物理化学学报 >> 2008, Vol. 24 >> Issue (11): 2047-2052.doi: 10.3866/PKU.WHXB20081119

研究论文 上一篇    下一篇

金纳米颗粒周围水的结构和动力学性质的分子动力学模拟

杨振; 杨晓宁; 徐志军   

  1. 南京工业大学化学化工学院, 材料化学工程国家重点实验室, 南京 210009
  • 收稿日期:2008-06-24 修回日期:2008-07-29 发布日期:2008-11-10
  • 通讯作者: 杨晓宁 E-mail:yangxia@njut.edu.cn

Molecular Dynamics Simulation of Structure and Dynamics Properties of Water Near an Au Nanoparticle

YANG Zhen; YANG Xiao-Ning; XU Zhi-Jun   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China
  • Received:2008-06-24 Revised:2008-07-29 Published:2008-11-10
  • Contact: YANG Xiao-Ning E-mail:yangxia@njut.edu.cn

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摘要： 采用经典的分子动力学模拟方法系统地研究了在常温条件下金纳米颗粒周围水的结构与动力学性质. 结果表明, 水分子在纳米颗粒附近形成了明显的多层结构. 同时随着径向距离的减小, 水分子的空间取向也从无序排列趋向于有序排列. 通过分析界面处不同水层中的均方位移及停留时间分布, 发现紧贴颗粒表面的第一和第二水层中的水分子表现出很低的扩散系数, 而第三和第四水层中的水分子则能够轻易地离开界面区域而进入主体相区域. 此外, 在界面处的每个水分子的氢键平均数要高于在主体相的平均值.

关键词: 纳米颗粒, 水, 分子动力学, 结构, 扩散, 氢键

Abstract: Classical molecular dynamics simulations were employed to investigate the structural and dynamical properties of water near an Au nanoparticle at roomtemperature. The simulation results showed that a well-defined multi-layered structure of water was formed close to the surface of the Au nanoparticle and the orientation of water molecules in the interfacial region changed gradually fromthe random arrangement to the ordered arrangement with the reduction in the radial distance. By analyzing the mean square displacement and occupation time distribution in different water layers, we found that water molecules in the first and second layers display very low diffusivity, whereas water molecules in the third and fourth layers could migrate fromthe interfacial region to the bulk region at short time. Additionally, the average number of hydrogen bonds per water molecule in the interfacial region was higher than that in the bulk phase.

Key words: Nanoparticle, Water, Molecular dynamics, Structure, Diffusion, Hydrogen bond