The chemistry and application of dyes pdf
Natural Dyes for Textiles - 1st EditionChapter 4: Dyeing application of each dye on cotton, silk and wool with fastness properties, CIELab values and shade card. Natural Dyes for Textiles: Sources, Chemistry and Applications is an in-depth guide to natural dyes, offering complete and practical coverage of the whole dyeing process from source selection to post-treatments. The book identifies plants with high dye content that are viable for commercial use, and provides valuable quantitative information regarding extraction and fastness properties, to aid dye selection. The book presents newer natural dyes in detail, according to their suitability for cotton fabrics, silk fabrics, and wool yarn, before describing the application of each dye. Extraction of plant parts for isolation of colorants, chromatographic techniques for separation, spectroscopic analysis of the isolated colorants, structure elucidation, biomordanting, pretreatments, and post-treatments, are also covered.
Dye , substance used to impart colour to textiles , paper , leather , and other materials such that the colouring is not readily altered by washing, heat, light , or other factors to which the material is likely to be exposed. Dyes differ from pigments , which are finely ground solids dispersed in a liquid, such as paint or ink, or blended with other materials. Most dyes are organic compounds i. Pigments generally give brighter colours and may be dyes that are insoluble in the medium employed. Colour has always fascinated humankind, for both aesthetic and social reasons. Throughout history dyes and pigments have been major articles of commerce.
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To browse Academia. - A dye is a chemical compound that is soluble in solvents or binder. Dyes are used for dyeing of materials eg plastics, paper, food, inks,
NCBI Bookshelf. Unlike most organic compounds, dyes possess colour because they 1 absorb light in the visible spectrum — nm , 2 have at least one chromophore colour-bearing group , 3 have a conjugated system, i. When any one of these features is lacking from the molecular structure the colour is lost. In addition to chromophores, most dyes also contain groups known as auxochromes colour helpers , examples of which are carboxylic acid, sulfonic acid, amino, and hydroxyl groups. While these are not responsible for colour, their presence can shift the colour of a colourant and they are most often used to influence dye solubility.