Laundry detergent

Laundry detergent

Overview

Laundry detergent, or washing powder, is a substance that is a type of detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...

 (cleaning agent) that is added for cleaning laundry
Laundry
Laundry is a noun that refers to the act of washing clothing and linens, the place where that washing is done, and/or that which needs to be, is being, or has been laundered...

. In common usage, "detergent" refers to mixtures of chemical compounds including alkylbenzenesulfonates, which are similar to soap but are less affected by "hard water
Hard water
Hard water is water that has high mineral content . Hard water has high concentrations of Ca2+ and Mg2+ ions. Hard water is generally not harmful to one's health but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling...

." In most household contexts, the term detergent refers to laundry detergent vs hand soap or other types of cleaning agents.
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Encyclopedia

Laundry detergent, or washing powder, is a substance that is a type of detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...

 (cleaning agent) that is added for cleaning laundry
Laundry
Laundry is a noun that refers to the act of washing clothing and linens, the place where that washing is done, and/or that which needs to be, is being, or has been laundered...

. In common usage, "detergent" refers to mixtures of chemical compounds including alkylbenzenesulfonates, which are similar to soap but are less affected by "hard water
Hard water
Hard water is water that has high mineral content . Hard water has high concentrations of Ca2+ and Mg2+ ions. Hard water is generally not harmful to one's health but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling...

." In most household contexts, the term detergent refers to laundry detergent vs hand soap or other types of cleaning agents. Most detergent is delivered in powdered form.

History


From ancient times, chemical additives were recognized for their ability to facilitate the mechanical washing with water. The Italians used a mix of sulfur and water with charcoal to clean cloth. Egyptians added ashes and silicates to soften water. Soaps were the first detergents. The detergent effects of certain synthetic surfactants were noted in Germany in 1917, in response to shortages of soap during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. In the 1930s, commercially viable routes to fatty alcohol
Fatty alcohol
Fatty alcohols are aliphatic alcohols consisting of a chain of 8 to 22 carbon atoms. Fatty alcohols usually have even number of carbon atoms and a single alcohol group attached to the terminal carbon. Some are unsaturated and some are branched...

s were developed, and these new materials were converted to their sulfate esters
Organosulfate
Organosulfates are a class of organic compounds sharing a common functional group commonly with the structure R-O-SO3-. The SO4 core is a sulfate group and the R group is any organic residue. All organosulfates are formally esters derived from alcohols and sulfuric acid, although many are not...

, key ingredients in the commercially important German brand FEWA, produced by BASF
BASF
BASF SE is the largest chemical company in the world and is headquartered in Germany. BASF originally stood for Badische Anilin- und Soda-Fabrik . Today, the four letters are a registered trademark and the company is listed on the Frankfurt Stock Exchange, London Stock Exchange, and Zurich Stock...

, and Dreft
Dreft
Dreft is a popular laundry detergent in the United States, Canada, United Kingdom, the Netherlands and other markets. First produced by Procter & Gamble in 1933, it was one of the earliest synthetic detergents. Upon its inception, Dreft was touted as a significant improvement over the soap suds of...

, the US brand produced by Procter and Gamble. Such detergents were mainly used in industry until after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. By then, new developments and the later conversion of aviation fuel
Aviation fuel
Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures,...

 plants to produce tetrapropylene, used in household
Household chemicals
Household chemicals are chemicals that are commonly found and used in and around the average household. Food additives generally don't fall under this category, unless they have a use other than for human consumption...

 detergents, caused a fast growth of domestic use in the late 1940s.

The use of enzymes for laundry was introduced in the early part of the 1900s by Otto Rohm
Otto Röhm
Otto Karl Julius Röhm was one of the founders and a longtime president of the Röhm und Haas chemical company which became later in the USA the Rohm & Haas PLC and in Germany the Röhm GmbH .- Life :After completion of an apprenticeship as pharmacy assistant he started to study pharmacy at...

. Only in the latter part of the century with the availability of thermally robust bacterial enzymes did this technology become mainstream.

At the present time, soap has largely been displaced as the main cleaning agent in developed countries. Soap is, by weight, relatively ineffective, and it is highly sensitive to deactivation by hard water. By the 1950s, soap had almost been completely replaced by branched alkylbenzenesulfonates, but these detergents were found to be poorly biodegradable. Linear alkylbenzenesulfonates (LABs), however, proved to be both highly effective in cleaning and more biodegradable than the branched relatives. LABs remain the main detergents used domestically. Other detergents that have been developed include the linear alkylsulfonates and olefinsulfonates, which also resist deactivation by hard water. Both remain specialty products, for example only an estimated 60 million kilograms of the sodium alkylsulfonates are produced annually. During the early development of non-soap surfactants as commercial cleaning products, the term syndet, short for synthetic detergent, was promoted to indicate the distinction from so-called natural soaps.

Chemistry of detergents



Many kinds of molecules and ions can serve as high-efficiency surfactant
Surfactant
Surfactants are compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid...

s. They are often classified according to the charge of the molecule or ion, the three main classes being anionic, neutral, and cationic detergents. Anionic detergents are most commonly encountered for domestic laundry detergents. Detergents are ions or molecules that contain both polar and nonpolar components. The polar component allows the detergent to dissolve in the water, whereas the nonpolar portion solubilizes greasy ("hydrophobic") materials that are the usual target of the cleaning process. An estimated 6 billion kilograms of detergents are produced annually for domestic markets.

Components


Modern detergent formulations - the entire product vs just the surfactant - contain several components. Three main ingredients are builders (50% by weight, approximately), the alkylbenzenesulfonate surfactant
Sodium dodecylbenzenesulfonate
Sodium dodecylbenzenesulfonate is a series of organic compounds with the formula C12H25C6H4SO3Na. It is a colourless salt with useful properties as a surfactant. It is usually produced as a mixture of related sulfonates...

