A sorbent is a material that either absorbs or adsorbs liquids or gases.^[1]

Examples

Sorbents come in various forms and materials, including:

• Similar to molecular sieve material, a sorbent may function via adsorption, attracting molecules to its surface. These are typically supplied in pellets (1mm to 2mm diameter, approximately 5mm length) or grains (~1mm), occasionally as beads up to 5mm in diameter, and are commonly made from aluminium oxide featuring a porous structure.
• Materials with a high affinity for absorbing other materials, such as:
  • Dry, high-carbon materials used in composting to absorb odoriferous chemicals, which assist in decomposing the sorbents.
  • Sponges, which can absorb many times their own weight in water.
  • Polypropylene fiber mats, which can be employed to absorb oil.
  • Cellulose fiber products used for oil absorption.
  • The granular gel material in baby diapers, capable of absorbing multiple times its original weight in urine.
  • Desiccants, which attract water, thereby drying (desiccating) surrounding materials.

Method of action

In instances of chemical spills where sorbents are utilized, oil-absorbent pads should exhibit oleophilic (oil-attracting) and hydrophobic (water-repelling) properties. Sorbent materials operate primarily through adsorption, and less frequently, by absorption. Both mechanisms involve the incorporation of the oil or another liquid into the material's structure, though the methods of incorporation differ.^[2]