碳纳米管网络结构导热特性的分子动力学模拟研究

发布时间：2018-05-17 01:08

本文选题：碳纳米管 + 分子动力学模拟　；参考：《华北电力大学》2017年硕士论文

【摘要】：碳纳米管及其分子结是构成碳纳米电子器件和碳纳米管网络结构的基本组成单元。近年来碳纳米管在纳米电子器件及碳纳米管网络的宏观体新型材料的研究方面得到了广泛的关注。单个碳纳米管具有超强的导热特性,研究碳纳米管分子结及其网络的导热特性对于碳纳米管在强化传热领域的应用具有十分重要的意义。本文主要针对碳纳米管随机网络的导热性能进行了研究,模拟研究了单壁、双壁以及三壁碳纳米管的管间热导和轴向热阻,并提出了一种双壁和多壁碳纳米管随机网络热导率预测的新模型。主要包含以下内容:(1)运用分子动力学模拟计算了交叉单热接触点的单壁碳纳米管的管间热导,并讨论了管间距离对管间热导的影响;计算了双热接触点、三热接触点不同情况下的管间接触热导,为碳纳米管随机网络整体的热导率的计算提供了先决条件。(2)运用分子动力学模拟了烧结形成双壁以及三壁碳纳米管分子结的过程,模拟计算了双壁以及三壁碳纳米管分子结的管间热导和轴向热阻,为分子结连接的碳纳米管网络结构的热导率预测提供了必要的参数。(3)对Chalopin模型和Volkov模型进行对比分析,并提出了一种双壁和多壁碳纳米管随机网络的热导率预测的新模型,计算比较了不同密度下的单壁、双壁以及多壁碳纳米管网络的热导率,利用计算结果解释了通过烧结能提高双壁以及多壁碳纳米管网络热导率的机理。
[Abstract]:Carbon nanotubes and their molecular junctions are the basic components of carbon nanoelectronic devices and carbon nanotubes network structure. In recent years, carbon nanotubes (CNTs) have received extensive attention in the field of nanoelectronic devices and new macrostructure materials of CNTs networks. Single carbon nanotubes (CNTs) have super thermal conductivity. It is very important to study the thermal conductivity of CNTs molecular junctions and their networks for the application of CNTs in the field of heat transfer enhancement. In this paper, the thermal conductivity and axial thermal resistance of single, double and three-walled CNTs are studied. A new model for predicting the thermal conductivity of double-walled and multi-walled carbon nanotube networks is proposed. The main contents are as follows: (1) the intertube thermal conductivity of single-walled carbon nanotubes with cross single thermal contact point is calculated by molecular dynamics simulation, and the influence of the distance between tubes on the thermal conductivity between tubes is discussed, and the double thermal contact point is calculated. The contact thermal conductivity between tubes at different thermal contact points provides a precondition for the calculation of the overall thermal conductivity of carbon nanotubes (CNTs). The molecular dynamics simulation is used to simulate the formation of double-walled and three-walled CNTs molecular junctions. The thermal conductivity and axial thermal resistance of double-walled and three-walled CNTs molecular junctions are simulated and calculated, which provides the necessary parameters for predicting the thermal conductivity of CNTs connected by molecular junctions. The Chalopin model and the Volkov model are compared and analyzed. A new model for predicting the thermal conductivity of double-walled and multi-walled CNT networks is proposed. The thermal conductivity of single-walled, double-walled and multi-walled CNT networks with different densities is calculated and compared. The mechanism of increasing the thermal conductivity of double-walled and multi-walled CNT networks by sintering is explained by using the calculated results.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TB383.1

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