Processing and properties of highly enriched double-wall carbon nanotubes
Processing and properties of highly enriched double-wall carbon nanotubes
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DOI：
10.1038/nnano.2008.364
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发表时间：
2009-01-01
影响因子：
38.3
通讯作者：
Hersam, Mark C.
中科院分区：
文献类型：
--
作者：
Green, Alexander A.;Hersam, Mark C.
碳纳米管由一个或多个同心的石墨烯圆柱体组成，并且正在研究利用其优异的热，机械，电子和光学特性的各种应用。双壁纳米管是研究壁间相互作用对双壁或多壁纳米管性能影响的理想体系。然而，目前合成双壁纳米管的技术产生不需要的单壁和多壁纳米管。在这里，我们展示了如何使用密度梯度超速离心法通过浮力密度的差异将双壁纳米管从单壁和多壁纳米管的混合物中分离出来。该技术导致样品高度富集具有相似外壁直径的单壁或双壁纳米管，双壁纳米管平均比单壁纳米管长44%。当双壁纳米管用于透明导体时，其较长的平均长度提供了明显的优势。
Carbon nanotubes consist of one or more concentric graphene cylinders and are under investigation for a variety of applications that make use of their excellent thermal, mechanical, electronic and optical properties. Double-wall nanotubes are ideal systems for studying the interwall interactions influencing the properties of nanotubes with two or more walls. However, current techniques to synthesize double-wall nanotubes produce unwanted single- and multiwall nanotubes. Here, we show how density gradient ultracentrifugation can be used to separate double-wall nanotubes from mixtures of single- and multiwall nanotubes through differences in their buoyant density. This technique results in samples that are highly enriched in either single- or double-wall nanotubes of similar outer wall diameter, with the double-wall nanotubes being, on average, similar to 44% longer than the single-wall nanotubes. The longer average length of the double-wall nanotubes provides distinct advantages when they are used in transparent conductors.