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Reactive Dye
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with the substrate. Reactive dyes have good fastness properties owing to the covalent bonding that occurs during dyeing. Reactive dyeing is the most important method for coloring cellulose fibers. Reactive dyes can also be applied on wool and nylon; in the latter case they are applied under weakly acidic conditions. Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group also bonds to water, creating hydrolysis.Horst Tappe, Walter Helmling, Peter Mischke, Karl Rebsamen, Uwe Reiher, Werner Russ, Ludwig Schläfer and Petra Vermehren "Reactive Dyes"in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. Usage Reactive dyes had been tested in the late 1800s involving both adding functionalized dyes to the substrate and then activating the substrate first followed by fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromophore
A chromophore is the part of a molecule responsible for its color. The color that is seen by our eyes is the one not absorbed by the reflecting object within a certain wavelength spectrum of visible light. The chromophore is a region in the molecule where the energy difference between two separate molecular orbitals falls within the range of the visible spectrum. Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change in the molecule when hit by light. Conjugated pi-bond system chromophores Just like how two adjacent p-orbitals in a molecule will form a pi-bond, three or more adjacent p-orbitals in a molecule can form a conjugated pi-system. In a conjugated pi-system, electrons are able to capture certain photons as the electrons resonate along a certain distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactive Dyes
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with the substrate. Reactive dyes have good fastness properties owing to the covalent bonding that occurs during dyeing. Reactive dyeing is the most important method for coloring cellulose fibers. Reactive dyes can also be applied on wool and nylon; in the latter case they are applied under weakly acidic conditions. Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group also bonds to water, creating hydrolysis.Horst Tappe, Walter Helmling, Peter Mischke, Karl Rebsamen, Uwe Reiher, Werner Russ, Ludwig Schläfer and Petra Vermehren "Reactive Dyes"in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. Usage Reactive dyes had been tested in the late 1800s involving both adding functionalized dyes to the substrate and then activating the substrate first followed by fixa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyeing
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fiber by absorption, diffusion, or bonding with temperature and time being key controlling factors. The bond between dye molecule and fiber may be strong or weak, depending on the dye used. Dyeing and printing are different applications; in printing, color is applied to a localized area with desired patterns. In dyeing, it is applied to the entire textile. The primary source of dye, historically, has been nature, with the dyes being extracted from animals or plants. Since the mid-19th century, however, humans have produced artificial dyes to achieve a broader range of colors and to render the dyes more stable to washing and general use. Different classes of dyes are used for different types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cationization Of Cotton
Cationization of cotton is an electro kinetic phenomena ( zeta potential and electro kinetic) for surface charge of cotton. The cotton surface is charged with positive ions. Cationization alters the characterization of the surface of the cotton which allows salt free dyeing and improves the dye ability of cotton. The process involves the chemical reaction of cationic reactive agents with cellulose. Etymology A cation (+) (/ˈkætˌaɪ.ən/), from the Greek word κάτω (káto), meaning "down", is an ion with fewer electrons than protons, giving it a positive charge. The suffixes for cationic groups discern between 'ylium' for cations created by the loss of a hydride ion and 'ium' for cations formed by addition of a Hydron. Methods of cationization Cationization involves the modification of cellulosic macromolecules with positively charged sites with chemical reaction of cationic reactive agents for example with Quaternary ammonium cation or using (3-chloro-2-hydroxylpropyl) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbene Dye
A carbene dye is a reactive dye based on carbene chemistry. A benzophenone is functionalised with a chromophore or group that can be easily converted to a chromophore at a later stage. The functionalised benzophenone is reacted with hydrazine hydrate and subsequently treatment with mercury oxide. The resulting diazo compound is stable at room temperature. On heating, nitrogen gas is released and the carbene generated. The thus generated carbene reacts rapidly with substrates such as nylon, cotton, glass and polyethylene. The highly reactive carbene group removes the need for different functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the re ...s depending on the substrate to be dyed. For example, a dye that can colour cotton would usually not be appropriate for dyeing po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanimine
