Superhydrophobic substrates allow the generation of giant quasi-static bubbles Articles uri icon

publication date

  • February 2021

start page

  • A25-1

end page

  • A25-14

volume

  • 912

International Standard Serial Number (ISSN)

  • 0022-1120

Electronic International Standard Serial Number (EISSN)

  • 1469-7645

abstract

  • We report on experiments of the quasi-static growth and detachment of air bubbles in
    water from a superhydrophobic substrate, overcoming the maximum size limitation of
    conventional injectors due to the Rayleigh–Taylor instability. The observations are in good
    agreement with a hydrostatic model, demonstrating that bubbles grow through a sequence
    of quasi-equilibrium states. Our experiments corroborate the theoretical prediction of a
    maximum bubble volume of approximately 6.04π and a critical base radius of 3.22, both
    numbers in units of the capillary length (Michael &# Williams, Proc. R. Soc. Lond. A.
    vol. 351, 1976, pp. 117&;8211#127). This maximum is also reached when bubbles grow in an
    unbounded, ideally non-wetting surface, establishing the ultimate size limit of quasi-static
    bubble formation.

keywords

  • bubble dynamics; contact lines; coating