pores
otherwise
caves; cavities; voids
(rus. поры)
—
in physics and chemistry, the gaps or cavities between the structural elements of a solid state of matter; in biology, channels in membranes.
Description
To be distinguished are open (interconnected) pores, which are channels that penetrate the entire volume of a porous body, and closed (non-interconnected ) pores, or cells. The former are characteristic of adsorbents, catalysts, a variety of filter materials, the latter for foams, volcanic glasses, etc. The combined characteristic of size and number of pores in a body, i.e., the total space occupied by pores is called the porosity. It is expressed as the volume of pores per unit volume or mass of the porous body. An indirect characteristic of the size and number of pores is the specific surface of a solid. Small pores can have selectivity for the size of materials adsorbed or transported through the pores (molecular sieve effect). In biological objects, pores perform transport functions, transferring various substances through the membrane or tissue.
Authors
- Andrey V. Smirnov
- Nikolay N. Tolkachev
Sources
- Gregg S. J., Sing K. S. W. Adsorption, Surface Area and Porosity. — Academic Press, NY 1967. — 303 pp.
- Karnaukhov, A. P. Adsorption. Texture of Disperse and Porous Materials (in Russian). — Novosibirsk: Nauka. 1999. — 470 pp.