Sorptive

Sorbive is an adjective relating to sorption, the process by which a substance, called the sorbate, is taken up at a boundary or within a material. Sorption encompasses two related phenomena: adsorption, where molecules adhere to a surface, and absorption, where molecules are taken up and distributed within the bulk of a material. The term is used across chemistry, environmental science, and engineering to describe how substances accumulate at interfaces or inside solids or liquids.

Adsorption refers to the adherence of molecules to a surface via interfacial forces such as van der Waals interactions or chemical bonds, forming a thin film. Absorption involves the penetration and distribution of sorbate throughout the interior of the sorbing phase. Sorption can be physical (physisorption) or chemical (chemisorption), with chemisorption typically stronger and sometimes involving chemical reactions.

Material properties strongly influence sorption behavior. High surface area and porosity increase adsorption capacity, while functional groups on a surface enable specific interactions with certain sorbate molecules. Temperature, pressure, and the chemical nature of both sorbate and sorbent determine the extent and reversibility of sorption. Desorption is the reverse process, allowing regeneration of sorbents for repeated use.

Common sorbents include activated carbon, zeolites, silica gels, and various resins and polymeric materials; desiccants such as silica gel and calcium chloride also operate via sorption. Applications span environmental cleanup (air and water purification), gas capture, separation and catalysis, chromatography, and moisture control in packaging and storage.

Sorption is typically characterized by sorption isotherms and related models (e.g., Langmuir, Freundlich, BET) that describe how sorbate uptake varies with concentration, pressure, or humidity.