What are dyes?:
Dyes are a natural or synthetic substance used to add a color or change the color of something. Dyes are used for a variety of things like clothing, hair, and food. Mentioned in chinese literature around 3000 B.C, dyes was the human’s first attempt at chemistry and continues to be a booming chemical industry. Dyes are much easier to acquire now then back before synthetic dyes. Dyes were hard to make and the dye itself had several problems such as the color wearing off after one wash and the color range was limited to 3 or 4 colors. Now, thanks to synthetic dyes created by William Henry Perkins in 1856, there is a variety of colors and mordants were invented to help hold the color into the fabric. There are 2 different types of dyes, inorganic and organic. Organic dyes have present carbon rings/chains and are derived from plant products. The colors are often brighter than inorganic dyes and are very transparent and usually cost a bit more. Inorganic dyes have cations of metals that are found with non-metallic anions. The colors are usually more dull, they are more opaque, but they are less expensive than organic compounds. Dyes were a great contributions to history and people rarely think of how dyes are beneficial to our lives.
The History Behind Dyes:
Dye have been around since 3000 B.C. The first synthetic dye, however, was accidentally discovered by William Henry Perkins in 1856. Perkins’ original experiment was synthesize quinine in order to treat malaria. Over his Easter weekend, he was trying to achieve synthesize quinine when one of his trials produced a deep purple solution after being dissolved in ethanol. After putting strips of silk into this solution, he discovered that the color was bright and it was colorfast. This dye would soon be called mauve. This discovery lead to Perkins’ opening his own factory and selling the first ever man made dye.
The first organic chemistry enterprise originated in Germany called “Badische Anilin und Soda Fabrik”. This company was originally suppose to sell inorganic compounds such as caustic soda and soda ash but it soon became active in the dye business. There were other dye companies in Germany as well, such as Bayer Company and Hoechst Company. Even today, these companies make up a sizable portion of the chemical dye industry.
The Chemistry of Dyes:
Dyes are organic compounds incorporated into the fibers of textiles. The molecular structure of these compounds allow the absorption of light. The actual color of the dye depends of the wavelengths of the light that is reflected rather than absorbed. The relationship between the wavelength absorbed and the chemical structure depends on the presence of double bonds alternating with single bonds. Primary colors, blue, red, and yellow, all come from either Indigoton, alizarin, and crocetin. The most unique color is blue, due to the fact it isn’t common in plants. There is only one plant that indigo could be acquired from, the Indigofera tintoria. The indigofera tintoria’s leaves might not appear blue but after indican undergoes fermentation under alkaline conditions, the glucose to produce an indoxol molecule. Then this molecule reacts with oxygen to create its blue color. Red dye comes from alizarin, which comes from roots of the Madder genus. Yellow dye comes from crocetin, which comes from crocus plants. Purple dye, or Tyrian purple, is a very similar molecule to indigo. A tyrian purple molecule is just an indigo molecule with two bromine atoms. Tyrian purple is obtained from the mucus of a mollusk or snail from the Murex genus. Tyrian purple was extremely high in demand, and the shellfish that produced the dye were in danger of becoming extinct in 400 A.D..