Department of Mechanical Engineering, Baylor University, One Bear Place #97356, Waco, TX 76798, USA. David
Nanotechnology. 2010 May 14;21(19):195703. doi: 10.1088/0957-4484/21/19/195703. Epub 2010 Apr 21.
Single-walled carbon nanotube (SWCNT) networks have become a subject of interest due to their ability to support structural, thermal and electrical loadings, but to date their application has been hindered due, in large part, to the inability to model macroscopic responses in an industrial product with any reasonable confidence. This paper seeks to address the relationship between macroscale electrical conductivity and the nanostructure of a dense network composed of SWCNTs and presents a uniquely formulated physics-based computational model for electrical conductivity predictions. The proposed model incorporates physics-based stochastic parameters for the individual nanotubes to construct the nanostructure such as: an experimentally obtained orientation distribution function, experimentally derived length and diameter distributions, and assumed distributions of chirality and registry of individual CNTs. Case studies are presented to investigate the relationship between macroscale conductivity and nanostructured variations in the bulk stochastic length, diameter and orientation distributions. Simulation results correspond nicely with those available in the literature for case studies of conductivity versus length and conductivity versus diameter. In addition, predictions for the increasing anisotropy of the bulk conductivity as a function of the tube orientation distribution are in reasonable agreement with our experimental results. Examples are presented to demonstrate the importance of incorporating various stochastic characteristics in bulk conductivity predictions. Finally, a design consideration for industrial applications is discussed based on localized network power emission considerations and may lend insight to the design engineer to better predict network failure under high current loading applications.
单壁碳纳米管（SWCNT）网络因其能够承受结构、热和电负载而成为研究的热点，但迄今为止，由于无法以任何合理的信心在工业产品中对宏观响应进行建模，其应用受到了阻碍。本文旨在研究由 SWCNT 组成的密集网络的宏观电导率与纳米结构之间的关系，并提出了一种独特的基于物理的计算模型，用于预测电导率。所提出的模型结合了用于单个纳米管的基于物理的随机参数来构建纳米结构，例如：实验获得的取向分布函数、实验得出的长度和直径分布，以及假设的单个 CNT 手性和配位数分布。通过案例研究来研究宏观电导率与体随机长度、直径和取向分布的纳米结构变化之间的关系。模拟结果与文献中关于电导率与长度和电导率与直径的案例研究的结果非常吻合。此外，随着管取向分布函数的增加，对体电导率各向异性的预测与我们的实验结果基本一致。通过示例说明了在体电导率预测中纳入各种随机特性的重要性。最后，根据局部网络功率发射的考虑因素讨论了工业应用的设计注意事项，这可能为设计工程师提供更好地预测高电流负载下网络故障的见解。
