Interface

• Date: 1882

Definitions

• 1 : a surface forming a common boundary of two bodies, spaces, or phases <an oil-water interface>
• 2 a : the place at which independent and often unrelated systems meet and act on or communicate with each other <the man-machine interface>

b : the means by which interaction or communication is achieved at an interface

Description (Chemistry)

An interface is a surface forming a common boundary among two different phases, such as an insoluble solid and a liquid, two immiscible liquids or a liquid and an insoluble gas. The importance of the interface depends on which type of system is being treated: the bigger the quotient area/volume, the more effect the surface phenomena will have. Therefore interfaces will be considered in systems with big area/volume ratios, such as colloids.

Interfaces can be spherical or flat, so they can be considered to be always spherical with finite or infinite radius. For example oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat.

Surface tension {see Superficial) is the function which rules interface processes.

Interfaces may cause various optical phenomena, such as refraction. Optical lenses serve as an example of a practical application of the interface between glass and air.

One important interface is the gas liquid interface between aerosols and other atmospheric molecules.