adsorbite

Adsorbite is a term used in adsorption science to denote the species that is adsorbed onto a solid surface during adsorption processes. In English, the more common term is adsorbate. The solid surface hosting the interaction is called the adsorbent. Adsorption refers to the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved phase onto the interface, forming a surface layer rather than penetrating into the bulk.

Two main bonding mechanisms govern adsorption: physisorption, driven by weak van der Waals forces and typically reversible, and chemisorption, involving stronger chemical bonds and often more irreversible. The extent and nature of adsorption depend on temperature, pressure, surface area, porosity, and the chemical compatibility of the adsorbate with the adsorbent.

Adsorption isotherms describe how the amount adsorbed varies with pressure (or concentration) at a given temperature. Common models include Langmuir, which assumes a single, uniform monolayer on a homogeneous surface, and Freundlich, which accounts for surface heterogeneity. Characterization often uses gas adsorption techniques to determine surface area (for example via the BET method) and adsorption capacity, which relates to surface coverage.

Examples include CO2 on activated carbon, water vapor on silica gel, and dye molecules on clays. Applications span environmental cleanup, gas separation and storage, catalysis, sensors, and material design. Etymology traces to Latin ad- “to” and sorbere “to suck up.” In some languages, adsorbite is used to denote the adsorbate, while in English the preferred term is adsorbate.