Resolving the Pinning Force of Nanobubbles with Optical Microscopy
Tan, Beng Hau
Date of Issue2017
School of Physical and Mathematical Sciences
Many of the remarkable properties of surface nanobubbles, such as unusually small contact angles and long lifetimes, are related to the force that pins them onto their substrates. This pinning force is yet to be quantified experimentally. Here, surface-attached nanobubbles are pulled with an atomic force microscope tip while their mechanical responses are observed with total internal reflection fluorescence microscopy. We estimate that a pinning force on the order of 0.1μN is required to unpin a nanobubble from its substrate. The maximum force that the tip can exert on the nanobubble is limited by the stability of the neck pulled from the bubble and is enhanced by the hydrophobicity of the tip.
Atomic force microscopy
Physical Review Letters
© 2017 American Physical Society (APS). This paper was published in Physical Review Letters and is made available as an electronic reprint (preprint) with permission of American Physical Society (APS). The published version is available at: [https://doi.org/10.1103/PhysRevLett.118.054501]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.