Membrane
From Wikipedia, the free encyclopedia
A membrane is a layer of material which serves as a selective barrier between two phases and remains impermeable to specific particles, molecules, or substances when exposed to the action of a driving force. Some components are allowed passage by the membrane into a permeate stream, whereas others are retained by it and accumulate in the retentate stream.[1]
Membranes can be of various thickness, with homogeneous or heterogeneous structure. Membrane can also be classified according to their pore diameter. According to IUPAC, there are three different types of pore size classifications: microporous (dp < 2nm), mesoporous (2nm < dp < 50nm) and macroporous (dp > 50nm).[2] Membranes can be neutral or charged, and particles transport can be active or passive. The latter can be facilitated by pressure, concentration, chemical or electrical gradients of the membrane process. Membranes can be generally classified into three groups: inorganic, polymeric or biological membranes. These three types of membranes differ significantly in their structure and functionality.[3]
Contents |
[edit] Biological
[edit] Artificial
[edit] Polymeric
[edit] Membranes in Popular Culture
Membranes were mentioned in the Cypress Hill song "Insane in the Brain." The chorus features B-Real repeating the title of the song but, in a nonsensical though thematically appropriate fashion, replacing the word "brain" with "membrane."
[edit] See also
- Basement membrane
- Cell membrane
- Inner membrane
- Membrane (M-Theory)
- Mucous membrane
- Outer membrane
- Serous membrane
- Vibrations of a circular drum
[edit] References
- ^ Zydney, Andrew L.; Zeman, Leos J. (1996). Microfiltration and ultrafiltration: principles and applications. New York: CRC. ISBN 0-8247-9735-3.
- ^ Macroporous Materials Containing Three Dimensional Periodic Structures
- ^ Mulder, Marcel (1996). Basic principles of membrane technology (2 ed.). Kluwer Academic: Springer. ISBN 0-7923-4248-8.
