Effect of surface structure on the sustainability of an air layer on superhydrophobic coatings in a water-ethanol mixture

Munetoshi Sakai, Tomoki Yanagisawa, Akira Nakajima, Yoshikazu Kameshima, Kiyoshi Okada

Research output: Contribution to journalArticle

61 Citations (Scopus)


Using a laser beam and its reflection, we evaluated surface air layers on two superhydrophobic coatings with different roughnesses (Ra = 1900 and 74 nm) in a water-ethanol mixture. The reflected laser intensity decreased by increasing the ethanol concentration for the superhydrophobic coating with large roughness because of increased scattering by the surface structure of the solid. However, it was almost constant and slightly increased for the coating with small roughness, probably because the liquid-air interface becomes flatter as the liquid intrudes into the surface structure. Results demonstrated that the difference in surface structure provides different sustainability of the surface air layer.

Original languageEnglish
Pages (from-to)13-16
Number of pages4
Issue number1
Publication statusPublished - Jan 6 2009
Externally publishedYes


ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy

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