Direct Observation of Gas Meniscus Formation on a Superhydrophobic Surface

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Mimmi Eriksson
  • Mikko Tuominen
  • Mikael Järn
  • Per Martin Claesson
  • Viveca Wallqvist
  • Hans Jürgen Butt
  • Doris Vollmer
  • Michael Kappl
  • Joachim Schoelkopf
  • Patrick Gane

  • Hannu Teisala
  • Agne Swerin

Research units

  • KTH Royal Institute of Technology
  • Max Planck Institute for Polymer Research
  • Omya AG
  • RISE Research Institutes of Sweden
  • Research Institutes of Sweden AB (RISE)

Abstract

The formation of a bridging gas meniscus via cavitation or nanobubbles is considered the most likely origin of the submicrometer long-range attractive forces measured between hydrophobic surfaces in aqueous solution. However, the dynamics of the formation and evolution of the gas meniscus is still under debate, in particular, in the presence of a thin air layer on a superhydrophobic surface. On superhydrophobic surfaces the range can even exceed 10 μm. Here, we report microscopic images of the formation and growth of a gas meniscus during force measurements between a superhydrophobic surface and a hydrophobic microsphere immersed in water. This is achieved by combining laser scanning confocal microscopy and colloidal probe atomic force microscopy. The configuration allows determination of the volume and shape of the meniscus, together with direct calculation of the Young-Laplace capillary pressure. The long-range attractive interactions acting on separation are due to meniscus formation and volume growth as air is transported from the surface layer.

Details

Original languageEnglish
Pages (from-to)2246-2252
Number of pages7
JournalACS Nano
Volume13
Issue number2
Publication statusPublished - 26 Feb 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • AFM colloidal probe, capillary forces, laser scanning confocal microscopy, superhydrophobicity, wetting, HYDROPHOBIC SURFACES, SOLID-SURFACES, ATTRACTION, FORCES, WATER, DROP

ID: 32646284