Hair conditioner is a
hair care
Hair care is an overall term for hygiene and cosmetology involving the hair which grows from the human scalp, and to a lesser extent facial, pubic and other body hair. Hair care routines differ according to an individual's culture and the phy ...
cosmetic product used to improve the feel, texture, appearance, and manageability of
hair. Its main purpose is to reduce friction between strands of hair to allow smoother brushing or combing, which might otherwise cause damage to the scalp.
Various other benefits are often advertised, such as hair repair, strengthening, or a reduction in split ends.
Conditioners are available in a wide range of forms including viscous liquids, gels, and creams, as well as thinner lotions and sprays. Hair conditioner is usually used after the hair has been washed with
shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into th ...
. It is applied and worked into the hair, and may either be rinsed out a short time later or left in.
History
For centuries, natural oils have been used to condition human hair. A conditioner popular with men in the late
Victorian era
In the history of the United Kingdom and the British Empire, the Victorian era was the period of Queen Victoria's reign, from 20 June 1837 until her death on 22 January 1901. The era followed the Georgian period and preceded the Edward ...
was
Macassar oil, but this product was quite greasy and necessitated the pinning of a small cloth, known as an
antimacassar, to the headrests of chairs and sofas to preserve the upholstery from being damaged by the oil.
Modern hair conditioner was created at the turn of the 20th century when the
Edouard Pinaud company presented a product he called ''
Brilliantine'' at the
1900 Exposition Universelle in Paris. His product was intended to soften men's hair, including beards and moustaches. Since the invention of Pinaud's early products, modern science has advanced the hair conditioner industry to include those made with
silicone,
fatty alcohols, and
quaternary ammonium compounds. These chemical products have the benefits of hair conditioner without feeling greasy or heavy.
Mechanism of action
The outermost layer of a hair follicle is called the cuticle and is composed largely of
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ...
. This is rich in
cysteine
Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile.
When present as a deprotonated catalytic residue, s ...
groups which are mildly acidic. When the hair is washed these groups can
deprotonate, giving the hair a negative charge.
The ingredients in conditioner, especially positively charged
quaternary ammonium species, such as
behentrimonium chloride or polymers that are known as
Polyquaternium-XX, where XX is an arbitrary number, can then become attached to the hair via
electrostatic interactions. Once attached these compounds have several effects. Their long hydrocarbon backbone helps to lubricate the surface of each hair follicle, reducing the sensation of roughness and assisting combing. The surface coating of cationic groups means that hairs are repelled from each other electrostatically, which reduces clumping. The compounds can also act as
antistatic agents, which helps to reduce frizzing.
Types
* Conditioners, also called deep conditioners or hair masks, are heavy and thick, with a high content of
cationic surfactants that are able to bind to the hair structure and "glue" the hair surface scales together. This type of conditioner is designed to restore hair's moisture levels and reduce breakage. These are usually applied to the hair for a longer time (30-45 minutes).
* Leave-in conditioners are thinner and have different surfactants, which add only a little material to the hair to avoid weighing down the hair or causing greasiness. They are based on unsaturated fatty acid chains, which are bent, not straight. Leave-in conditioner is designed to be used in a similar way to hair oil, preventing the tangling of hair and keeping it smooth. Its use is particularly prevalent by those with naturally curly or kinky hair.
* Rinse out/Rinse through conditioners are the most common or generic on the market. Ordinary conditioners are generally applied directly after using shampoo, and manufacturers usually produce a conditioner counterpart for different types of shampoo for this purpose.
* Hold conditioners, based on
cationic
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
polyelectrolyte polymer
A polymer (; Greek ''poly-'', "many" + '' -mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and ...
s, hold the hair in a desired shape. These have a function and composition similar to diluted
hair gels.
* Cleansing conditioners are a newer category, typically based on a combination of
amphoteric
In chemistry, an amphoteric compound () is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used.
One type of amphoteric species are amphip ...
and
cationic
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
surfactants that can be used in place of a shampoo either as a pre-treatment before shampooing for hair that is damaged or very curly.
Ingredients
There are several types of hair conditioner ingredients, differing in composition and functionality:
*
Acidifiers,
acidity regulators which maintain the conditioner's
pH at about 3.5. In contact with
acidic
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a s ...
environment, the hair's somewhat scaly surface tightens up, as the
hydrogen bond
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing ...
s between the
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ...
molecules are strengthened.
