Separation of Specific Single-Enantiomer Single-Wall Carbon Nanotubes in the Large-Diameter Regime
Separation of Specific Single-Enantiomer Single-Wall Carbon Nanotubes in the Large-Diameter Regime
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DOI：
10.1021/acsnano.9b08244
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发表时间：
2020-01-01
期刊：
影响因子：
17.1
通讯作者：
Flavel, Benjamin S.
中科院分区：
文献类型：
--
作者：
Li, Han;Gordeev, Georgy;Flavel, Benjamin S.
采用两级水两相萃取（ATPE）技术对直径大于1.1 nm的单壁碳纳米管（SWCNTs）进行了高浓度、高纯度的对映体分离。总共分离出五种不同的直径为1.41 nm的纳米管，包括金属和半导体。我们通过吸收光谱、圆二色光谱、共振拉曼光谱和光致发光映射来表征这些群体，揭示并证实了模式依赖的光学依赖性。利用表面活性剂对控制ATPE分离中分配的SWCNTs的竞争性吸附的知识，我们描述了一种先进的酸添加方法，可以对这些选择的纳米管的分离进行精细控制。此外，我们发现，对于确保起始材料的均匀性并进一步提高分离收率，内腔填充是一个之前未被认识到但却很重要的因素，其中填充烷烃的SWCNTs效果最好，其次是空SWCNTs，而填充水的SWCNTs固有的不均匀性导致其分离效果更差。最后，我们展示了这些纳米管在场效应晶体管中的潜在用途。
The enantiomer-level isolation of single-walled carbon nanotubes (SWCNTs) in high concentration and with high purity for nanotubes greater than 1.1 nm in diameter is demonstrated using a two-stage aqueous two-phase extraction (ATPE) technique. In total, five different nanotube species of similar to 1.41 nm diameter are isolated, including both metallics and semiconductors. We characterize these populations by absorbance spectroscopy, circular dichroism spectroscopy, resonance Raman spectroscopy, and photoluminescence mapping, revealing and substantiating mod-dependent optical dependencies. Using knowledge of the competitive adsorption of surfactants to the SWCNTs that controls partitioning within the ATPE separation, we describe an advanced acid addition methodology that enables the fine control of the separation of these select nanotubes. Furthermore, we show that endohedral filling is a previously unrecognized but important factor to ensure a homogeneous starting material and further enhance the separation yield, with the best results for alkane-filled SWCNTs, followed by empty SWCNTs, with the intrinsic inhomogeneity of water-filled SWCNTs causing them to be worse for separations. Lastly, we demonstrate the potential use of these nanotubes in field-effect transistors.