Adsorption Definition

Adsorption is the process of adhesion of molecules of liquid or gases onto the surface of a solid particle.

• This is the ability of solid particles/surfaces to attract the molecules of liquid and gas towards their surface after they come in contact with the molecules.
• Adsorption is a surface phenomenon where the molecules form a layer of adsorbate around the adsorbent.
• The process of adsorption occurs due to the surface energy where the attachment is facilitated either by Van der Wall’s force or by covalent bonds depending on the nature of the substances involved.
• In physical adsorption molecules are attached to each other simply by Van der Wall force of attraction and no chemical specificity is present between the particles.
• In chemical adsorption, however, bonds are formed between the adsorbate and the adsorbent and the bonds are specific for each adsorbate-adsorbent combination.
• Adsorption is widely utilized in various separation techniques like adsorption chromatography and ion-exchange chromatography.
• These processes allow the separation of molecules by selectively transferring the molecules of the liquid phase onto the surface of solid adsorbent.
• Adsorption is also utilized by viruses where they attach to the surface of either bacteria or other organisms before penetration.
• Adsorption is affected by a number of factors depending on the nature of the substances involved.
• Some common factors include pressure, temperature, area of contact, and the nature of the interaction between the adsorbent and the adsorbate.
• The process of adsorption is always exothermic as it leads to a decrease in the residual forces on the surface of the adsorbate.