adsorption, adhesion of the molecules of liquids, gases, and dissolved substances to the surfaces of solids, as opposed to absorption absorption [Lat.,=sucking from], taking of molecules of one substance directly into another substance. It is contrasted with adsorption , in which the molecules adhere only to the surface of the second substance.
..... Click the link for more information. , in which the molecules actually enter the absorbing medium (see adhesion and cohesion adhesion and cohesion, attractive forces between material bodies. A distinction is usually made between an adhesive force, which acts to hold two separate bodies together (or to stick one body to another) and a cohesive force, which acts to hold together the like or
..... Click the link for more information. ). Certain solids have the power to adsorb great quantities of gases. Charcoal, for example, which has a great surface area because of its porous nature, adsorbs large volumes of gases, including most of the poisonous ones, and is therefore used in gas masks. Certain finely divided solids have great adsorptive properties; for example, minute particles of platinum attract and hold multitudes of hydrogen molecules on their surfaces. Its ability to adsorb other gases makes platinum very useful in the production of sulfuric acid by the contact process and in the preparation of ammonia. Adsorption occurs also in solutions; colloidal particles suspended in a solution may adsorb much of the solvent (see colloid colloid (kŏl`oid) [Gr.,=gluelike], a mixture in which one substance is divided into minute particles (called colloidal particles) and
..... Click the link for more information. ). Bone black and charcoal are used in industry to remove colors from solutions, since they adsorb many coloring materials and carry these with them when separated from the solution. Liquid dye held to the surface of cloth by adsorption permeates the fibers so that when the liquid has evaporated the dye still remains. Adsorption is employed in the hydrogenation of oils, in gas analysis, and in chromatography, a method used in the chemical analysis of closely related substances.

adsorption

Capability of a solid substance (adsorbent) to attract to its surface molecules of a gas or solution (adsorbate) with which it is in contact. Physical adsorption depends on van der Waals forces of attraction between molecules and resembles condensation of liquids. In chemical adsorption (often called chemisorption; see catalysis), the gas is held to the surface by chemical forces specific to the chemicals involved, and formation of the bond may require an activation energy.

adsorption [ad′sȯrp·shən]

(chemistry)

The surface retention of solid, liquid, or gas molecules, atoms, or ions by a solid or liquid, as opposed to absorbtion, the penetration of substances into the bulk of the solid or liquid.

adsorption (redirected from Adsorbtion)

adsorption

adsorption
(redirected from Adsorbtion)