Jan 24, 2018 - Rules and style conventions for expressing values of quantities Rules and style conventions for writing SI units and quantities shortened to a. Pigments – syntheses and properties - » h. Zollinger colour chemistry -syntheses. Applications of organic dyes and pigments, vch, weinheim. Part 2: dyes. And tara adams the chemistry of pigments - gamesya - download the chemistry of. Chemistry of pigments pdf file for free from our online library pdf file: the.

Main article: The majority of natural dyes are derived from plant sources:,,,, and,,. Most dyes are synthetic, i.e., are man-made from petrochemicals. Other than pigmentation, they have a range of applications including, optical media () and (). History [ ] dyeing dates back to the period. Throughout history, people have dyed their textiles using common, locally available materials. Scarce dyestuffs that produced brilliant and permanent colors such as the natural invertebrate dyes and crimson were highly prized luxury items in the ancient and medieval world. Plant-based dyes such as,,, and were important trade goods in the economies of Asia and Europe.

Across Asia and Africa, patterned fabrics were produced using techniques to control the absorption of color in piece-dyed cloth. Dyes from the such as and were brought to Europe by the treasure fleets, and the dyestuffs of Europe were carried by colonists to America. Dyed fibers have been found in the in a prehistoric cave dated to 36,000. Evidence shows that, particularly in and, has been widely carried out for over 5,000 years. Early dyes were obtained from, or sources, with no to very little processing.

By far the greatest source of dyes has been from the, notably roots, berries, bark, leaves and wood, only few of which are used on a commercial scale. The first synthetic dye,, was discovered by in 1856. Dyes are classified according to their solubility and chemical properties. Are - dyes that are applied to such as,, and modified using neutral to acid dye baths. Attachment to the fiber is attributed, at least partly, to salt formation between anionic groups in the dyes and groups in the fiber.

Acid dyes are not substantive to fibers. Most synthetic food colors fall in this category. Examples of acid dye are Alizarine Pure Blue B,, etc. Basic dyes are water-soluble dyes that are mainly applied to, but find some use for wool and silk. Usually is added to the dye bath to help the uptake of the dye onto the fiber. Basic dyes are also used in the coloration of.

Direct or is normally carried out in a neutral or slightly dye bath, at or near, with the addition of either (NaCl) or (Na 2SO 4) or (Na 2CO 3). Direct dyes are used on, paper,, wool, silk.