Generation of superstable, monodisperse microbubbles using a pH-driven assembly of surface-active particles.

Bubbling to the surface: Microscale gas bubbles can be generated in a microfluidic device by simultaneously injecting CO(2) and a dispersion of particles whose hydrophobicity increases as the pH value decreases. The CO(2) dissolves rapidly out of the bubbles, which shrink, and render the dispersion increasingly acidic. This drives the particles to the bubble surface where they form a type of "armor" against further dissolution (see picture).