The nanobubble story

The existence of gaseous nanobubbles accumulated at the hydrophobic solid–liquid interface has been under intense debate over the last two decades. This entry provides details of the experimental development of nanobubbles and eliminates any remaining speculation on the gaseous nature of such domains. Experimental findings leading to rejections of nanobubble existence are based on systems in which nanobubble formation is not favorable. Surface preparation and experimental methods need to be carefully considered if systematic studies of nanobubbles and resulting forces are to be completed. Despite experimental maturity, a theoretical understanding of nanobubbles is still under development. Therefore, the contentious issue of nanobubble theory will only be briefly discussed.