detergent

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A substance used to enhance the cleansing action of water. A detergent is an emulsifier, which penetrates and breaks up the oil film that binds dirt particles, and a wetting agent, which helps them to float off. Emulsifier molecules have an oillike nonpolar portion which is drawn into the oil, and a polar group that is water-soluble; by bridging the oilwater interface, they break the oil into dispersible droplets (emulsion). As a surfactant, a detergent decreases the surface tension of water and helps it penetrate soil.

Soap, the sodium salt of long-chain acids, was the principal detergent until superseded in 1954 by synthetic detergents (syndets) which, unlike soap, do not form insoluble products with the calcium in hard water. Most syndets are of the anionic type, that is, sodium salts of alkyl sulfates or sulfonates. Alkyl benzene sulfonates (ABS) with branched carbon chains were found to persist in wastewater and have been replaced by linear alkyl benzene sulfonates (LAS), which are biodegradable by bacterial action. Anionic detergents are best for water-absorbing fibers such as cotton, wool, and silk. Nonionic detergents are polyethers made by combining ethylene oxide with a 12-carbon lauryl alcohol. They are used for water-repelling “permanent press” fabrics, and their low-foaming property is desirable for automatic washers. Cationic syndets are quarternary base compounds. They are more expensive, but some are germicidal; some are used as fabric softeners and as good metal cleaners.

Detergents must contain alkaline “builders” to bind dissolved metal ions and support emulsification. Sodium pyrophosphate or polyphosphate were preferred because of low cost and high cleansing effectiveness. However, when discharged with laundry wastewater, these compounds supply nutrient to phosphate-deficient lakes and streams and thus lead to eutrophication, and their use is now banned by law. Less harmful, but less effective, builders such as sodium carbonate are now widely used in detergents. See also Eutrophication.

Many additives are used in detergents to provide scent, brightening (usually through fluorescent action), or bleaching action. Biodegradability is essential for detergents; it ensures that components of detergents will be broken down by bacterial action before undesirable aftereffects can occur. Nonbiodegradable detergents can prevent effective bacterial action in septic tanks and sewage treatment plants, and can cause undesirable persistent foaming in rivers. See also Soap.

1. a cleansing agent, especially a soap or (usually synthetic) soaplike substance that, when used in aqueous solution, cleanses by reducing surface tension.
2. having the properties of a detergent. See also BigCHAP, Brij, C_x E_y, cetyltrimethylammonium bromide, CHAPS, CHAPSO, cholic acid, n-decyl-β-d-glucopyranoside, n-decyl-β-d-maltopyranoside, deoxyBigCHAP, deoxycholic acid, digitonin, dodecylglucopyranoside, dodecylmaltoside, n-dodecyl-N, N-dimethylglycine, Genapol, glycocholate, glycodeoxycholate, heptyl glucoside, heptyl thioglucoside, hexyl glucoside, lauryldimethylamine oxide, sodium dodecylsulfate, Lubrol, Mega-8, nonyl glucoside, NP-40, octyl glucoside, octyl thio-glucoside, taurocholate, taurodeoxycholate, Triton, Tween, Zwittergent.

1. purifying, cleansing.
2. an agent that purifies or cleanses.

• anionic d. — a substance which when dissolved contributes a hydrophobic ion which carries a negative charge to the solution. Soap is an example.
• cationic d. — the dissociated substance produces a positively charged hydrophobic ion. The quarternary ammonium compounds are the best known examples. They are innocuous if properly diluted but the concentrates are very poisonous.
• nonionic surface-acting d. — e.g. the polyoxyethylenes are regarded as nonpoisonous.

A cleanser Also applied in a more specific sense to chemicals that possess surfaceactive properties in water and whose solutions are therefore able to wet surfaces that are normally water repellent, thereby assisting in the mechanical dispersion and emulsifica-tion of fatty or oily material and other substances that soil the surface.

For the band, see The Detergents.

Detergents

A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions."^[1] In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water. In most household contexts, the term detergent by itself refers specifically to laundry detergent or dish detergent, as opposed to hand soap or other types of cleaning agents. Detergents are commonly available as powders or concentrated solutions. Detergents work because they are amphiphilic - partly hydrophilic (polar) and partly hydrophobic (non-polar). Their dual nature facilitates the mixture of hydrophobic compounds (like oil and grease) with water. Because air is not hydrophillic, detergents are also foaming agents to varying degrees. Completely non-polar solvents known as degreasers can also remove hydrophobic contaminants but may not dissolve in water because of a lack of polar elements.

Contents 1 Chemical classification of detergents 1.1 Anionic detergents 1.2 Cationic detergents 1.3 Non-ionic and zwitterionic detergents 2 Major applications of detergents 2.1 Laundry detergents 2.2 Fuel additives 2.3 Soapless soap 3 See also 4 References 5 External links

Chemical classification of detergents

Detergents are classified into three broad groupings, depending on the electrical charge of the surfactants.

