摘要运用分子动力学方法，分析模拟单壁碳纳米管（SWCNT）受热过程中的结构变化情况，以判断碳纳米管的热稳定性。研究目的在于考察不同势函数，升温方式，碳纳米管的长度、手性、直径等因素对其热稳定性的影响。为此，通过控制变量法，采用连续升温和非连续升温两种升温方式，以及Tersoff、AIREBO、LCBOP三种常用的势函数分别模拟了9种不同的单壁碳纳米管，以瓦解温度作为碳纳米管热稳定性强弱的评价标准。结果表明，采用Tersoff势模拟的碳纳米管的热稳定性显著强于另外两种势函数；(5,5)扶手椅型单壁碳纳米管的热稳定性强于(9,0)型单壁碳纳米管；对于上述的三种势函数，直径对单壁碳纳米管的热稳定性的影响很小；与连续升温方式相比，非连续升温方式模拟得到的碳纳米管的热稳定性更强。68049

毕业论文关键词  单壁碳纳米管  分子动力学模拟  势函数  热稳定性

毕业设计说明书（论文）外文摘要

Title      Molecular dynamics simulation of thermal stability in carbon nanotubes   

Abstract

Using molecular dynamics simulations, we simulated and analyzed the change of the structure of the single-walled carbon nanotubes (SWCNT) in the process of heating. By this means, we decided the thermal stability of carbon nanotubes, which depends on the collapsing temperature. In this essay, we studied the influence of potential function, heating mode, length, chirality and diameter of carbon nanotubes to their thermal stability. Therefore, we adopt two heating modes: persistent overheating and discontinuous heating way, with three potential functions: Tersoff type potential, AIREBO potential and LCBOP potential when simulating 9 types of single-walled carbon nanotubes. Our results show that the carbon nanotubes were more thermal stable when simulating with Tersoff type potential; Secondly, the thermal stability of (5,5) Armchair single-walled carbon nanotubes exceeds that of (9,0) zigzag; Thirdly, diameter has litter impact on the thermal stability. In addition, applying discontinuous  heating mode to simulation indicates a better thermal stability than persistent overheating.

Keywords  single-walled carbon nanotubes  molecular dynamics simulations  potential function  thermal stability

目   次

1  绪论 1

1.1  简介 1

1.2  碳纳米管的结构 2

1.3  碳纳米管的性能 4

1.4 本论文主要研究内容 5

2 分子动力学模拟方法 5

2.1  简介 5

2.2  基本原理 5

3 势函数选取 5

3.1 Tersoff势函数 6

3.2 AIREBO势函数 7

3.3 LCBOP势函数 11

4  模拟方案与方法 12

4.1  模拟方案 12

4.2 模拟方法 13

5 模拟结果与分析 15

5.1  模拟结果