Sorbent
Encyclopedia
A sorbent is a material used to absorb liquids or gases. Examples include:
- A material similar to molecular sieveMolecular sieveA molecular sieve is a material containing tiny pores of a precise and uniform size that is used as an adsorbent for gases and liquids.Molecules small enough to pass through the pores are adsorbed while larger molecules are not. It is different from a common filter in that it operates on a...
material. It has a large internal surface areaSurface areaSurface area is the measure of how much exposed area a solid object has, expressed in square units. Mathematical description of the surface area is considerably more involved than the definition of arc length of a curve. For polyhedra the surface area is the sum of the areas of its faces...
and good thermal conductivityThermal conductivityIn physics, thermal conductivity, k, is the property of a material's ability to conduct heat. It appears primarily in Fourier's Law for heat conduction....
. 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 oxideAluminium oxideAluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...
with a porous structure. - Materials used to absorb other materials due to their high affinityChemical affinityIn chemical physics and physical chemistry, chemical affinity is the electronic property by which dissimilar chemical species are capable of forming chemical compounds...
for doing so. Examples include:- In composting, dry (brown, high-carbonCarbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
) materials absorb many odoriferous chemicals, and these chemicals help to decompose these sorbents. - A sponge absorbs many times its own weight in water.
- A polypropylenePolypropylenePolypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
fiber mat may be used to absorb oil. - A celluloseCelluloseCellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
fiber product may be used to absorb oil. - The granular gel material in a baby diaperDiaperA nappy or a diaper is a kind of pant that allows one to defecate or urinate on oneself discreetly. When diapers become soiled, they require changing; this process is often performed by a second person such as a parent or caregiver...
will absorb several times its original weight in urineUrineUrine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
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- In composting, dry (brown, high-carbon