Adsorbans

Adsorbans are atoms, ions, or molecules that are attracted to and held on a solid surface by adsorption. They originate from a surrounding gas or liquid phase and form an adsorbed layer on the surface. In current English usage, the standard term for these species is adsorbates; adsorbans appears mainly in older literature or as a direct translation from other languages.

Adsorption can be physical (physisorption) or chemical (chemisorption). Physisorption involves weak van der Waals interactions and is typically reversible, being strongly influenced by temperature and pressure. Chemisorption involves stronger chemical bonds and can alter the electronic and structural properties of the surface; it is often less reversible and may be selective for specific sites.

To describe how adsorbans populate a surface, researchers use adsorption isotherms such as Langmuir, Freundlich, and BET models. Key concepts include surface coverage, adsorption energy, and the equilibrium between adsorption and desorption. These models help quantify how much material adheres to a surface at given conditions and how this capacity changes with concentration or pressure.

Applications of adsorption span catalysis, environmental remediation (removing pollutants from air or water), separation processes, and sensor technology, where the behavior of adsorbans influences performance and selectivity. Terminology varies by field and language; in contemporary English, adsorbate refers to the adsorbed species, while adsorbent denotes the surface material that mediates adsorption.