Surface Nanobubbles

In this review we up to now dealt with surface micro- and nanobubbles in artificially produced surface pits. These bubbles served as cavitation nuclei. One wonders whether also naturally 

---

Borkent BM, Dammer SM, Schonherr H, Vancso GJ, Lohse D (2007) Superstability of surface nanobubbles. Phys Rev Lett 98 204502... 

Tarabkova, H., Janda, P. Nanobubble assisted nanopatteming utilized for ex situ identification of surface nanobubbles. J. Phys. Condensed Matter. 25(18), 184001 (2013)... 

Brenner, M., Lohse, D. Dynamic equilibrium mechanism for surface nanobubble stabilization. Phys. Rev. Lett. 101, 214505 (2008)... 

Mazumder, M., Bhushan, B. Propensity and geometrical distribution of surface nanobubbles effect of electrolyte, roughness, ph, and substrate bias. Soft Matter 7,9184 (2011)... 

Tensile stress imposed by shrinking nanobubble perimeter is expected to squeeze and push up the surface delimited by surface nanobubble foot radius (Fig. 12.12) hence the nanoprotmsions are formed. Nanomorphology, elastic properties, and thickness of the hydrophobic film are among properties influencing pattern, which may appear in a form of nanopinholes or nanoprotmsions [16]. 

A modification of this scenario would be a nanobubble-coated surface, that is, a heterogeneous two-phase depletion layer. " However, as it has been discussed yet in, nanobubbles will reduce the viscosity of the surface layer only if surface tension is small enough (which means that the bubbles deform). If the shape of the nanobubbles will remain a spherical lens, rjg should exceed the bulk viscosity. There remains still an open question connected with the exact expression for the effective viscosity of the layer of surface nanobubbles. 

Figure 7.12 Surface nanobubble formation on a silanated Si surface with increasing temperature (figure taken from. )...

Figure 7.13 Preferred surface nanobubble radius ofthe nanobubbles of Fig. 7.12. The error bar represents one standard deviation.

As surface nanobubbles have sizes similar to the nanopits used in the previous experiment, Borkent et alf asked whether it is possible to nucleate surface nanobubbles to visible sizes. According... 

Figure 7.15 Volume vs. radius of artifical (green) and natural (blue) surface nanobubbles. While the former do cavitate for a large enough pressure reduction, the latter do not, though they are of a similar size and volume.

Electrolysis A Controlled and Reproducible Way to Create Surface Nanobubbles... 

A well-known method to produce gas at solid-liquid interfaces is through electrolysis. What happens here at the nanoscale Yang et al could monitor the growth of gaseous surface nanobubbles in real time using AFM, when the sample surface acted as of the hydrogen-producing electrode. A typical result of that experiment, at 1V, is shown in Fig. 7.17. 

Figure 7.18 Electrol5 tically generated hydrogen surface nanobubbles Cleft) and the time evolution of the current toward that situation at 1.5 V and 2.0 V Cright] [figures taken from. )...

---