Knudsen gas provides nanobubble stability.
We provide a model for the remarkable stability of surface nanobubbles to bulk dissolution. The key to the solution is that the gas in a nanobubble is of Knudsen type. This leads to the generation of a bulk liquid flow which effectively forces the diffusive gas to remain local. Our model predicts the presence of a vertical water jet immediately above a nanobubble, with an estimated speed of ∼3.3  m/s, in good agreement with our experimental atomic force microscopy measurement of ∼2.7  m/s. In addition, our model also predicts an upper bound for the size of nanobubbles, which is consistent with the available experimental data.
Physics of Fluids, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. j.r.t.seddon@utwente.nl
James R T
JR
Seddon
Harold J W
HJ
Zandvliet
Detlef
D
Lohse
D005740:Gases / Q000737:chemistry*; D021621:Imaging, Three-Dimensional; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*
D005740:Gases