Froth

۲٬۵۶۲ طرفدار

۱۴ انتشار • فعال از ۲۰۱۰

Foam is a two-phase material system and a type of dispersed media, consisting of gas cells dispersed in a continuous liquid or solid phase to form a cellular structure. In most foams, the gas occupies most of the volume and is divided into bubbles separated by thin films of liquid or solid material. The formation, stability and properties of foams are studied in physics, physical chemistry and materials science. Foams are classified as liquid or solid foams, which differ in their formation, structure and physical behaviour. Solid foams may be further divided into open-cell and closed-cell structures that differ in their mechanical and transport properties. Foams are formed by dispersing gas into a liquid or solid, typically in the presence of surfactants or other stabilising agents, and their stability depends on factors such as surface tension, the Marangoni effect, drainage, and gas diffusion. Foams have numerous applications, including thermal insulation, packaging, flotation devices, sandwich-structured composite materials, fire retardant foams, froth flotation, foam fractionation, and filtration. Common examples are soap foam, the head on beer, bread, bath sponges, and polymer foams.