Note that although the compressed amphiphile monolayer mechanism can explain many experimental observations of nanobubble stability, it does not mean that this model can be applied to all cases of bulk nanobubbles. In particular, for bulk nanobubbles with high interfacial charge density, the zeta potential would play an important role in their stability. For nanobubbles in a solution with high gas supersaturation, similarly the vanishing surface tension and thus the compressed amphiphile monolayer are not needed for their stability.