I. The similarity between bulk nanobubbles and microemulsions. (b) shows nanobubble-containing aqueous solution that coexists with an excess gas phase. For the oil-in-water microemulsion, the oil droplet (colored in yellow) is encapsulated with a surfactant monolayer in a continuous phase of water, while for the bulk nanobubble, it is the gas bubble is encapsulated with a compressed amphiphile monolayer in the aqueous solution. In both cases, amphiphile molecules (or surfactants composed of a hydrophilic head in red and a hydrophobic tail in black) play an important role in their stability. Our previous simulations indicate that surfactants in the monolayer are in fact in a disordered state.