中国物理B ›› 2019, Vol. 28 ›› Issue (4): 44701-044701.doi: 10.1088/1674-1056/28/4/044701

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Wetting failure condition on rough surfaces

Feng-Chao Yang(杨冯超), Xiao-Peng Chen(陈效鹏)   

  1. 1 School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710129, China;
    2 School of Marine Science, Northwestern Polytechnical University, Xi'an 710072, China
  • 收稿日期:2018-11-01 修回日期:2019-01-02 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: Xiao-Peng Chen E-mail:xchen76@nwpu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11472220 and 11872315).

Wetting failure condition on rough surfaces

Feng-Chao Yang(杨冯超)1, Xiao-Peng Chen(陈效鹏)1,2   

  1. 1 School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710129, China;
    2 School of Marine Science, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2018-11-01 Revised:2019-01-02 Online:2019-04-05 Published:2019-04-05
  • Contact: Xiao-Peng Chen E-mail:xchen76@nwpu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11472220 and 11872315).

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摘要：

Wetting states and processes attract plenty of interest of scientific and industrial societies. Air entrainment, i.e., wetting failure, on smooth plate in wetting process has been investigated carefully before. Liquid bath entries of “rough” silicon wafers are studied experimentally in the present work, and the air entrainment condition is analyzed specially with the lubrication theory. The roughness effects on the moving contact lines are therefore explored. The contact line pinning is found to be the main reason for the dynamically enhanced hydrophobicity of rough surface, which implies an effective microscopic contact angle of θe=θY+90° where θY is the Young's contact angle of the material. Our results suggest that the solid surfaces can be considered as hydrophobic ones for a wide range of dynamic process, since they are normally rough. The work can also be considered as a starting point for investigating the high-speed advancing of moving contact line on rough surfaces.

关键词: wetting failure, roughness, lubrication theory, contact angle

Abstract:

Wetting states and processes attract plenty of interest of scientific and industrial societies. Air entrainment, i.e., wetting failure, on smooth plate in wetting process has been investigated carefully before. Liquid bath entries of “rough” silicon wafers are studied experimentally in the present work, and the air entrainment condition is analyzed specially with the lubrication theory. The roughness effects on the moving contact lines are therefore explored. The contact line pinning is found to be the main reason for the dynamically enhanced hydrophobicity of rough surface, which implies an effective microscopic contact angle of θe=θY+90° where θY is the Young's contact angle of the material. Our results suggest that the solid surfaces can be considered as hydrophobic ones for a wide range of dynamic process, since they are normally rough. The work can also be considered as a starting point for investigating the high-speed advancing of moving contact line on rough surfaces.

Key words: wetting failure, roughness, lubrication theory, contact angle

中图分类号:  (Thin film flows)

  • 47.15.gm
47.55.dr (Interactions with surfaces) 47.85.mf (Lubrication flows)