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 physic ...
cosmetic product used to improve the feel, texture, appearance, and manageability of
hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...
. 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 the ...
. 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 Edwardia ...
was
Macassar oil
Macassar oil is a compounded oil that was used primarily by Western European men throughout the 1800s and early 1900s as a hair conditioner to groom and style the hair.
It was popularised by Alexander Rowland (1747–1823), a celebrated London ba ...
, but this product was quite greasy and necessitated the pinning of a small cloth, known as an
antimacassar
An antimacassar is a small cloth placed over the backs or arms of chairs, or the head or cushions of a sofa, to prevent soiling of the permanent fabric underneath.Fleming, John & Hugh Honour. (1977) ''The Penguin Dictionary of Decorative Art ...
, 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
Brilliantine is a hair-grooming product intended to soften men's hair, including beards and moustaches, and give it a glossy, well-groomed appearance. It was created at the turn of the 20th century by French perfumer Édouard Pinaud (a.k.a. Ed. ...
'' 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
A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...
,
fatty alcohol
Fatty alcohols (or long-chain alcohols) are usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4–6 carbons to as many as 22–26, derived from natural fats and oils. The precise chain length varies ...
s, and
quaternary ammonium
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations ...
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, ho ...
. 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, sometime ...
groups which are mildly acidic. When the hair is washed these groups can
deprotonate
Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction.Henry Jakubowski, Biochemistry Online Chapter 2A3, https://employees.csbsju.ed ...
, giving the hair a negative charge.
The ingredients in conditioner, especially positively charged
quaternary ammonium
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations ...
species, such as
behentrimonium chloride
Behentrimonium chloride, also known as docosyltrimethylammonium chloride or BTAC-228, is a yellow waxlike organic compound with chemical formula , used as an antistatic agent and, sometimes, a disinfectant. It is commonly found in cosmetics su ...
or polymers that are known as
Polyquaternium
Polyquaternium is the International Nomenclature for Cosmetic Ingredients designation for several polycationic polymers that are used in the personal care industry. Polyquaternium is a neologism used to emphasize the presence of quaternary amm ...
-XX, where XX is an arbitrary number, can then become attached to the hair via
electrostatic interaction
Electrostatics is a branch of physics that studies electric charges at rest (static electricity).
Since classical times, it has been known that some materials, such as amber, attract lightweight particles after triboelectric effect, rubbing. ...
s. 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 agent
An antistatic agent is a compound used for treatment of materials or their surfaces in order to reduce or eliminate buildup of static electricity. Static charge may be generated by the triboelectric effect or by a non-contact process using a high ...
s, which helps to reduce frizzing.
Types
* Conditioners, also called deep conditioners or hair masks, are heavy and thick, with a high content of
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, foaming ...
s 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 convent ...
polyelectrolyte
Polyelectrolytes are polymers whose repeating units bear an electrolyte group. Ion#Anions and cations, Polycations and polyanions are polyelectrolytes. These groups dissociation (chemistry), dissociate in aqueous solutions (water), making the pol ...
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 a ...
s, hold the hair in a desired shape. These have a function and composition similar to diluted
hair gel
Hair gel is a hairstyling product that is used to harden hair into a particular hairstyle.
History
Analysis of ancient Egyptian mummies has shown that they styled their hair using a fat-based gel. The researchers behind the analysis say that t ...
s.
* 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 amphiproti ...
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 convent ...
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:
*
Acidifier
Acidifiers are inorganic chemicals that, put into a human (or other mammalian) body, either produce or become acid.
These chemicals increase the level of gastric acid in the stomach
The stomach is a muscular, hollow organ in the gastroin ...
s,
acidity regulator
Acidity regulators, or pH control agents, are food additives used to change or maintain pH (acidity or basicity). They can be organic or mineral acids, bases, neutralizing agents, or buffering agents. Typical agents include the following acids ...
s 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 sequ ...
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 a ...
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, ho ...
molecules are strengthened.
