Interface

An interface is the region that separates two bulk phases. An interface is a molecular structure, given that one of its characteristic lengths is of molecular size. It is therefore non-trivial to precisely define the intrinsic surface, the mathematical surface that describes the interface at the microscopic level. The cost in terms of the Helmholtz energy to create such a structure is known as the the surface tension. The simplest, most studied, and perhaps most important interface is the fluid/fluid interface: the liquid/vapour interface of a one-component system. Interfaces are subject to thermal noise, which leads to thermal capillary waves.

See also

• Capillary fluctuation method
• Cleaving method
• Diffusion at interfaces
• Surface tension

References

Related reading

• R. Evans "The nature of the liquid-vapour interface and other topics in the statistical mechanics of non-uniform, classical fluids", Advances in Physics 28 pp. 143-200 (1979)