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采用分子动力学模拟方法研究单壁碳纳米管在石墨基底上的运动.首先碳纳米管在基底弛豫至平衡状态,然后对其施加一固定外力,撤去外力后,碳纳米管在基底上逐渐减速至停止.为了研究管径、手性角对运动方式的影响,本文选择了C(10,10),C(10,9),C(10,8),C(10,5),C(10,0),C(8,8)六种单壁碳纳米管进行模拟.结果表明,碳纳米管在石墨基底上的运动方式由手性角决定,与管径无关.手性角等于30°时,碳纳米管与石墨基底之间为公度结构,碳纳米管的运动出现周期性的滑动和翻滚现象;手性角大于28.3°小于30°时,碳纳米管一边向前滑动一边滚动;手性角小于26.3°时,碳纳米管在基底上滑动.碳纳米管的手性角决定了它与石墨基底接触界面的微观构型,从而决定了碳纳米管的运动方式.Motion of single-walled carbon nanotubes on graphite substrate is investigated by using molecular dynamics simulation in this paper. Following a relaxation to the equilibrium state, a uniform force is applied to carbon nanotubes for a period of time to set them into motion. After the applied force being removed, carbon nanotubes move relative to the substrate in decelerating speed until they come to a full rest in the end. Different tube radius and chiral angles are selected during simulation. The results show that motion of carbon nanotubes is mainly affected by the chiral angle but independent of tube radius. When the chiral angle is 30°, periodic transition between sliding and rolling is observed due to the periodic change of atomic configuration during the motion. When chiral angle is between 28.3° and 30°, sliding and rotating take place at the same time. When chiral angle is less than 26.3°, only sliding is observed. Different chiral angles result in different atomic configurations in the contact region between carbon nanotubes and graphite substrate, which gives rise to different styles of motion.
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Keywords:
- molecular dynamics simulations /
- carbon nanotubes /
- kinetic energy /
- commensuration







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