Ethanimine is an organonitrogen compound classified as an imine. It is formed by reacting acetaldehyde and ammonia, but rapidly polymerizes to acetaldehyde ammonia trimer. It has two tautomers: ethanimine, an imine, and ethenamine or aminoethylene, an amine. Ethanimine has two hydrogens on the carbon, while ethenamine has two on the nitrogen atom. Occurrence It is not well known terrestrially, but has been detected in abundance toward Sagittarius B2 (Sgr B2), a dense interstellar cloud between stars toward the galactic center of the Milky Way. The distance between the Sgr B2 cloud and center of galaxy is 100 pc (1 pc = 3.26 ly). Ethanimine is mainly found in hot cores of ISM clouds; in case of Sgr B2, the region would be the Sgr B2 N and Sgr B2 M. Radio telescopes such as the Green Bank Observatory's Green Bank Telescope The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinyl Sulfone Dyes
Vinyl sulfone dyes are reactive dyes comprising a vinyl sulfone group as reactive group (a fiber-bonding site of the reactive dye, "reactive hook"). Due to the relatively high reactivity of the vinyl sulfone group with water (residual moisture, air humidity), it is present in many commercial products in a protected form. For protection, an ethylsulfonyl group is substituted with a leaving group. During the dyeing process under alkaline conditions, the vinyl sulfone group is released by an elimination reaction: Formation of the vinyl sulfone group by alkaline elimination. R= alkyl or aryl radical, X=-OSO3H, -Cl Chemical structure The vinyl sulfone reactive anchor is usually introduced into the reactive dye via an aromatic or aliphatic amine. The oldest and most common intermediate is vinyl sulfone parabase ester (see image), an aniline substituted with a -(sulfooxy)ethylulfonyl group. The vinyl sulfone parabase ester can be used as a diazo component in the preparation of azo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinoxaline
A quinoxaline, also called a benzopyrazine, in organic chemistry, is a heterocyclic compound containing a ring complex made up of a benzene ring and a pyrazine ring. It is isomeric with other naphthyridines including quinazoline, phthalazine and cinnoline. It is a colorless oil that melts just above room temperature. Although quinoxaline itself is mainly of academic interest, quinoxaline derivatives are used as dyes, pharmaceuticals (such as varenicline), and antibiotics such as olaquindox, carbadox, echinomycin, levomycin and actinoleutin. Synthesis They can be formed by condensing ''ortho''-diamines with 1,2-diketones. The parent substance of the group, quinoxaline, results when glyoxal is condensed with 1,2-diaminobenzene. Substituted derivatives arise when α-ketonic acids, α-chlorketones, α-aldehyde alcohols and α-ketone alcohols are used in place of diketones. Quinoxaline and its analogues may also be formed by reduction of amino acids substituted 1,5-difluoro-2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrimidine
Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other diazines are pyrazine (nitrogen atoms at the 1 and 4 positions) and pyridazine (nitrogen atoms at the 1 and 2 positions). In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U). Occurrence and history The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives, including the nucleotides cytosine, thymine and uracil, thiamine (vitamin B1) and alloxan. It is also found in many synthetic compounds such as barbiturates and the HIV drug, zidovudine. Although pyrimidine derivatives such as alloxan were known in the early 19th century, a laboratory synthesis of a pyrimidine was not carried out until 1879, when Grimaux reported the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Procion
Procion is a brand of fibre reactive dyes. They are commonly used in tie dye and other textile crafts. They are dichlorotriazine dyes and were originally made by Imperial Chemical Industries. The brand name is now owned by Dystar, but, since the patent on the dyes has expired, many manufacturers around the world now make them.Horst Tappe, Walter Helmling, Peter Mischke, Karl Rebsamen, Uwe Reiher, Werner Russ, Ludwig Schläfer and Petra Vermehren "Reactive Dyes"in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. Procion dyes *Procion MX are a class of cold reactive dyes. *Procion H-E and H-EXL are hot water dyes *Procion P and SP are designed for textile printing Textile printing is the process of applying color to fabric in definite patterns or designs. In properly printed fabrics the colour is bonded with the fibre, so as to resist washing and friction. Textile printing is related to dyeing but in ... References External links *Procion MX ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triazine
Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is . They exist in three isomeric forms, 1,3,5-triazines being common. Structure The triazines have planar six-membered benzene-like ring but with three carbons replaced by nitrogens. The three isomers of triazine are distinguished by the positions of their nitrogen atoms, and are referred to as 1,2,3-triazine, 1,2,4-triazine, and 1,3,5-triazine. Other aromatic nitrogen heterocycles are pyridines with one ring nitrogen atom, diazines with 2 nitrogen atoms in the ring, triazoles with 3 nitrogens in a 5 membered ring, and tetrazines with 4 ring nitrogen atoms. Uses Melamine A well known triazine is melamine (2,4,6-triamino-1,3,5-triazine). With three amino substituents, melamine is a precursor to commercial resins. Guanamines are closely related to melamine, except with one amino substituent replaced by an organic group. This difference is exploited in the use of guanamines t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaline
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English language, English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the acid-base reaction theories#Arrhenius theory, Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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