Dictionary:

detergent

  (dĭ-tûr'jənt)

A cleansing substance that acts similarly to soap but is made from chemical compounds rather than fats and lye.

Having cleansing power.

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Soap, the sodium salt of long-chain acids, was the principal detergent until superseded in 1954 by synthetic detergents (syndets) which, unlike soap, do not form insoluble products with the calcium in hard water.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 Alkyl benzene sulfonates (ABS) with branched carbon chains were found to persist in wastewater and have been replaced by linear alkyl benzene sulfonates (LAS), which are biodegradable by bacterial action.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.

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 more information on detergent, visit Britannica.com.

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.

Laundry detergents are just one of many possible uses for detergents

Detergent is a compound, or a mixture of compounds, intended to assist cleaning. The term is often used to differentiate between soap and other chemical surfactants used for cleaning purposes.

Composition

Detergents, especially those made for use with water, often include different components such as:

• Surfactants to 'cut' grease and to wet surfaces
• Abrasive to scour
• Substances to modify pH or to affect performance or stability of other ingredients, acids for descaling or caustics to breakdown organic compounds
• Water softeners to counteract the effect of "hardness" ions on other ingredients
• oxidants (oxidizers) for bleaching, disinfection, and breaking down organic compounds
• Non-surfactant materials that keep dirt in suspension
• Enzymes to digest proteins, fats, or carbohydrates in stains or to modify fabric feel
• Ingredients that modify the foaming properties of the cleaning surfactants, to either stabilize or counteract foam
• Ingredients that affect the aesthetic properties, such as optical brighteners, fabric softeners, colors, perfumes, etc.
• Washing agents may contain soap for the purpose of reducing foam rather than cleaning fabric.

Detergent Choice

There are several factors which dictate what compositions of detergent should be used, including the material to be cleaned, the apparatus to be used, and tolerance for and type of dirt. For instance, all of the following are used to clean glass. The sheer range of different detergents which can be used demonstrates the importance of context in the selection of an appropriate glass-cleaning agent:

• a chromic acid solution—to get glass very clean for certain precision-demanding purposes, namely in analytical chemistry;
• a high foaming mixture of surfactants with low skin irritation—for hand washing of drink glasses in a sink or dishpan;
• other surfactant-based compositions—for washing windows with a squeegee, followed by rinsing;
• any of various non-foaming compositions—for glasses in a dishwashing machine;
• an ammonia-containing solution—for cleaning windows with no additional dilution and no rinsing;
• ethanol or methanol in Windshield washer fluid—used for a vehicle in motion, with no additional dilution.

Terminology

Sometimes the word "detergent" is used in distinction to "soap". For a while during the infancy of other surfactants as commercial detergent products, the term "syndet", short for "synthetic detergent" was promoted to indicate this, but never caught on very well, and is incorrect in any event because soap is itself synthesized via saponification of glycerides. The term "soapless soap" also saw a brief vogue. Unfortunately, there is no accurate term for detergents not made of soap other than "soapless detergent" or "non-soap detergent". These detergents actually contain equal if not greater amounts of synthesized soap than the regular "detergent".

Also, the term "detergent" is sometimes used for surfactants in general, even when they are not used for cleaning. As can be seen above, this too is terminology that should be avoided as long as the term "surfactant" itself is available.

Technically, plain water, if used for cleaning, is a detergent. Probably the most widely used detergents other than water are soaps or mixtures composed chiefly of soaps. However, not all soaps have significant detergency. Often the word "soap" is used to indicate any detergent, especially those that have characteristics similar to those of soap.

See also

• Biological detergent
• Household chemicals
• Laundry detergent
• Soap
• Organic Chemistry

http://chemistry.about.com/od/howthingswork/f/detergentfaq.htm

Sources

• Much of the information of this page was derived from: Detergents guide

External links

• Detergent compositions or components

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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