Shape dynamics of nanobubbles located on bunched and wide terraces at highly oriented pyrolytic graphite/water-ethanol interface Shape Dynamics of Nanobubbles Located on Bunched and Wide Terraces at Highly Oriented Pyrolytic Graphite/Water–Ethanol Interface

The time courses of the nanobubbles were investigated on a highly oriented pyrolytic graphite (HOPG) surface contacting with the air-saturated water-ethanol mixture. On a high step density surface, bubbles were confined within a narrow bunched terrace, and coalesced to form an elliptic bubble. The final volume of the coalesced bubble was larger than that of the sum of the initial individual bubbles. On a ider terrace, the volume of a solitary hemispherical bubble changed stochastically and the larger volume fluctuation accompanied a smaller bubble.

The time courses of the nanobubbles were investigated on a highly oriented pyrolytic graphite (HOPG) surface contacting with the air-saturated water–ethanol mixture. On a high step density surface, bubbles were confined within a narrow bunched terrace, and coalesced to form an elliptic bubble. The final volume of the coalesced bubble was larger than that of the sum of the initial individual bubbles. On a wider terrace, the volume of a solitary hemispherical bubble changed stochastically and the larger volume fluctuation accompanied a smaller bubble.