 (15%), and bleaches (7%).

Builders


Builders are water softeners. These chemical compounds are agents that remove calcium ions by complexation or precipitation. Typical builders are sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...

, complexation agents, soap, and zeolite
Zeolite
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...

s. They function by sequestering or precipitating the problematic ions. One of the most common builders is sodium triphosphate, which is used on very large scale for this application.

Bleach



The main targets of bleaches are of vegetable origin and include chlorophyll
Chlorophyll
Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...

, anthocyanin
Anthocyanin
Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue according to pH...

 dyes, tannin
Tannin
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...

s, humic acid
Humic acid
Humic acid is a principal component of humic substances, which are the major organic constituents of soil , peat, coal, many upland streams, dystrophic lakes, and ocean water. It is produced by biodegradation of dead organic matter...

s, and
carotenoid
Carotenoid
Carotenoids are tetraterpenoid organic pigments that are naturally occurring in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms like algae, some bacteria, and some types of fungus. Carotenoids can be synthesized fats and other basic organic metabolic building...

 pigments. Most bleaches in laundry detergents are oxidizers, e.g., sodium perborate
Sodium perborate
Sodium perborate is a white, odorless, water-soluble chemical compound with the chemical composition 3. It crystallizes as the monohydrate, NaBO3·H2O, trihydrate, NaBO3·3H2O and tetrahydrate, NaBO3·4H2O. The monohydrate and tetrahydrate are the commercially important forms...

 or sodium hypochlorite, In addition, other agents are added as "bleach activators", to enhance the effectiveness of the bleaching agent; a popular one is tetraacetylethylenediamine
Tetraacetylethylenediamine
Tetraacetylethylenediamine, commonly abbreviated TAED, is an organic compound with the formula 2NCH2CH2N2. Used as peroxide bleach activator for household detergents and for paper pulp. It is produced by acetylation of ethylenediamine....

.

Enzymes



Many laundry detergents contain enzymes. The amounts of enzyme can be up to about 2% by weight of the product. These agents are required to degrade recalcitrant stains composed of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

s, or carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

s. Each type of stain requires a different type of enzyme, i.e., protease
Protease
A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....

 for proteins, lipases for greases, and amylase
Amylase
Amylase is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion. Food that contains much starch but little sugar, such as rice and potato, taste slightly sweet as they are chewed because amylase turns...

s for carbohydrates.

Other ingredients


Many other ingredients are added depending on the specific application. Such additives modify the foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

ing properties of the product by either stabilizing or counteracting foam. Other ingredients increase or decrease the viscosity of the solution, or solubilize other ingredients. Corrosion inhibitors counteract damage to washing equipment. "Dye transfer inhibitors" prevent dyes from one article from colouring other items. "Antiredeposition agents" are used to prevent fine soil particles from reattaching to the product being cleaned. Carboxymethyl cellulose
Carboxymethyl cellulose
Carboxymethyl cellulose or cellulose gum is a cellulose derivative with carboxymethyl groups bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone...

 is used for this purpose.

A number of ingredients affect aesthetic properties of the item to be cleaned or the detergent itself before or during use. These agents include optical brightener
Optical brightener
Optical brighteners, optical brightening agents , fluorescent brightening agents or fluorescent whitening agents are dyes that absorb light in the ultraviolet and violet region of the electromagnetic spectrum, and re-emit light in the blue region...

s, fabric softeners, and colourants. A variety of perfume
Perfume
Perfume is a mixture of fragrant essential oils and/or aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces "a pleasant scent"...

s are also components of modern detergents, provided that they are compatible with the other components and do not affect the colour of the cleaned item. The perfumes are typically a mixture of many compounds, a popular component being cyclohexyl salicylate, which is related to oil of wintergreen.

Environmental concerns


Early in the introduction of sulfonate-based detergents, concerns were voiced over the low rates of biodegradation
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

 of the branched alkylbenzenesulfonates. This problem was addressed by the introduction of linear alkylbenzenesulfonates.

A more profound problem arises from the heavy use of sodium triphosphate, which can comprise up to 50% by weight of detergents. The discharge of soluble phosphates into natural waters has led to problem with eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

 of lakes and streams. The replacement of sodium triphosphate by zeolite
Zeolite
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...

s offers some relief to this problem. With respect to the phosphate additives, between 1940 and 1970 "the amount of phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

s in city wastewater increased from 20,000 to 150,000 tons per year." With the increase in phosphates, algal bloom
Algal bloom
An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...

s grew splendidly on the excess phosphorus and consumed most of the oxygen in the waters, killing fish and plants.

In 2004, the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

 introduced regulations to require biodegradability in all detergents, and intends to ban phosphates in domestic products from 2013.

Australia began phasing out the use of phosphates in its detergents in 2011, with an all-out ban expected to take effect in 2014.

Pursuant to findings published in 2006 by the Shenkar College of Engineering and Design
Shenkar College of Engineering and Design
Shenkar College of Engineering and Design is a college in Ramat Gan, Israel. Shenkar serves the Israeli industry by providing academic qualification and R&D services for modern industries....

 indicating that liquid detergents are "much more environment-friendly" than powdered detergents, Israel's Ministry of the Environment began recommending that consumers prefer liquid detergent over powdered ones "for laundry which is not heavily stained."

External links

  • http://housewares.about.com/od/laundryappliances/f/hedetergents.htm
  • http://www.chemistry.co.nz/introduction.htm
  • http://www.laundryworks.ca//soap.com