单壁碳纳米管与石墨基底间摩擦的模拟研究  

Simulation of Friction between Single-walled Carbon Nanotube and Graphite Substrate

作　　者：李瑞[1] 胡元中[1] 王慧[1] 

机构地区：[1]清华大学摩擦学国家重点实验室,北京100084

出　　处：《润滑与密封》2007年第11期15-17,77,共4页Lubrication Engineering

基　　金：国家自然科学基金项目(50390060);国家重点基础研究发展规划(2003CB716201)

摘　　要：采用分子动力学模拟方法研究了常温300 K时,公度、不公度情况下,单壁碳纳米管CNT(10,10)在石墨基底上的运动、摩擦行为。计算中首先使碳纳米管在基底上弛豫平衡,而后施加持续时间500 fs的固定外力,撤去外力后碳纳米管在基底上减速至相对基底静止。结果表明,碳纳米管在石墨基底上不同的放置位置决定了它与基底接触面的微观构型,从而决定了碳纳米管的运动、摩擦规律。公度时,碳纳米管先在基底上滑动,摩擦力、平动能均呈现周期性起伏,之后碳纳米管在基底上滚动、滑动、翻转,滑动、转动之间运动形式的转变提高了能量耗散,增大了摩擦力,非公度时摩擦力约为公度时的70%。非公度时碳纳米管一直在基底上滑动,平动能和摩擦力不具有周期性。　Motion and friction of single-walled carbon nanotube CNT（10,10） in commensurate and incommensurate contacts on graphite substrate at 300 K were investigated by molecular dynamics simulation.After relaxation on graphite,a uniform force is applied to set the carbon nanotube into motion,then after 500 fs the force is removed,the nanotube moves in decelerating speed until it comes to rest relative to graphite.The results show that different position of CNT（10,10） on graphite decides atomic configurations in contact region between them,and decides motion and friction of system.In commensuration,first carbon nanotube slides on graphite.Friction force and translational kinetic energy change periodicly during this period.Then carbon nanotube rotates,slides and rolls on graphite.Transition between sliding and rotation enhances energy dissipation and improves friction force.Friction in incommensurate case is about 70% of the commensurate one.For the incommensurate case,carbon nanotube slides on graphite during the whole dynamics process.Translational kinetic energy and friction force aren＇t periodic.

关 键 词：碳纳米管 公度 摩擦 分子动力学模拟 

分 类 号：TB383[一般工业技术—材料科学与工程]