Nanotubes With Well-Defined Structure: Single- and Double-Walled Imogolites
Nanotubes With Well-Defined Structure: Single- and Double-Walled Imogolites
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DOI：
10.1021/jp411086f
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发表时间：
2014-03-20
影响因子：
3.7
通讯作者：
Duarte, Helio A.
中科院分区：
文献类型：
--
作者：
Lourenco, Maicon P.;Guimaraes, Luciana;Duarte, Helio A.
本文研究了以Ge和Si为IV族元素的单壁和双壁伊莫长石纳米管的结构和电子结构。虽然这是从实验中得知的，并且在理论证实的单壁管的情况下，伊莫长石纳米管在直径上是单分散的。我们发现，由于管表面的氢键网络，伊莫戈尔石管也显示出首选的手性（之字形），并且存在一种异常稳定的管间相互作用形式，支持单分散双壁伊莫戈尔石纳米管的形成。双壁管的稳定性最强的是周长差为9个单位的管，最小的结构是锗伊莫戈柳石的（12,0）@（21,0）管和伊莫戈柳石的（9,0）@（18,0）管。这些几何因素对电子结构和力学性能的影响较小，杨氏模量为320-370 GPa，与其他黏土矿物纳米管的杨氏模量相同。
We have investigated the structure and electronic structure of single- and double-walled imogolite nanotubes with Ge and Si as group IV element. While it is known from experiment, and in the case of single-walled tubes confirmed by theory, imogolite nanotubes are monodisperse in diameter. We show that imogolite tubes are also showing a preferred chirality (zigzag), resulting from the hydrogen-bond network on the tube surfaces, and that there is an exceptionally stable form of intertube interaction that supports the formation of monodisperse double-walled imogolite nanotubes. The strongest stabilization of double-walled tubes has been found for tube indexes with nine units of difference around the circumference, and the minimum structure is found for the (12,0)@(21,0) tube in the case of germanium imogolite and (9,0)@(18,0) for imogolite. The electronic structure is only slightly affected by these geometric factors, as are the mechanical properties, which show Young moduli of 320-370 GPa, thus being in the same range as other clay mineral nanotubes.