Si表面间水平碳纳米管束的分子动力学模拟研究

本文采用分子动力学模拟方法研究了Si表面间单壁水平碳纳米管束SWCNT (10,10)的变形和摩擦特性.系统在弛豫平衡后,首先对碳纳米管束施加压力至碳纳米管或Si表面结构破坏.之后在无压力和高压力两种情况下使上表面沿水平方向做剪切运动以研究碳纳米管束的摩擦特性.结果表明,由于碳纳米管的柔韧性,碳纳米管束在加载过程中出现明显变形,但直至3.8 GPa高压下并无结构破坏.系统无压力时SWCNT (10,10)在原地轻微随机滚动,压力为3.8 GPa时,碳纳米管束出现了整体的轻微滑动,同时伴随无规律的轻微滚动, 关键词： 碳纳米管束 摩擦 分子动力学模拟

Molecular dynamics simulation on carbon nanotube bundles sandwitched between Si surfaces

Distortion and friction of bundle of SWCNT(10,10) sandwiched between two hydrogen-terminated Si(1,1,0) surfaces are investigated by molecular dynamics simulation. After reaching the equilibrium state, a compressive force is applied to the carbon nanotubes until structural destruction appears on carbon nanotubes or substrates. Friction of the system is then investigated when the upper substrate slides along X direction under no load and high load conditions. Distortion of carbon nanotubes can be observed during loading process and no structural destruction occurs even under the pressure as high as 3.8GPa because of their flexibility. Bundles of SWCNT (10,10) roll randomly and slightly under no pressure condition, but exhibit slide-and-roll combined motion under 3.8GPa pressure. The results also show relatively low lateral forces in both cases. The low friction is attributed to the relatively weak Lennard-Jones interaction between substrate and carbon nanotubes with no hanging bond. Excellent performance is therefore expected when carbon nanotubes without defects are used as lubricant or addictives.