From Common Dyes and Their Properties
Classification of Dyes
Dyes are classified based on their origin, application, and chemical properties. Dye manufacturers classify dyes according to their chemical properties, while dyers classify dyes based on the method of application.
Classification Based on Origin of Dyes
Most dyes are organic molecules and are complex in nature. The synthesis of organic dyes began with azulene synthesis. Before that, colors were made from pigments.
As a result, dyes can be classified as natural and synthetic, according to their sources of origin.
Natural dyes are derived from nature through organic and inorganic materials or sources. Logwood is a natural dye obtained from plants. It saturates silk, wool, cellulose acetate, and nylon with a deep black color. Tyrian purple is obtained from animals and Prussian blue is an inorganic dye obtained from naturally occurring minerals.
Synthetic dyes became popular because they were easy-to-use, less expensive and had wider range of colors. Synthetic dyes are obtained by adding chemicals to natural dyes. For example, artificial alizarin is a synthetic dye synthesized from coal tar anthracene. Synthetic dyes are used for modern clothing.
Classification Based on the Dyeing Process
Dyeing process is accomplished by dissolving or dispersing the colorant in a suitable solution (usually water) and bringing this system into contact with the material to be dyed. According to the process of dying, dyes are classified into the following types:
Acid dyes are anionic dyes soluble in water.
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