*
Antistatic agents which bind to the hair and reduce the static, these can include cationic polymers such as Polyquaternium-10 and Guar Hydroxypropyltrimonium Chloride
* Detanglers, which modify the hair surface pH as acidifiers, or by coating it with
polymer
A polymer (; Greek ''poly-'', "many" + '' -mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and ...
s, as glossers.
* Glossers, light-reflecting chemicals which bind to the hair surface. Usually polymers, usually
silicones, e.g.,
Dimethicone or
Cyclopentasiloxane.
*
Lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
s, such as
fatty alcohols,
Panthenol,
Dimethicone, etc.
*
Moisturizer
A moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. The word "emollient" is derived from the Latin verb ''m ...
s, whose role is to hold moisture in the hair. Usually, these contain high proportions of
humectant
A humectant is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moisture ...
s. These could also be provided by natural oils such as Prunus Amygdalus Dulcis (Sweet Almond) Oil.
*
Oils (EFAs –
essential fatty acids
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them.
Only two fatty acids are known to be essential for humans: alpha-linolenic a ...
), which can help dry/porous hair become more soft and pliable. The scalp produces a natural oil called
sebum. EFAs are the closest thing to natural sebum (sebum contains EFAs).
*
Preservative
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or ...
s that protect the product from spoilage by microorganisms during the product shelf life.
* Reconstructors, usually containing
hydrolyzed protein. Their role is supposedly to penetrate the hair and strengthen its structure through polymer crosslinking.
*
Sequestrants, for better function in
hard water
Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, bicarbo ...
.
*
Sunscreen
Sunscreen, also known as sunblock or sun cream, is a photoprotective topical product for the skin that mainly absorbs, or to a much lesser extent reflects, some of the sun's ultraviolet (UV) radiation and thus helps protect against sunbu ...
, for protection against protein degradation and color loss. Currently Benzophenone-4 and Ethylhexyl Methoxycinnamate are the two sunscreens most commonly used in hair products. Cinnamidopyltrimonium Chloride and a few others are used to a much lesser degree. The common sunscreens used on skin are rarely used for hair products due to their texture and weight effects.
*
Surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, fo ...
s – approximately 97% of hair consists of a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
called
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ...
. The surface of keratin contains negatively charged
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...
s. Hair conditioners therefore usually contain cationic
surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, fo ...
s, which don't wash out completely, because their
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are ...
ends strongly bind to keratin. The
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, ...
ends of the surfactant molecules then act as the new hair surface.
Examples are Behentrimonium Chloride and Cetrimonium Chloride
* Thermal protectors, usually heat-absorbing polymers, shielding the hair against excessive heat, caused by, e.g.,
blow-drying,
curling irons or
hot rollers
Hot Rollers are an Australian band formed by Richie Lewis (Tumbleweed (band), Tumbleweed) and Mark "Kram (musician), Kram" Maher (Spiderbait). Their single "Wickerman Shoes" saw them nominated for ARIA Award for Breakthrough Artist – Single.
...
.
pH
Conditioners are frequently acidic, as
low pH protonates the
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ...
's amino acids. The hydrogen ions give the hair a positive charge and create more
hydrogen bond
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing ...
s among the keratin scales, giving the hair a more compact structure. Organic acids such as
citric acid
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in t ...
are usually used to maintain acidity.
See also
*
Anointing
Anointing is the ritual act of pouring aromatic oil over a person's head or entire body.
By extension, the term is also applied to related acts of sprinkling, dousing, or smearing a person or object with any perfumed oil, milk, butter, or o ...
*
Brilliantine
*
Brylcreem
*
Pomade
Pomade (; French ''pommade'') or pomatum is a greasy, waxy, or water-based substance that is used to style hair. Pomade generally gives the user's hair a shiny and slick appearance. It lasts longer than most hair-care products, and often re ...
*
Shampoo
Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into th ...
References
External links
How Hair Conditioner Worksat
h2g2
How to Apply Hair Conditionerat
wikiHow
{{DEFAULTSORT:Hair Conditioner
Hair care products