Anionic detergents

Typical anionic detergents are alkylbenzenesulfonates. The alkylbenzene portion of these anions is lipophilic and the sulfonate is hydrophilic. Two varieties have been popularized, those with branched alkyl groups and those with linear alkyl groups. The former were largely phased out in economically advanced societies because they are poorly biodegradable.^[2] An estimated 6 billion kilograms of anionic detergents are produced annually for domestic markets.

Bile acids, such as deoxycholic acid (DOC), are anionic detergents produced by the liver to aid in digestion and absorption of fats and oils.

Three kinds of anionic detergents: a branched sodium dodecylbenzenesulfonate, linear sodium dodecylbenzenesulfonate, and a soap.

Cationic detergents

Cationic detergents are similar to the anionic ones, with a hydrophobic component, but, instead of the anionic sulfonate group, the cationic surfactants have quaternary ammonium as the polar end. The ammonium center is positively charged.^[2]

Non-ionic and zwitterionic detergents

Non-ionic detergents are characterized by their uncharged, hydrophilic headgroups. Typical non-ionic detergents are based on polyoxyethylene or a glycoside. Common examples of the former include Tween, Triton, and the Brij series. These materials are also known as ethoxylates or PEGylates). Glycosides have a sugar as their uncharged hydrophilic headgroup. Examples include octyl-thioglucoside and maltosides. HEGA and MEGA series detergents are similar, possessing a sugar alcohol as headgroup.

Zwitterionic detergents possess a net zero charge arising from the presence of equal numbers of +1 and -1 charged chemical groups. Examples include CHAPS.

See surfactants for more applications.

Major applications of detergents

Laundry detergents

Main article: laundry detergent

One of the largest applications of detergents is for cleaning clothing. The formulations are complex, reflecting the diverse demands of the application and the highly competitive consumer market. In general, laundry detergents contain water softeners, surfactants, bleach, enzymes, brighteners, fragrances, and many other agents. The formulation is strongly affected by the temperature of the cleaning water and varies from country to country.

Fuel additives

Both carburetors and fuel injector components of Otto engines benefit from detergents in the fuels to prevent fouling. Concentrations are about 300 ppm. Typical detergents are long-chain amines and amides such as polyisobuteneamine and polyisobuteneamide/succinimide.^[3]

Soapless soap

Soapless soap refers to a soapfree liquid cleanser with a slightly acidic pH.^[4] Soapless soaps are used in an array of products.

Borax-based washing detergent

See also

• Laundry detergent
• Dishwashing liquid
• Hard-surface cleaner
• Cleavable detergent
• Dispersant

References

1. ^ http://goldbook.iupac.org/D01643.html
2. ^ ^{a b} Eduard Smulders, Wolfgang Rybinski, Eric Sung, Wilfried Rähse, Josef Steber, Frederike Wiebel, Anette Nordskog, "Laundry Detergents" in Ullmann’s Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a08_315.pub2
3. ^ Werner Dabelstein, Arno Reglitzky, Andrea Schütze, Klaus Reders "Automotive Fuels" in Ullmann’s Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheimdoi:10.1002/14356007.a16_719.pub2
4. ^ Tyebkhan G (2002), "Skin cleansing in neonates and infants-basics of cleansers", Indian J Pediatr 69 (9): 767–9, doi:10.1007/BF02723687, PMID 12420908, http://www.springerlink.com/content/61r261h452j3w70m/. 

External links

Wikimedia Commons has media related to: Detergents

• About.com: How Do Detergents Clean
• Detergents and Surfactants

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - rensemiddel, sulfo
adj. - rense-, vaske-

Nederlands (Dutch)
wasmiddel

Français (French)
n. - détergent
adj. - détergent, détersif

Deutsch (German)
n. - Waschmittel, Spülmittel, Reinigungsmittel
adj. - reinigend

Ελληνική (Greek)
n. - απορρυπαντικό, σκόνη μπουγάδας

Italiano (Italian)
detergente

Português (Portuguese)
n. - detergente (m)

Русский (Russian)
стиральный порошок

Español (Spanish)
n. - detergente
adj. - detergente

Svenska (Swedish)
n. - tvättmedel, rengöringsmedel

中文（简体）(Chinese (Simplified))
清洁剂, 去垢的, 使洁净的

中文（繁體）(Chinese (Traditional))
n. - 清潔劑
adj. - 去垢的, 使潔淨的

한국어 (Korean)
n. - 합성 세제
adj. - 깨끗이 세정하는

日本語 (Japanese)
adj. - 洗浄性の
n. - 洗浄剤, 洗剤, 清浄剤

العربيه (Arabic)
‏(الاسم) مادة منظفه, مادة مطهرة‏

עברית (Hebrew)
n. - ‮תכשיר ניקוי, דטרגנט‬
adj. - ‮מטהר‬

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