碳纳米管的稳定性研究

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.

Study on the stability of carbon nanotubes

When the a graphite crystal is crushed, it is breaks into micro-scale laminar flakes. There are many dangling bonds on the edge of an isolated graphite micro-sheet which elevates its energy and makes it unstable. When a graphite micro-sheet curles into a nano-tube, the number of dangling bonds decrease, and the system energy is reduced accordingly. Meanwhile, the curled sheet obtains deformation energy, which can more than counteract the energy reduction due to the diminished dangling bonds and make the CNT even less favorable energetically than the sheet, and becomes unstable. On the basis of advancing the mechanical model of the formation of CNTs, a thorough theoretical analysis was made, which lead to the conclusion that the CNTs can exist stably at a minimum diameter of approximate 0.32nm.