A sorbent is a material used to absorb or adsorb liquids or gases. Examples include: *A material similar to molecular sieve material, which acts by adsorption (attracting molecules to its surface). It has a large internal

surface area The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc ...

and good thermal conductivity. It is typically supplied in pellets of 1 mm to 2 mm diameter and roughly 5 mm length or as grains of the order 1 mm. Occasionally as beads up to 5 mm diameter. They are typically made from aluminium oxide with a porous structure. *Materials used to absorb other materials due to their high affinity for doing so. Examples include: **In composting, dry (brown, high-

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...

) materials absorb many odoriferous chemicals, and these chemicals help to decompose these sorbents. **A sponge absorbs many times its own weight in water. **A polypropylene fiber mat may be used to absorb oil. **A

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

fiber product may be used to absorb oil. **The granular gel material in a baby diaper will absorb several times its original weight in urine. ** Desiccants attract water, drying out (

desiccating Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. ...

) the surrounding materials.

Method of action

When used in a chemical spill acting as a sorbent, oil-absorbent pads must attract oil preferentially to water i.e. – it should be oleophilic and hydrophobic. Sorbent materials must act by adsorption or less commonly by absorption. Both adsorb material, as well as absorbents, incorporate the oil or other liquid to be recovered into the body of the material.

References

Desiccants Natural materials Synthetic materials {{Material-stub