Structure of Foams
A foam is in many cases a multiscale system.
One scale is the bubble one: real-life foams are typically disordered and have a variety of bubble sizes. At larger sizes, the study of idealized foams is closely linked to the mathematical problems of minimal surfaces and three-dimensional tessellations, also called honeycombs. The Weaire-Phelan structure is believed to be the best possible (optimal) unit cell of a perfectly ordered foam, while Plateau's laws describe how soap-films form structures in foams.
At lower scale than the bubble one, is the thickness of the film for dry enough foams, which can be considered as a network of interconnected films called lamellae. Ideally, the lamellae are connected by three and radiate 120° outward from the connection points, known as Plateau borders. An even lower scale is the one of the liquid-air interface at the surface of the film. Most of the time this interface is stabilized by a layer of amphiphilic structure, often made of surfactants, particles (Pickering emulsion), or more complex associations.
Read more about this topic: Froth
Famous quotes containing the words structure of, structure and/or foams:
“... the structure of a page of good prose is, analyzed logically, not something frozen but the vibrating of a bridge, which changes with every step one takes on it.”
—Robert Musil (1880–1942)
“If rightly made, a boat would be a sort of amphibious animal, a creature of two elements, related by one half its structure to some swift and shapely fish, and by the other to some strong-winged and graceful bird.”
—Henry David Thoreau (1817–1862)
“This fantastic state of mind, of a humanity that has outrun its ideas, is matched by a political scene in the grotesque style, with Salvation Army methods, hallelujahs and bell-ringing and dervishlike repetition of monotonous catchwords, until everybody foams at the mouth. Fanaticism turns into a means of salvation, enthusiasm into epileptic ecstacy, politics becomes an opiate for the masses, a proletarian eschatology; and reason veils her face.”
—Thomas Mann (1875–1955)