiles (150-250% of original length) with notably little tension required. This dramatically enhanced their microstructural alignment and density and, after most of the residual CSA was removed by a vacuum bake, the de-doped fiber's electrical conductivity was found to be 45% greater than single-crystal graphite - a significant milestone for CNT conductor development towards graphitic intercalation compounds (GICs) and traditional metals. Correlation tables and validated, multivariate statistical models show that conductivity is overwhelmingly linked to stretching degree, although eventually saturates near single-crystal graphite levels, implying the existence of a maximum undoped conductivity. The degree of stretching within CSA is correlated with the original mechanical properties (tenacity, elongation-to-break, and linear density); the Raman G':G ratio and the upper-end oxidation temperature in thermogravimetric analysis also predict the best results. Less graphenically pristine CNT materials stretch to a lower degree in CSA, similar to previous reports. This study highlights the importance of post-synthesis processing to achieve superior performance in carbon nanotube textile materials. (C) 2019 Elsevier Ltd. All rights reserved.