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: Foam
Famous quotes containing the words structure of, structure and/or foams:
“The verbal poetical texture of Shakespeare is the greatest the world has known, and is immensely superior to the structure of his plays as plays. With Shakespeare it is the metaphor that is the thing, not the play.”
—Vladimir Nabokov (1899–1977)
“I’m a Sunday School teacher, and I’ve always known that the structure of law is founded on the Christian ethic that you shall love the Lord your God and your neighbor as yourself—a very high and perfect standard. We all know the fallibility of man, and the contentions in society, as described by Reinhold Niebuhr and many others, don’t permit us to achieve perfection.”
—Jimmy Carter (James Earl Carter, Jr.)
“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)