Nanobubbles give evidence of incomplete wetting at a hydrophobic interface

Force measurements with the atomic force microscope: Technique, interpretation and applications

“…Being able to image nanobubbles confirms that they can be stable on hydrophobic surfaces on the time scale of an AFM experiment. It is, however, not clear whether they form spontaneously under normal conditions or only if the dissolved gas is supersaturated [545], the samples were in contact with air before being immersed in water [542], or the AFM tip itself induced bubble formation [546].…”

“…By scanning a small region with increased tapping amplitude, the nanobubbles in this region fused to one bigger bubble. The figure was kindly provided by Klösgen [546].…”

Effect of impurities in description of surface nanobubbles

“…Effects like negative line tension [21] or pseudo partial wetting [6] have been argued to be responsible for the unexpectedly small (gas-side) contact angle. On the other hand, the issue of superstability has been addressed by postulating a compensating gas influx into the bubble at the contact line [20], thanks to the attraction of gas molecules towards the hydrophobic walls [22].…”

Superstability of Surface Nanobubbles

“…In recent years, numerous experiments revealed the existence of nanoscopic soft domains at the liquid-solid interface, see [1,2,3,4,5,6,7,8,9,10] and references therein. Most experiments employ atomic force microscopy (AFM) [1,2,3,4,5,6,7,8], but other techniques [9,10] have been used as well.…”

“…Most experiments employ atomic force microscopy (AFM) [1,2,3,4,5,6,7,8], but other techniques [9,10] have been used as well. The most consistent interpretation of these experiments is that the soft domains, which resemble spherical caps with heights of the order of 10 nm and diameters of the order of 100 nm, are so-called surface nanobubbles, i.e., nanoscale gas bubbles located at the liquid-solid interface.…”