Abstract Based on the molecular dynamic (MD) simulations, radial-deformation capabilities of super carbon nanotubes (SCNTs) are investigated under uniaxial tension. The investigations uncover the excellent reversible and adjustable radial-shrinkage characteristics of SCNTs, which are caused by the hierarchical assembly of carbon nanotubes (CNTs). MD simulations show that reversible-deformation ranges of SCNTs can be as much as 50%, depending on the atomistic topology in junction areas. By adopting the geometry design of the hierarchical structure, radial shrinkages of SCNTs can be adjusted in a considerable range of 10%–66%. Chirality is the major factor influencing the radial-shrinkage capability, which brings more than 30% difference. For given requirements of the diameter, shrink capability of SCNT can be enhanced by increasing the length of CNTs or choosing specific chirality. Poisson's ratios of SCNTs are found to be strain-dependent including two variation types, i.e. the monotonic decreasing type and the increase-decrease waving type. By analyzing the structural evolution of Y-junctions, the shrinkage mechanism is revealed to rely on the deformation modes of SCNTs and affected by geometric settings of the hierarchical structure. As a nanometer-scale channel structure with superior reversible and controllable characteristics, SCNTs exhibit great potentials in the applications of nano-pipelines and nano-switchers.

中文翻译：

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径向收缩率高达 66% 的超级碳纳米管的分级结构诱导可调变形

摘要 基于分子动力学（MD）模拟，研究了单轴拉伸下超级碳纳米管（SCNT）的径向变形能力。研究揭示了 SCNT 优异的可逆和可调径向收缩特性，这是由碳纳米管 (CNT) 的分层组装引起的。MD 模拟表明，SCNT 的可逆变形范围可高达 50%，具体取决于结区中的原子拓扑。通过采用分层结构的几何设计，SCNTs的径向收缩率可以在10%~66%的相当大的范围内进行调整。手性是影响径向收缩能力的主要因素，带来30%以上的差异。对于给定的直径要求，SCNT 的收缩能力可以通过增加 CNT 的长度或选择特定的手性来增强。发现SCNT的泊松比与应变相关，包括两种变化类型，即单调递减型和增减波动型。通过分析 Y 型结的结构演化，揭示了收缩机制依赖于 SCNT 的变形模式，并受层次结构几何设置的影响。SCNT作为一种具有优异可逆和可控特性的纳米级通道结构，在纳米管道和纳米开关的应用中表现出巨大的潜力。单调递减型和增减波动型。通过分析 Y 型结的结构演化，揭示了收缩机制依赖于 SCNT 的变形模式，并受层次结构几何设置的影响。SCNT作为一种具有优异可逆和可控特性的纳米级通道结构，在纳米管道和纳米开关的应用中表现出巨大的潜力。单调递减型和增减波动型。通过分析 Y 型结的结构演化，揭示了收缩机制依赖于 SCNT 的变形模式，并受层次结构几何设置的影响。SCNT作为一种具有优异可逆和可控特性的纳米级通道结构，在纳米管道和纳米开关的应用中表现出巨大的潜力。