Significance of Bundling Effects on Carbon Nanotubes' Response to Hydrostatic Compression
Significance of Bundling Effects on Carbon Nanotubes' Response to Hydrostatic Compression
复制标题
成束效应对碳纳米管静水压缩响应的意义
DOI：
10.1021/acs.jpcc.5b09082
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Sun Y
中科院分区：
文献类型：
--
作者：
Sun Y
碳纳米管的G模压力系数反映了刚性sp2键的压力依赖性，其研究对于理解其非凡的力学性质以及基本力学是必不可少的。然而，这是阻碍了碳纳米管样品的可用性，只有作为束或孤立的表面活性剂。十八胺功能化的碳纳米管大部分是单径的，并且可以在没有表面活性剂的情况下稳定地分散在1，2-二氯乙烷和氯仿中。在这里，我们进行高压拉曼光谱对这些管，并获得其实验G模式的压力系数为个别管和束。在1，2-二氯乙烷中，管束的G+压力系数仅为单个管的一半，在氯仿中约为三分之二。在1，2-二氯乙烷中，束的G-压力系数约为G+的三分之一，在氯仿中也大致相同。这些结果第一次提供了明确的实验证据，证明了集束对碳纳米管G模式压力系数的显著影响，并将其确定为文献中缺乏共识的主要原因之一。
The study of the G-mode pressure coefficients of carbon nanotubes, reflecting the stiff sp2bond pressure dependence, is essential to the understanding of their extraordinary mechanical properties as well as fundamental mechanics. However, it is hindered by the availability of carbon nanotubes samples only as bundles or isolated with surfactants. Octadecylamine-functionalized carbon nanotubes are mostly of a single diameter and can be stably dispersed in 1,2-dichloroethane and chloroform without surfactants. Here we perform high-pressure Raman spectroscopy on these tubes and obtain their experimental G-mode pressure coefficients for individual tubes and bundles. The G+pressure coefficient for bundles is only about half of that for individual tubes in 1,2-dichloroethane and is about two-thirds in chloroform. The G–pressure coefficient for bundles is about one-third of G+in 1,2-dichloroethane and about the same in chloroform. These results for the first time provide unambiguous experimental evidence of the significant effect of bundling on carbon nanotubes’ G-mode pressure coefficients, identifying it as one of the major reasons for the lack of consensus on what the values should be in the literature.