Semi-permeability

Schematic representation of a semipermeable membrane: The membrane (yellow) separates the two compartments (red and blue). Small components (shown in yellow, green and pink) can pass through the membrane; large cells (left compartment, shown in red) are retained.

With semi-permeability ( lat. Semi , half, partly 'and permeare , runaway, wander happen'; see also permeability ) is defined as the property of substantial or physical interfaces (often membranes ), "semi-transparent" or to be "partially transparent".

In the simplest definition, a semipermeable membrane is used when the membrane allows the solvent but not the solute to pass through. In more general terms, only molecules below a certain molar mass or colloids or particles below a certain size are allowed through.

Semi-permeability is the basis for the osmosis process , which takes place in the cells of all organisms and is also used for technical applications such as the osmosis power plant. Semi-permeability is also used for what is known as reverse osmosis , for example for water treatment and seawater desalination .

This form of membrane is also used in fuel cells .

See also

• Selective permeability
• Cell membrane
• Membrane technology

Web links

Wiktionary: Semipermeability  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ↑ Horst Bannwarth, Bruno P. Kremer, Andreas Schulz: Basic knowledge of physics, chemistry and biochemistry . Springer, Berlin, Heidelberg 2013, ISBN 978-3-642-36635-2 , pp. 192 f ., doi : 10.1007 / 978-3-642-36635-2 .