*
Antistatic agent
An antistatic agent is a compound used for treatment of materials or their surfaces in order to reduce or eliminate buildup of static electricity. Static charge may be generated by the triboelectric effect or by a non-contact process using a high ...
s 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 a ...
s, as glossers.
* Glossers, light-reflecting chemicals which bind to the hair surface. Usually polymers, usually
silicone
A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...
s, e.g.,
Dimethicone
Polydimethylsiloxane (PDMS), also known as dimethylpolysiloxane or dimethicone, belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, as i ...
or
Cyclopentasiloxane
Decamethylcyclopentasiloxane, also known as D5 and D5, is an organosilicon compound with the formula . It is a colorless and odorless liquid that is slightly Volatility (chemistry), volatile.
Use
The compound is classified as a cyclomethicone. ...
.
*
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 alcohol
Fatty alcohols (or long-chain alcohols) are usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4–6 carbons to as many as 22–26, derived from natural fats and oils. The precise chain length varies ...
s,
Panthenol
Panthenol (also called pantothenol) is the alcohol analog of pantothenic acid (vitamin B5), and is thus a provitamin of B5. In organisms, it is quickly oxidized to pantothenic acid. It is a viscous transparent liquid at room temperature. Pantheno ...
,
Dimethicone
Polydimethylsiloxane (PDMS), also known as dimethylpolysiloxane or dimethicone, belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, as i ...
, 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
humectants. These could also be provided by natural oils such as Prunus Amygdalus Dulcis (Sweet Almond) Oil.
*
Oil
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...
s (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 ac ...
), which can help dry/porous hair become more soft and pliable. The scalp produces a natural oil called
sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...
. 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 by ...
s that protect the product from spoilage by microorganisms during the product shelf life.
* Reconstructors, usually containing
hydrolyzed protein
Hydrolyzed protein is a solution derived from the hydrolysis of a protein into its component amino acids and peptides. While many means of achieving this exist, most common is prolonged heating with hydrochloric acid, sometimes with an enzyme su ...
. Their role is supposedly to penetrate the hair and strengthen its structure through polymer crosslinking.
*
Sequestrant
A sequestrant is a food additive which improves the quality and stability of foods. A sequestrant forms chelate complexes with polyvalent metal ions, especially copper, iron and nickel, which can prevent the oxidation of the fats in the food. Se ...
s, 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 sunburn and ...
, 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, foaming ...
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, respo ...
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, ho ...
. 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 am ...
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, foaming ...
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 no ...
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, th ...
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 iron
A hair iron or hair tong is a tool used to change the arrangement of the hair using heat. There are three general kinds: ''curling irons'', used to make the hair curly, ''straightening irons'', commonly called ''straighteners'' or ''flat irons'', ...
s or
hot rollers.
pH
Conditioners are frequently acidic, as
low pH protonate
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), (H+) to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, ...
s 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, ho ...
'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 a ...
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 oth ...
*
Brilliantine
Brilliantine is a hair-grooming product intended to soften men's hair, including beards and moustaches, and give it a glossy, well-groomed appearance. It was created at the turn of the 20th century by French perfumer Édouard Pinaud (a.k.a. Ed. ...
*
Brylcreem
__NOTOC__
Brylcreem () is a British brand of hair styling products for men. The first Brylcreem product was a hair cream created in 1928 by County Chemicals at the Chemico Works in Bradford Street, Birmingham, England, and is the flagship produ ...
*
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 the ...
References
External links
How Hair Conditioner Worksat
h2g2
The h2g2 website is a British-based collaborative online encyclopedia project. It describes itself as "an unconventional guide to life, the universe, and everything", in the spirit of the fictional publication '' The Hitchhiker's Guide to ...
How to Apply Hair Conditionerat
wikiHow
wikiHow is an online wiki-style publication featuring how-to articles on a variety of topics. Founded in 2005 by Internet entrepreneur Jack Herrick, its aim is to create an extensive database of instructional content, using the wiki model of ope ...
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Hair care products