From en.wikipedia.org:
[Surfactants with cleansing properties] [other uses] [date=November 2018] A
DETERGENT is a formulated and commercially sold product for cleaning that
contains surfactants plus other components.[1] Detergents comprise surfactants
as main functional components to remove hydrophobic grease or dirt by
dispersing them in water. They often further comprise water (to facilitate
application), builders (to soften water), enzymes (for breaking down proteins,
fats, or starches), and dyes or fragrances (to improve the user's sensory
experience).
Common surfactants used in detergents are alkylbenzene sulfonates, which are
soap-like compounds that are more soluble than soap in hard water, because the
polar sulfonate is less likely than the polar carboxylate of soap to bind to
calcium and other ions found in hard water.
** Definitions
The word _detergent_ is derived from the Latin adjective [la], from the verb
[la], meaning to wipe or polish off. Detergent can be defined as a surfactant
or a mixture of surfactants with cleansing properties when in dilute
solutions.<ref name=":0"/> However, conventionally, detergent is used to mean
synthetic cleaning compounds as opposed to _soap_ (a salt of the natural fatty
acid), even though soap is also a detergent in the true sense.[2] In domestic
contexts, the term _detergent_ refers to household cleaning products such as
_laundry detergent_ or _dish detergent_, which are in fact complex mixtures of
different compounds, not all of which are by themselves detergents.
Detergency is the ability to remove unwanted substances termed 'soils' from a
substrate (e.g., clothing).[3]
** Components
Detergents are formulated products used for cleaning, i. e. mixtures of
various chemical components that are selected and mixed to achieve a good
cleaning performance and applicants satisfaction. Detergents comprise
surfactants or a surfactant as main functional component, aside usually water
and auxiliary materials (builders, enzymes, etc.).
*** Surfactants
[Surfactant] Surfactants are a group of compounds with an amphiphilic
structure, where each molecule has a hydrophilic (polar) head and a long
hydrophobic (non-polar) tail. The hydrophobic portion of these molecules may
be straight- or branched-chain hydrocarbons, or it may have a steroid
structure. The hydrophilic portion is more varied, they may be ionic or
non-ionic, and can range from a simple to a relatively elaborate structure.[4]
Surfactants are called so since they can decrease the surface tension of
water. Their dual nature facilitates the mixture of hydrophobic compounds
(like oil and grease) with water. Because air is not hydrophilic, surfactants
are also foaming agents to varying degrees.
Surfactant molecules aggregate to form micelles, which makes them soluble in
water. The hydrophobic group of the surfactant is the main driving force of
micelle formation, its aggregation forms the hydrophobic core of the micelles.
The micelle can remove grease, protein or soiling particles. The
concentration at which micelles start to form is the critical micelle
concentration (CMC), and the temperature at which the micelles further
aggregate to separate the solution into two phases is the cloud point when the
solution becomes cloudy and detergency is optimal.<ref name="neugebauer" />
Many detergents work better in an alkaline pH. The properties of detergents
are dependent on the molecular structure of the monomer. The ability to foam
may be determined by the head group, for example anionic surfactants are
high-foaming, while nonionic surfactants may be non-foaming or low-foaming.[5]
**** Chemical classifications of surfactants
Surfactants are classified into four broad groupings, depending on the
electrical charge of the surfactants.[6]
***** Anionic surfactants
Typical anionic surfactants are alkylbenzene sulfonates. 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.[7]
Anionic surfactants are the most common form of surfactants, and an estimated
6 billion kilograms of anionic surfactants are produced annually for the
domestic markets.
Bile acids, such as deoxycholic acid (DOC), are anionic surfactants produced
by the liver to aid in digestion and absorption of fats and oils.
***** Cationic surfactants
Cationic surfactants are similar to anionic ones, but quaternary ammonium
replaces the hydrophilic anionic sulfonate group. The ammonium sulfate center
is positively charged.<ref name="Ullmann" /> Cationic surfactants generally
have poor detergency.
***** Non-ionic surfactants
Non-ionic surfactants are characterized by their uncharged, hydrophilic
headgroups. Typical non-ionic surfactants 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 and their
metabolites, nonylphenol. Glycosides have a sugar as their uncharged
hydrophilic headgroup. Examples include octyl thioglucoside and maltosides.
HEGA and MEGA series surfactants are similar, possessing a sugar alcohol as
headgroup.
***** Amphoteric surfactants
[Surfactant#Applications and sources]
Amphoteric or zwitterionic surfactants have zwitterions within a particular pH
range, and possess a net zero charge arising from the presence of equal
numbers of +1 and −1 charged chemical groups. Examples include CHAPS.
