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石墨晶体结构遭到破坏时,总是碎化为微小尺寸的片状粉末.孤立的石墨烯片在其边缘存在大量的悬挂键,使得石墨烯片的能量较高,状态也不稳定.石墨烯片卷曲形成碳纳米管后,悬挂键减少,系统能量相应降低.另一方面,石墨烯片卷曲形成碳纳米管将产生相应的形变势能,形变势能的产生将抵消由于减少石墨烯片边缘上的悬挂键所带来的能量降低,使碳纳米管的能量可能高于石墨烯片的能量,导致碳纳米管结构的不稳定.在建立碳纳米管生成的力学模型并进行深入理论分析的基础上得出了碳纳米管可以稳定存在的最小直径约为0.32nm的结论.
When the crystal structure of graphite is damaged, it always breaks down into small-sized flake powders, and the isolated graphene sheet has a large number of dangling bonds at its edges, resulting in higher energy and unstable state of the graphene sheet. After curling the carbon nanotubes, the dangling bonds decrease and the energy of the system decreases accordingly.On the other hand, the curling of the graphene sheet to produce carbon nanotubes will produce the corresponding deformation potential energy, and the generation of deformation potential energy will offset the decrease of the dangling bonds The energy of the dangling bonds is reduced so that the energy of the carbon nanotubes may be higher than that of the graphene sheets, resulting in the instability of the structure of the carbon nanotubes.Based on the in-depth theoretical analysis of the mechanical model of carbon nanotube generation The conclusion that the smallest diameter of carbon nanotubes can be stable is about 0.32nm.