Chemicals in every day life: Dyes

Chemistry in Dyes


Natural dyes are extracted from natural sources. They are used for making coloured fabrics. Probably, the earliest known natural dyes were indigo (a blue dye) and alizarin (a red dye). These were obtained from plants.
Definition of Dyes
A dye is a coloured substance that can be applied in solution or dispersion to a substrate, giving it a coloured appearance.
Usually the substrate is a textile fiber, but it can also be paper, leather, hair, fur, plastic material, wax, a cosmetic base or a foodstuff. Now a days synthetic dyes are used for dyeing purpose.

Classification of Dyes

Dyes are classified either according to their constitution or method of application.

1. Classification of dyes based on Constitution

This classification is based on the distinguishing structural units present in the dye.

1. Azo
2. Nitro
3. Phthalein
4. Triphenyl Methane
5. Indigoid
6. Anthraquinone



2. Classification of dyes based on Application


Depending upon the process of application the dyes are classified as

1. Acid Dyes
2. Basic Dyes

3. Direct dyes
4. Disperse Dyes

5. Fibre reactive dyes
6. Insoluble azo dyes

7. Vat dyes
8. Mordant dyes

We will update this posts soon, until then you can refer http://en.wikipedia.org/wiki/Dye

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