Adsorption
Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the
adsorbate on the surface of the
adsorbent. This process differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid. Adsorption is a surface-based process while absorption involves the whole volume of the material. The term
sorption encompasses both processes, while
desorption is the reverse of it. Adsorption is a
surface phenomenon. IUPAC Definition Increase in the concentration of a substance at the interface of a condensed and a liquid or gaseous layer owing to the operation of surface forces. Note 1: Adsorption of proteins is of great importance when a material is in contact with blood or body fluids. In the case of blood, albumin, which is largely predominant, is generally adsorbed first, and then rearrangements occur in favor of other minor proteins according to surface affinity against mass law selection. Note 2: Adsorbed molecules are those that are resistant to washing with the same solvent medium in the case of adsorption from solutions.