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Adsorption

Langmuir: θ = KP/(1+KP); BET isotherm for multilayer
Quick Reference
Formula / NotationLangmuir: θ = KP/(1+KP); BET isotherm for multilayer
Also Known AsSurface adsorption; physisorption; chemisorption; sorption (general term including adsorption + absorption)

What is Adsorption?

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid onto a solid or liquid surface. The adsorbed material is called the adsorbate and the surface is called the adsorbent. It is distinct from absorption (where molecules penetrate into the bulk of the material). Physisorption involves weak van der Waals forces; chemisorption involves chemical bonding.

Formula & Notation

Langmuir: θ = KP/(1+KP); BET isotherm for multilayer

Other Names / Synonyms: Surface adsorption; physisorption; chemisorption; sorption (general term including adsorption + absorption)

Properties & Characteristics

Surface phenomenon; exothermic process; characterised by adsorption isotherms (Langmuir, Freundlich, BET); physisorption (van der Waals) vs. chemisorption (chemical bonds); measured by surface area (BET method); reversible (physi) or irreversible (chemi)

Uses & Applications

Activated carbon filters for water and air purification; chromatography (stationary phase adsorption); catalysis (reactants adsorb on catalyst surface); gas masks and respirators; removing pollutants from wastewater; pharmaceutical drug delivery

Safety Information

Adsorption processes themselves are generally safe. However, activated carbon and zeolites can adsorb toxic gases — spent adsorbents must be disposed of carefully. Some adsorbents (silica gel with indicator) may contain toxic compounds.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Adsorption
Formula Langmuir: θ = KP/(1+KP); BET isotherm for multilayer
Synonyms Surface adsorption; physisorption; chemisorption; sorption (general term including adsorption + absorption)

Frequently Asked Questions

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid onto a solid or liquid surface. The adsorbed material is called the adsorbate and the surface is called the adsorbent. It is distinct from absorption (where molecules penetrate into the bulk of the material). Physisorption involves weak van der Waals forces; chemisorption involves chemical bonding.

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