bombolles

Bombolles is the Catalan term for bubbles, referring to gas-filled spheres enclosed by a liquid film. The concept applies across natural phenomena and man-made processes, from carbonated beverages to soap foams. Bubble size spans several orders of magnitude, from micrometres in drinks to centimetres in foams.

Bubbles form when a gas comes out of solution or is introduced into a liquid, nucleating on impurities, surfaces, or gas supersaturation. The stability of a bubble is governed by surface tension and the presence of surfactants, which strengthen the liquid film and slow drainage. The internal pressure of a bubble exceeds the surrounding liquid due to Laplace pressure, with smaller bubbles having higher internal pressure and a tendency to dissolve.

Bubbles rise or float depending on density differences, causing buoyant motion in liquids. They may coalesce when they collide, forming larger bubbles, or dissolve if gas diffuses back into the liquid. In foams, a continuous phase of bubbles is stabilized by surfactants or polymers, creating a complex, sponge-like structure.

Applications and occurrences include carbonated drinks, beer and sparkling wines, soapy lathers, and culinary foams. In industry, bubbles are used in froth flotation to separate minerals and in chemical reactors, where gas-liquid contact is essential. In science and medicine, microbubbles serve as ultrasound contrast agents, while cavitation refers to the rapid formation and collapse of bubbles under changing pressure.

See also: perlage, foam, cavitation.