** History
[Soap#History]
Soap is known to have been used as a surfactant for washing clothes since the
Sumerian time in 2,500 B.C.<ref name=falbe2>[editor=Jürgen Falbe ] In ancient
Egypt, soda was used as a wash additive. In the 19th century, synthetic
surfactants began to be created, for example from olive oil.<ref name="sosis
5"/> Sodium silicate (water glass) was used in soap-making in the United
States in the 1860s,[8] and in 1876, Henkel sold a sodium silicate-based
product that can be used with soap and marketed as a "universal detergent"
(_Universalwaschmittel_) in Germany. Soda was then mixed with sodium silicate
to produce Germany's first brand name detergent Bleichsoda.[9] In 1907, Henkel
also added a bleaching agent sodium perborate to launch the first
'self-acting' laundry detergent Persil to eliminate the laborious rubbing of
laundry by hand.[10]
During the First World War, there was a shortage of oils and fats needed to
make soap. In order to find alternatives for soap, synthetic detergents were
made in Germany by chemists using raw material derived from coal
tar.[11][12][13] These early products, however, did not provide sufficient
detergency. In 1928, effective detergent was made through the sulfation of
fatty alcohol, but large-scale production was not feasible until low-cost
fatty alcohols become available in the early 1930s.<ref name=falbe /> The
synthetic detergent created was more effective and less likely to form scum
than soap in hard water, and can also eliminate acid and alkaline reactions
and decompose dirt. Commercial detergent products with fatty alcohol
sulphates began to be sold, initially in 1932 in Germany by Henkel.<ref
name=falbe /> In the United States, detergents were sold in 1933 by Procter &
Gamble (Dreft) primarily in areas with hard water.<ref
name="WhittenWhitten1997"/> However, sales in the US grew slowly until the
introduction of 'built' detergents with the addition of effective phosphate
builder developed in the early 1940s.<ref name="WhittenWhitten1997"/> The
builder improves the performance of the surfactants by softening the water
through the chelation of calcium and magnesium ions, helping to maintain an
alkaline pH, as well as dispersing and keeping the soiling particles in
solution.[14] The development of the petrochemical industry after the Second
World War also yielded material for the production of a range of synthetic
surfactants, and alkylbenzene sulfonates became the most important detergent
surfactants used.<ref name=handbook>[url= [dXn3aB1DKk4C]] By the 1950s,
laundry detergents had become widespread, and largely replaced soap for
cleaning clothes in developed countries.<ref name=falbe>[editor=Jürgen Falbe ]
Over the years, many types of detergents have been developed for a variety of
purposes, for example, low-sudsing detergents for use in front-loading washing
machines, heavy-duty detergents effective in removing grease and dirt,
all-purpose detergents and specialty detergents.<ref
name="WhittenWhitten1997"/>[15] They become incorporated in various products
outside of laundry use, for example in dishwasher detergents, shampoo,
toothpaste, industrial cleaners, and in lubricants and fuels to reduce or
prevent the formation of sludge or deposits.[16] The formulation of detergent
products may include bleach, fragrances, dyes and other additives. The use of
phosphates in detergent, however, led to concerns over nutrient pollution and
demand for changes to the formulation of the detergents.[17] Concerns were
also raised over the use of surfactants such as branched alkylbenzene
sulfonate (tetrapropylenebenzene sulfonate) that lingers in the environment,
which led to their replacement by surfactants that are more biodegradable,
such as linear alkylbenzene sulfonate.<ref name=falbe /><ref name=handbook />
Developments over the years have included the use of enzymes, substitutes for
phosphates such as zeolite A and NTA, TAED as bleach activator, sugar-based
surfactants which are biodegradable and milder to skin, and other green
friendly products, as well as changes to the form of delivery such as tablets,
gels and pods.<ref name=Middelhauve>[url= [VMqSJROG_WYC]][18]
** Major applications of detergents
*** Household cleaning
[Laundry detergent]
One of the largest applications of detergents is for household and shop
cleaning including dish washing and washing laundry. These detergents are
commonly available as powders or concentrated solutions, and the formulations
of these detergents are often complex mixtures of a variety of chemicals aside
from surfactants, reflecting the diverse demands of the application and the
highly competitive consumer market. These detergents may contain the
following components:<ref name=Middelhauve />
- surfactant s
- foam regulator s
- builders
- bleach
- bleach activator s
- enzyme s
- dyes
- fragrances
- other additives
*** Fuel additives
Both carburetors and fuel injector components of internal combustion 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.[19]
*** Biological reagent
Reagent grade detergents are employed for the isolation and purification of
integral membrane proteins found in biological cells.[20] Solubilization of
cell membrane bilayers requires a detergent that can enter the inner membrane
monolayer.[21] Advancements in the purity and sophistication of detergents
have facilitated structural and biophysical characterization of important
membrane proteins such as ion channels also the disrupt membrane by binding
lipopolysaccharide,[22] transporters, signaling receptors, and photosystem
II.[23]
** See also
- Cleavable detergent
- Dishwashing liquid
- Dispersant
- Green cleaning
- Hard-surface cleaner
- Laundry detergent
- List of cleaning products
- Triton X-100
** References
[reflist]
** External links
[detergent] [Detergents]
- About.com: How Do Detergents Clean (see http://chemistry.about.com/od/howthingswork/f/detergentfaq.htm) [url=https://web.archive.org/web/20110106021626/http://chemistry.about.com/od/howthingswork/f/detergentfaq.htm ]
- Campbell tips (see https://web.archive.org/web/20161119130839/http://www.chemistry.co.nz/deterginfo.htm) for detergents chemistry, surfactants (see https://web.archive.org/web/20161129064828/http://www.chemistry.co.nz/surfactants.htm) , and history (see https://web.archive.org/web/20161017172455/http://www.chemistry.co.nz/deterghistory.htm) related to laundry washing, destaining methods (see https://web.archive.org/web/20161129092315/http://www.chemistry.co.nz/stain_frame.htm) and soil (see https://web.archive.org/web/20161018085331/http://www.chemistry.co.nz/soil_id.htm) .
- [1= Formulation of Detergent (see https://web.archive.org/web/20210519103618/https://laundrydetergentideas.com/formulation-of-detergent/) ]
[Authority control]
Category:Cleaning products Category:Membrane-active molecules
Category:Surfactants