phenomenaadsorption

Adsorption is a surface phenomenon that occurs when atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to a surface. This process is driven by intermolecular forces and can be physical or chemical in nature. Physical adsorption, also known as physisorption, involves weak van der Waals forces and is often reversible. Chemical adsorption, or chemisorption, involves stronger covalent or ionic bonds and is typically irreversible.

Adsorption is widely used in various applications, including catalysis, gas purification, water treatment, and chromatography. In catalysis, adsorption is crucial for the activation of reactants on the surface of a catalyst. In gas purification, adsorbents like activated carbon and zeolites are used to remove impurities from gases. In water treatment, adsorption is employed to remove contaminants such as heavy metals and organic compounds. Chromatography, a technique used for separating and analyzing compounds, relies on adsorption to distribute components between a stationary phase and a mobile phase.

The adsorption process can be described by the adsorption isotherm, which relates the amount of adsorbate on the adsorbent to the pressure or concentration of the adsorbate at a constant temperature. Common adsorption isotherms include the Langmuir, Freundlich, and BET (Brunauer-Emmett-Teller) isotherms. Each isotherm provides insights into the nature of the adsorption process and the interactions between the adsorbate and the adsorbent.