|
Relaxer
A relaxer is a type of lotion or cream generally used by people with tight curls or very curly hair which makes hair easier to hair straightening, straighten by chemically "relaxing" the natural curls. The active agent is usually a strong alkali, although some formulations are based on ammonium thioglycolate or formaldehyde. History The first documented history of the relaxer began with Garrett Augustus Morgan in 1909. His hair straighten cream was found accidentally when trying to find a solution to ease friction on sewing machines in his tailor shop. Morgan tested his cream on a neighboring dog's fur. With the success of the cream, he established G.A. Morgan Hair Refining Company and began selling his product to Black/mixed people. General usage Hair relaxing, or lanthionization, colloquially known as a perm, can be performed by a professional cosmetologist in a salon, a professional barber in a barbershop or at home with relaxer kits. As with hair dye, the treated portion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Hair Naturalizer System
The Rio Hair Naturalizer System was a hair relaxer distributed by the World Rio Corporation Inc. It was available in two types; "Neutral", and one that claimed to have a "Color Enhancement Formula" that contained a black hair dye. As a product designed for home use, it was promoted through infomercials in the early to mid-1990s. The U.S. Food and Drug Administration (FDA) and state government offices began receiving complaints about the Rio hair products in mid-1994. Many complainants said they had bought the hair relaxers by mail after viewing a 30-minute TV infomercial targeted to African Americans. Some complainants reported that their hair began falling out immediately after applying the products, while others said they had problems after multiple applications. Some said they had seen doctors for treatment of scalp irritation. Many women said they had to cut their hair short to deal with bald spots. Timeline November 6 and 8, 1994 FDA collected samples of the hair relaxers, at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hair Straightening
Hair straightening is a hair styling technique used since the 1890s involving the flattening and straightening of hair in order to give it a smooth, streamlined, and sleek appearance. It became very popular during the 1950s among black males and females of all races. It is accomplished using a hair iron or hot comb, chemical relaxers, Japanese hair straightening, Brazilian hair straightening, or roller set/ blowdryer styling. In addition, some shampoos, conditioners, and hair gels can help to make hair temporarily straight. The process is often called "rebonding" in some countries from Southeast Asia (e.g. Indonesia, Singapore, Malaysia and Philippines). If done often, flat irons and chemicals can be damaging to hair. Excessive straightening often results in split ends. However, heat protectant sprays can decrease the damage. Methods Temporary (non-chemical treatment) Hair irons and hot combs are designed to temporarily modify the shape/texture of hair. The straightened ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates . The monohydrate crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide" is often this monohydrate, and published data may refer to it instead of the anhydrous compound. As one of the simplest hydroxides, sodium hydroxide is frequently used alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students. Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perm (hairstyle)
A permanent wave, commonly called a perm or permanent (sometimes called a "curly perm" to distinguish it from a " straight perm"), is a hairstyle consisting of waves or curls set into the hair. The curls may last a number of months, hence the name. Perms may be applied using thermal or chemical means. In the latter method, chemicals are applied to the hair, which is then wrapped around forms to produce waves and curls. The same process is used for chemical straightening or relaxing, with the hair being flattened instead of curled during the chemical reaction. History The first person to produce a practical thermal method was Marcel Grateau in 1872. He devised a pair of specially manufactured tongs, in which one of the arms had a circular cross-section and the other a concave one, so that one fitted inside the other when the tongs were closed. The tongs were generally heated over a gas or alcohol flame and the correct temperature was achieved by testing the tongs on a newspaper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmetologist
Cosmetology (from Greek , ''kosmētikos'', "beautifying"; and , ''-logia'') is the study and application of beauty treatment. Branches of specialty include hairstyling, skin care, cosmetics, manicures/pedicures, non-permanent hair removal such as waxing and sugaring, and permanent hair removal processes such as electrology and intense pulsed light (IPL). In the United States as of 2018, an occupational license is required in all states to be a cosmetologist, with the average cost of a certificate from a for-profit school being $17,000 and 1,500 required hours, (ten times the hours required for an EMT), with cosmetologists making a median wage of $25,000. Cosmetology specialties Cosmetologist Cosmetologists are trained and licensed to perform cosmetic treatments to the hair, skin, and nails. This can be expanded into multiple parts including cutting and chemically treating hair, chemical hair removal, fashion trends, wigs, nails and skin care, skin and hair analysis; relaxa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanidine
Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine predominantly in patients experiencing renal failure. A guanidine moiety also appears in larger organic molecules, including on the side chain of arginine. Structure Guanidine can be thought of as a nitrogenous analogue of carbonic acid. That is, the C=O group in carbonic acid is replaced by a C=NH group, and each OH is replaced by a group. Isobutene can be seen as the carbon analogue in much the same way. A detailed crystallographic analysis of guanidine was elucidated 148 years after its first synthesis, despite the simplicity of the molecule. In 2013, the positions of the hydrogen atoms and their displacement parameters were accurately determined using single-crystal neutron diffraction. Production Guanidine can be obtained from natural sources, being first isolat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Hydroxide
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime (calcium oxide) is mixed or slaked with water. It has many names including hydrated lime, caustic lime, builders' lime, slaked lime, cal, and pickling lime. Calcium hydroxide is used in many applications, including food preparation, where it has been identified as E number E526. Limewater, also called milk of lime, is the common name for a saturated solution of calcium hydroxide. Properties Calcium hydroxide is poorly soluble in water, with a retrograde solubility increasing from 0.66 g/L at 100 °C to 1.89 g/L at 0 °C. With a solubility product ''K''sp of 5.02 at 25 °C, its dissociation in water is large enough that its solutions are basic according to the following dissolution reaction: : Ca(OH)2 → Ca2+ + 2 OH− At ambient temperature, calcium hydroxide (portlandite) d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perm Salt
Ammonium thioglycolate, also known as perm salt, is the salt of thioglycolic acid and ammonia. It has the formula HSCH2CO2NH4 and has use in perming hair. Chemistry Being the salt of a weak acid and weak base, ammonium thioglycolate exists in solution as an equilibrium mixture of the salt itself as well as thioglycolic acid and ammonia: :HSCH2COO− + NH4+ ⇌ HSCH2COOH + NH3 Thioglycolate, in turn, is able to cleave disulfide bonds, capping one side with a hydrogen and forming a new disulfide with the other side: :RSH + R'SSR' ⇌ R'SH + RSSR' Use in Perms A solution containing ammonium thioglycolate contains a lot of free ammonia, which swells hair, rendering it permeable. The thioglycolic acid in the perm solution reduces the disulfide cystine bonds in the cortex of the hair. In a sense, the thioglycolate removes crosslinks. After washing, the hair is treated with a mild solution of hydrogen peroxide, which oxidizes the cysteines back to cystine. Thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reducing Agent
In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ). Examples of substances that are commonly reducing agents include the Earth metals, formic acid, oxalic acid, and sulfite compounds. In their pre-reaction states, reducers have extra electrons (that is, they are by themselves reduced) and oxidizers lack electrons (that is, they are by themselves oxidized). This is commonly expressed in terms of their oxidation states. An agent's oxidation state describes its degree of loss of electrons, where the higher the oxidation state then the fewer electrons it has. So initially, prior to the reaction, a reducing agent is typically in one of its lower possible oxidation states; its oxidation state increases during the reaction while that of the oxidizer decreases. Thus in a redox reaction, the agent whose oxidation state increases, that "loses/ donates electrons", that "i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotion
Lotion is a low-viscosity topical preparation intended for application to the skin. By contrast, creams and gels have higher viscosity, typically due to lower water content. Lotions are applied to external skin with bare hands, a brush, a clean cloth, or cotton wool. While a lotion may be used as a medicine delivery system, many lotions, especially hand lotions and body lotions and lotion for allergies are meant instead to simply smooth, moisturize, soften and, sometimes, perfume the skin. Some skincare products, such as sunscreen and moisturizer, may be available in multiple formats, such as lotions, gels, creams, or sprays. Medicine delivery Dermatologists can prescribe lotions to treat or prevent skin diseases. It is not unusual for the same drug ingredient to be formulated into a lotion, cream and ointment. Creams are the most convenient of the three but inappropriate for application to regions of hairy skin such as the scalp, while a lotion is less viscous and may be r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystine
Cystine is the oxidized derivative of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that is poorly soluble in water. As a residue in proteins, cystine serves two functions: a site of redox reactions and a mechanical linkage that allows proteins to retain their three-dimensional structure. Formation and reactions Structure Cystine is the disulfide derived from the amino acid cysteine. The conversion can be viewed as an oxidation: : Cystine contains a disulfide bond, two amine groups, and two carboxylic acid groups. As for other amino acids, the amine and carboxylic acid groups exist is rapid equilibrium with the ammonium-carboxylate tautomer. The great majority of the literature concerns the ''l,l-''cystine, derived from ''l''-cysteine. Other isomers include ''d,d''-cystine and the meso isomer d,l-cystine, neither of which is biologically significant. Occurrence Cystine is common in many foods such as eggs, meat, dairy products, and whole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
