dye


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Idioms, Wikipedia.

dye

dye, any substance, natural or synthetic, used to color various materials, especially textiles, leather, and food. Natural dyes are so called because they are obtained from plants (e.g., alizarin, catechu, indigo, and logwood), from animals (e.g., cochineal, kermes, and Tyrian purple), and from certain naturally occurring minerals (e.g., ocher and Prussian blue). They have been almost entirely replaced in modern dyeing by synthetic dyes. Most of these have been prepared from coal tar or petroleum, being formed from an aromatic hydrocarbon such as benzene, from which indigo is derived (see also aniline), or anthracene, which yields alizarin.

Although some materials, e.g., silk and wool, can be colored simply by being dipped in the dye (the dyes so used are consequently called direct dyes), others, including cotton, commonly require the use of a mordant (see also lake). Alizarin is a mordant dye and the color it gives depends upon the mordant used. Dyes are classified also as acidic or basic according to the medium required in the dyeing process. A vat dye, e.g., indigo, is so called from the method of its application; it is first treated chemically so that it becomes soluble and is then used for coloring materials bathed in a vat.

When the materials become impregnated with the dye, they are removed and dried in air, the indigo reverting to its original, insoluble form. The process by which a dye becomes “attached” to the material it colors is not definitely known. One theory holds that a chemical reaction takes place between the dye and the treated fiber; another proposes that the dye is absorbed by the fiber.

Dyeing is an ancient industry. The ancient Peruvians, Chinese, Indians, Persians, Phoenicians, and others used natural dyes many centuries ago, including indigo, one of the oldest dyes in use, and Tyrian purple, derived from several species of sea snail. The Egyptians prepared some brilliant colors. In the 13th and 14th cent. dyeing assumed importance in Italy; the methods employed were carried to other parts of Europe and, as new dyes became known, the dyeing industry flourished and grew. Cochineal was introduced from Mexico. Finally, in the 19th cent. the work of W. H. Perkin and Adolf von Baeyer produced the first synthetic dyes.

Bibliography

See S. Robinson, The History of Dyed Textiles (1970); H. Zollinger, Color Chemistry: Syntheses, Properties, and Applications of Organic Dyes and Pigments (1987); D. R. Waring and G. Hallas, ed., The Chemistry and Application of Dyes (1989).

The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.

dye

[]
(chemistry)
A colored substance which imparts more or less permanent color to other materials. Also known as dyestuff.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

dye

A coloring material or compound that imparts color throughout a material by penetration.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
The percentage of dye bath exhaustion (% E) by the wool fabric under the conditions specified in the experimental section was also calculated.
Agricultural dyes are the specific category of colourants which are used in fertilizers, and seeds.
In order to study the effect of initial dye concentration on dye decolorization potential and tolerance of the strain ts17, the isolate was cultivated for more than 4 days and was amended with different concentrations (50-2000mg/L) of Amaranth at concentration gradient 50mg/L.
Next, add the dissolved dye to the dye pot of water.
The amount of 1g of Red-FB disperse dye (Hangzhou Emperor Chemical Co., Ltd.) was included with 99 mL of boiling water.
The previously isolated two potential isolates of Streptomyces DJP15 and Streptomyces DJP27 were assessed in combination for effective degradation of azo blue dye. Effect of inoculum size in different combinations was mainly focused for effective dye degradation, as per the method of Senan and Abraham (2004) and Khadijah et al., (2009).
For dye N719, the absorbance spectra on 10 [micro]m Ti[O.sub.2] photoelectrodes in Figure 3(b) are slightly higher than those of dye Z907 where their quantum efficiency spectra in Figure 3(c) are comparable.
Where A o and A t are the initial absorbance of the dye at the time zero before the initiation of reaction and at reaction time (min), respectively.
At regular intervals of time, samples were drawn, centrifuged using a REMI laboratory centrifuge, and the dye concentration was analysed by spectro-photometric analysis (APHA, 1980) using a UV-Vis Spectrophotometer (Elico-BL 198) at 600 nm.
Dye powder (4g) was added in 100ml water (4%) for the preparation of dye extract liquor.
[ClickPress, Tue Jul 23 2019] It has been observed that, the global market for Direct Organic Paper Dyes Market would be experiencing steady growth marked in million US$ by 2025.