Pore

Name:
Pore
Detailed information:
(1) A minute cavity in epidermal tissue as in skin, leaves, or leather, having a capillary channel to the surface that permits transport of water vapor from within outward but not the reverse.(2) A void or interstice between particles of a solid such as sand minerals or powdered metals, that permits passage of liquids or gases through the material in either direction. In some structures, such as gaseous diffusion barriers and molecular sieves, the pores are of molecular dimensions, i.e., 4–10 Å units. Such microporous structures are useful for filtration and molecular separation purposes in various industrial operations. (3) A cell in a spongy structure made by gas formation (foamed plastic) that absorbs water on immersion but releases it when stressed.See Membrane, Semipermeable; Molecular Sieve.