An acid dye is a dye, chemically a sodium (less often–ammonium) salt of a sulfuric, carboxylic or phenol organic acid. Acid dye is soluble in water and possesses affinity for amphoteric fibers while lacking direct dyes' affinity for cellulose fibers. When dyeing, ionic bonding with fiber cationic sites accounts for fixation of colored anions in the dyed material. Acids are added to dyeing baths to increase the number of protonated amino-groups in fibers.
Some acid dyes are used as food colorants.
Read more about Acid Dye: Description, Structures, Classes of Acid Dyes, Health and Safety
Famous quotes containing the word dye:
“It will help me nothing
To plead mine innocence, for that dye is on me
Which makes my whit’st part black.”
—William Shakespeare (1564–1616)