碳纳米胶囊中水分子的分子动力学研究

采用分子动力学方法研究了不同温度下碳纳米胶囊中水分子及其氢键的聚集密度分布,讨论了水分子内部键角及其取向规律.计算结果表明,由于碳纳米胶囊的束缚作用,水分子主要聚集在与胶囊形状相似的三个薄层中,随着温度的升高,聚集密度峰均会展宽并向管壁移动.氢键的分布规律与水分子聚集密度类似并对其取向角分布有明显影响.与通常情况不同,在1000K高温时仍存在相当数量的氢键.在3100 K附近,碳纳米胶囊发生破裂,溢出少量水分子后自动愈合.

Molecular dynamic simulation of water molecules in carbon nanocapsule

The density distributions of water molecules and hydrogen bond in a specific nanocapsule at different temperatures were investigated by molecular dynamics simulation. We also analysed the intra-molecule angle and orientation of water molecules. The result indicates that, due to the confinement of carbon nanocapsule, water molecules are distributed mainly in three capsule-like layers, between which there are almost no water molecules. With temperature rising, the peaks of density distribution broaden to the nanotube wall. The hydrogen bonds are distributed similarly and affect the orientation of water molecules. There are a lot of hydrogen bonds at 1000 K, and the nanocapsule break with some molecules coming out at 3100 K.