Interfacial polygonal nanopatterning of stable microbubbles

Micrometer- sized bubbles are unstable and therefore difficult to make and store for substantial lengths of time. Short- term stabilization is achieved by the addition of amphiphilic molecules, which reduce the driving force for dissolution. When these molecules crystallize on the air/ liquid interface, the lifetime of individual bubbles may extend over a few months. We demonstrated low gas- fraction dispersions with mean bubble radii of less than 1 micrometer and stability lasting more than a year. An insoluble, self- assembled surfactant layer covers the surface of the microbubbles, which can result in nanometer- scale hexagonal patterning that we explain with thermodynamic and molecular models. The elastic response of the interface arrests the shrinkage of the bubbles. Our study identifies a route to fabricate highly stable dispersions of microbubbles.