热驱动碳纳米马达的转动测量数值模拟

发布时间：2018-04-10 00:26

本文选题：纳米马达　切入点：碳纳米管　出处：《西北农林科技大学》2017年硕士论文

【摘要】：多壁碳纳米管的管间具有超低摩擦特性,同时管壁具有超高模量和强度。因此,纳米管成为制造纳米器件的理想备选材料。2014年,基于双壁碳纳米管的热驱动转动纳米马达被发现以来,由于马达转子具有尺寸小、转速高的特点,造成转子的转动观测极为困难。本论文使用分子动力学方法,通过在转子转轴管上添加可变翼的方法,并结合碳管探针,考察转子转动观测与调控的可行性研究。研究取得如下成果:(1)在转子转轴上键结一段部分氢化的石墨烯纳米带,构建“碳纳米管+石墨烯”转子。当复合转子被激发转动后,石墨烯翼被带动准同步转动。当转速达到临界值时,石墨烯翼在离心力作用下克服转轴碳纳米管的范德华引力,并迅速展开。与此同时,复合转子的平均转速因转动惯量的迅速增加而陡降。观测对象尺寸变大、转速变小都可降低转动观测的难度。(2)在上述可变石墨烯翼的自由端键结一个新的碳纳米管,称为尾管,并在距离烯片完全展开后能经过的路径上布置一个碳纳米管探针。同样地,在复合转子被激发转动后,当转速达到临界值时,尾管随石墨烯翼脱离轴管的引力。此刻转速会有所下降,当转速重新回到临界值后,尾管经过探针时,会发生碰撞。通过观察探针是否出现大幅振动判断纳米马达是否转动。(3)利用上述纳米马达+探针的模型,讨论了探针位置、最大挠度与热驱动纳米马达转子转速之间的关系,建立了转速可控的纳米马达模型。模型中石墨烯翼通过两面交替氢化方式制作成纳米弹簧。数值结果表明,复合转子被激发转动中,石墨烯翼的长度会随转速的增加而增加。探针的最大挠度随尾管的速度(正比于转子平均转速)增加而增加。通过调整探针的相对位置,可以控制石墨烯翼的伸长量,从而实现转子转速的调控。
[Abstract]:The multiwalled carbon nanotubes (MCNTs) have ultra-low friction characteristics, and the wall has ultra-high modulus and strength.Therefore, nanotubes are ideal candidates for manufacturing nanodevices. Since 2014, when heat driven rotating nanometers based on double-walled carbon nanotubes were discovered, the rotor of the motor has been characterized by its small size and high speed.It is extremely difficult to observe the rotation of the rotor.In this paper, the feasibility of rotor rotation observation and control was investigated by adding variable wing to rotor shaft tube and combining carbon tube probe with molecular dynamics method.The results are as follows: 1) bonding a segment of hydrogenated graphene nanoribbons on the rotor shaft to construct a "carbon nanotube graphene" rotor.When the composite rotor is excited to rotate, the graphene wing is driven to quasi-synchronous rotation.When the rotational speed reaches the critical value, the graphene wing can overcome the van der Waals gravity of the rotating axis carbon nanotubes under centrifugal force, and expand rapidly.At the same time, the average rotational speed of the composite rotor drops sharply because of the rapid increase of the moment of inertia.A new carbon nanotube, called a tail tube, is bonded to the free end of the variable graphene wing by the larger size and smaller rotational speed of the observed object.A carbon nanotube probe is arranged on the path through which the alkene sheet is completely unfolded.Similarly, after the compound rotor is excited to rotate, when the rotational speed reaches the critical value, the tail tube is separated from the axial tube's gravity with the graphene wing.The speed will decrease at the moment, and when the speed is back to the critical value, the tail tube will collide as it passes through the probe.Using the model of the probe, the relationship between the position of the probe, the maximum deflection and the rotor speed of the thermally driven nano-motor is discussed.The model of nanometer motor with controllable speed was established.In the model, graphene wings are alternately hydrogenated on two sides to form nanoscale springs.The numerical results show that the length of graphene wing increases with the increase of rotating speed.The maximum deflection of the probe increases with the increase of the speed of the tail tube (proportional to the average rotor speed).By adjusting the relative position of the probe, the elongation of the graphene wing can be controlled and the rotor speed can be controlled.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TB383.1

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