Characterization of Thermal Transport in Carbon Nanotube Yarns
Characterization of Thermal Transport in Carbon Nanotube Yarns
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DOI：
10.1260/1759-3093.5.2.59
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
Jianli Wang;Si-Ru He;Jia-Wei Bao;Xing Zhang;Juekuan Yang;Yunfei Chen
中科院分区：
文献类型：
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作者：
Jianli Wang;Si-Ru He;Jia-Wei Bao;Xing Zhang;Juekuan Yang;Yunfei Chen
碳纳米管纱线（CNTY）在化学气相沉积反应器中直接从气凝胶形式纺成。初生CNTY经过不同的后处理，如硝酸处理、加捻和碘掺杂。缺陷浓度由拉曼光谱检测，有效热导率由T型探针测量。结果表明，随着酸处理和碘掺杂引起的缺陷的增加，单位长度的晶格热导率平稳下降。加捻纱线引入中等缺陷，但随着扭转角增加到~70°，观察到单位长度的晶格热导率异常下降，表明CNT受到扭转应力时出现声子软化现象。有效导热系数随孔隙率的降低而线性增加，然而，对于高度致密的CNTY，这种线性关系是否成立仍然是一个悬而未决的问题。
The carbon nanotube yarns (CNTYs) are directly spun from an aerogel form in a chemical vapor deposition reactor. The as-spun CNTYs are subjected to different post-processes, such as nitric acid treatment, twisting, and doping with iodine. The defect concentrations are detected by Raman spectroscopy, and the effective thermal conductivity is measured by a T-type probe. The results show that, the lattice thermal conductance per unit length decreases smoothly with increasing defects induced by acid treatment and iodine-doping. The twisted yarn introduces moderate defect, but an abnormal decrease in the lattice thermal conductance per unit length is observed as the twist angle increases to ~70°, indicating the phonon-soften phenomenon when CNT is subjected to the torsion stress. The effective thermal conductivity is found to increase linearly as porosity decreases, however, it is still an open question if the linear relationship holds true for highly densified CNTYs.