中国物理B ›› 2019, Vol. 28 ›› Issue (1): 16801-016801.doi: 10.1088/1674-1056/28/1/016801

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Approximate expression of Young's equation and molecular dynamics simulation for its applicability

Shu-Wen Cui(崔树稳), Jiu-An Wei(魏久安), Wei-Wei Liu(刘伟伟), Ru-Zeng Zhu(朱如曾), Qian Ping(钱萍)   

  1. 1 Department of Physics and Information Engineering, Cangzhou Normal University, Cangzhou 061001, China;
    2 State Key Laboratory of Nonlinear Mechanics(LNM) and Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Science, Beijing 100190, China;
    3 Silfex, a Division of Lam Research, 950 South Franklin Street, Eaton, Ohio, 45320, USA;
    4 Department of Physics, University of Science and Technology Beijing, Beijing 100083, China
  • 收稿日期:2018-06-15 修回日期:2018-10-31 出版日期:2019-01-05 发布日期:2019-01-05
  • 通讯作者: Ru-Zeng Zhu E-mail:zhurz@lnm.imech.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11072242), the Key Scientific Studies Program of Hebei Province Higher Education Institute, China (Grant No. ZD2018301), and Cangzhou National Science Foundation, China (Grant No. 177000001).

Approximate expression of Young's equation and molecular dynamics simulation for its applicability

Shu-Wen Cui(崔树稳)1,2, Jiu-An Wei(魏久安)2,3, Wei-Wei Liu(刘伟伟)1, Ru-Zeng Zhu(朱如曾)2, Qian Ping(钱萍)4   

  1. 1 Department of Physics and Information Engineering, Cangzhou Normal University, Cangzhou 061001, China;
    2 State Key Laboratory of Nonlinear Mechanics(LNM) and Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Science, Beijing 100190, China;
    3 Silfex, a Division of Lam Research, 950 South Franklin Street, Eaton, Ohio, 45320, USA;
    4 Department of Physics, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2018-06-15 Revised:2018-10-31 Online:2019-01-05 Published:2019-01-05
  • Contact: Ru-Zeng Zhu E-mail:zhurz@lnm.imech.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11072242), the Key Scientific Studies Program of Hebei Province Higher Education Institute, China (Grant No. ZD2018301), and Cangzhou National Science Foundation, China (Grant No. 177000001).

摘要:

In 1805, Thomas Young was the first to propose an equation (Young's equation) to predict the value of the equilibrium contact angle of a liquid on a solid. On the basis of our predecessors, we further clarify that the contact angle in Young's equation refers to the super-nano contact angle. Whether the equation is applicable to nanoscale systems remains an open question. Zhu et al.[College Phys. 4 7 (1985)] obtained the most simple and convenient approximate formula, known as the Zhu-Qian approximate formula of Young's equation. Here, using molecular dynamics simulation, we test its applicability for nanodrops. Molecular dynamics simulations are performed on argon liquid cylinders placed on a solid surface under a temperature of 90 K, using Lennard-Jones potentials for the interaction between liquid molecules and between a liquid molecule and a solid molecule with the variable coefficient of strength a. Eight values of a between 0.650 and 0.825 are used. By comparison of the super-nano contact angles obtained from molecular dynamics simulation and the Zhu-Qian approximate formula of Young's equation, we find that it is qualitatively applicable for nanoscale systems.

关键词: molecular dynamics simulation, Young's equation, surface tension, Zhu-Qian approximate formula of Young', s equation

Abstract:

In 1805, Thomas Young was the first to propose an equation (Young's equation) to predict the value of the equilibrium contact angle of a liquid on a solid. On the basis of our predecessors, we further clarify that the contact angle in Young's equation refers to the super-nano contact angle. Whether the equation is applicable to nanoscale systems remains an open question. Zhu et al.[College Phys. 4 7 (1985)] obtained the most simple and convenient approximate formula, known as the Zhu-Qian approximate formula of Young's equation. Here, using molecular dynamics simulation, we test its applicability for nanodrops. Molecular dynamics simulations are performed on argon liquid cylinders placed on a solid surface under a temperature of 90 K, using Lennard-Jones potentials for the interaction between liquid molecules and between a liquid molecule and a solid molecule with the variable coefficient of strength a. Eight values of a between 0.650 and 0.825 are used. By comparison of the super-nano contact angles obtained from molecular dynamics simulation and the Zhu-Qian approximate formula of Young's equation, we find that it is qualitatively applicable for nanoscale systems.

Key words: molecular dynamics simulation, Young's equation, surface tension, Zhu-Qian approximate formula of Young', s equation

中图分类号:  (Wetting)

  • 68.08.Bc
68.03.Cd (Surface tension and related phenomena) 61.46.Fg (Nanotubes) 87.10.Tf (Molecular dynamics simulation)