How are dyes classified on the basis of structure?

Dyes may be classified in several ways (e.g., according to the chemical constitution, application class, end-use). The primary classification of dyes is based on the fibers to which they can be applied and the chemical nature of each dye. … Reactive dyes react with fiber molecules to form chemical bonds.

What is the structure of dye?

A Dye is a coloured compound due to the presence of chromophore and its fixed property to the acid or basic groups such as OH, SO3H, NH2, NR2, etc. The polar auxochrome makes the dye water-soluble and binds the dye to the fabric by interaction with the oppositely charged groups of the fabric structure.

What are the two classifications of dye?

They are classified into natural dyes and synthetic dyes. Dyes are organic compounds with two components namely Chromophore, which imparts colour and Auxochrome that help in substantivity of dyes. They are classified into natural dyes and synthetic dyes.

What is the classification of solubility dyes?

some cases, based on the solubility, dyes are classified differently. As an example, acid, basic, direct, mordant, and reactive dyes are considered as soluble dyes. Whereas azo, disperse, sulphur, solvent, and vat dyes are some examples of the insoluble dyes, as depicted in Fig.

What structural characteristics give dyes their color?

Unlike most organic compounds, dyes possess colour because they 1) absorb light in the visible spectrum (400–700 nm), 2) have at least one chromophore (colour-bearing group), 3) have a conjugated system, i.e. a structure with alternating double and single bonds, and 4) exhibit resonance of electrons, which is a …

What is dye explain the classification of dyes according to their mode of application?

Dyes are classified in two ways, one, based on the method of application and the other on their parent structure. Based on the method of application: Acid dyes: These are acidic in nature and are used for dyeing animal fibres and synthetic fibres. These can be used for protein fibre such as wool and silk.

What are the characteristics of dyes?

A dye has the following characteristics:
  • It must have a suitable colour.
  • It can be fixed on the fabric either directly or with the help of mordant.
  • It must be resistant to the action of water, acid and alkalies. The groups responsible for colour are called chromophores.
  • These should be unaffected by light.

Why are dyes categorize into two major classification natural and synthetic?

Dye Classification

Broadly, dyes can be classified into natural and synthetic based on the source of origin. Natural dyes can be extracted from natural sources such as fruits, flowers, leaves, roots, barks, etc., whereas synthetic dyes are synthesized in laboratories by the use of chemicals.

What are dyes made of?

The majority of natural dyes are derived from non-animal sources: roots, berries, bark, leaves, wood, fungi and lichens. In the 21st century, most dyes are synthetic, i.e., are man-made from petrochemicals. The process was pioneered by J. Pullar and Sons in Scotland.

What is a dye compound?

Dyes are soluble coloured organic compounds that are usually applied to textiles from a solution in water. They are designed to bond strongly to the polymer molecules that make up the textile fibre. Pigments are insoluble compounds used in paints, printing inks, ceramics and plastics.

What are the characteristics of dye?

A dye has the following characteristics:
  • It must have a suitable colour.
  • It can be fixed on the fabric either directly or with the help of mordant.
  • It must be resistant to the action of water, acid and alkalies. The groups responsible for colour are called chromophores.
  • These should be unaffected by light.

What is fabric dye made of?

Natural fabric dyes are derived from plants, animals and invertebrates or minerals. The sources of natural dyes are roots, nuts, insects, flowers, berries, bark, leaves, wood and other biological sources such as fungi and linchens.

What is dye and its uses?

Dyes are used primarily to impart color to textiles, leather, paints, photographs, cosmetic and pharmaceutical products, biological stains, and food. Many natural dyes have been largely replaced by synthetic dyes that were developed at the end of the nineteenth century.

What is difference between pigment and dye?

Dyes and pigments are the main forms of colourant. The main difference between them is that dyes are soluble and pigments are insoluble and are suspended in a medium or binder. This is due to the difference in particle size of dyes and pigments which affects the way they behave.