Bleachs are known on the market for being able to remove unwanted stains on fabrics, and as the name implies, bleach (whiten), hence also known as "whiteners".
To understand the action of bleaches, it is necessary to know how colors in fabrics are produced. The movement of electrons, as energy levels change, is responsible for coloration. To target a tissue it is necessary to oxidize it, that is, make it lose electrons. Therefore, all bleaches are considered oxidizing agents.
The most used oxidants are Chlorine (Cl2), hypochlorites (ClO-) and hydrogen peroxide (H2O2), and sodium (NaClO) and calcium Ca (ClO)2 hypochlorites are the most used by the Industry Textile.
Bleachs can exist either in liquid form (aqueous NaClO solution) or in solid form: Ca(ClO)2 powder.
In addition to being used on clothing, bleach can be used to treat paper and to lighten hair. For this last function, it is generally used hydrogen peroxide (H2O2) at 10 volumes. As in fabrics, the product acts by oxidizing the hair strands, more precisely melanin (dark hair pigment).
Oxidation can also be used in the restoration of paintings (works of art).
By Líria Alves
Graduated in Chemistry
Brazil School Team
Chemistry Curiosities - Chemistry - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/quimica/acao-oxidante-dos-alvejantes.htm
