Controlled effect of ultrasonic cavitation on hydrophobic/ hydrophilic surfaces

Valentina Belova, Dmitry A. Gorin, Dmitry G. Shchukin, Helmuth Möhwald

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Controlling cavitation at the solid surface is of increasing interest, as it plays a major role in many physical and chemical processes related to the modification of solid surfaces and formation of multicomponent nanoparticles.Here, we show a selective control of ultrasonic cavitation on metal surfaces with different hydrophobicity. By applying a microcontact printing technique we successfully formed hydrophobic/hydrophilic alternating well-defined microstructures on aluminium surfaces. Fabrication of patterned surfaces provides the unique opportunity to verify a model of heterogeneous nucleation of cavitation bubbles near the solid/water interface by varying the wettability of the surface, temperature and ultrasonic power. At the initial stage of sonication (up to 30 min), microjets and shock waves resulting from the collapsing bubbles preferably impact the hydrophobic surface, whereas the hydrophilic areas of the patterned Al remain unchanged. Longer sonication periods affect both surfaces. These findings confirm the expectation that higher contact angle causes a lower energy barrier, thus cavitation dominates at the hydrophobic surfaces. Experimental results are in good agreement with expectations from nucleation theory. This paper illustrates a new approach to ultrasound induced modification of solid surfaces resulting in the formation of foam-structured metal surfaces.

Original languageEnglish
Pages (from-to)417-425
Number of pages9
JournalACS Applied Materials and Interfaces
Volume3
Issue number2
DOIs
Publication statusPublished - 23 Feb 2011
Externally publishedYes

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Keywords

  • Aluminium
  • Cavitation
  • Heterogeneous nucleation
  • Hydrophobic and hydrophilic surface
  • Nucleation energy
  • Nucleation rate
  • Ultrasound

ASJC Scopus subject areas

  • Materials Science(all)

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