A substantive dye or direct dye is a
dye
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy
Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...
that adheres to its substrate, typically a textile, by non-ionic forces.
Overview
The amount of this attraction is known as "substantivity": the higher the substantivity the greater the attraction of the dye for the
fiber
Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...
.
Substantive dyes work best on textiles with high contents of cellulose, such as cotton.
In contrast to direct dyes, wool and leather goods are dyed by the process of
ion exchange
Ion exchange is a reversible interchange of one species of ion present in an insoluble solid with another of like charge present in a solution surrounding the solid. Ion exchange is used in softening or demineralizing of water, purification of ch ...
, exploiting the cationic nature of proteins near neutral pH. The development of substantive dyes helped make
mordant
A mordant or dye fixative is a substance used to set (i.e., bind) dyes on fabrics. It does this by forming a coordination complex with the dye, which then attaches to the fabric (or tissue). It may be used for dyeing fabrics or for intensifying ...
dyes obsolete.
[
Substantive dyes are set in a slightly basic or neutral environment at temperatures close to boiling point. They are set by formation of aggregates of dyes within interstices of the fibres. Aggregation is enhanced by extended aromatic rings.][Klaus Hunger, Peter Mischke, Wolfgang Rieper, Roderich Raue, Klaus Kunde, Aloys Engel. "Azo Dyes". ''Ullmann's Encyclopedia of Industrial Chemistry''. Weinheim: Wiley-VCH .]
Gallery
File:Pontamine sky blue.svg, Direct Blue 1
Direct Blue 1 is an organic compound that is one of many azo dye
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important f ...
File:TrypanBlueSalt.png, Trypan blue (Direct Blue 14), which also exhibits medicinal properties
File:Direct Blue 15.svg, Direct Blue 15
Direct Blue 15 is an organic compound that is classified as an azo dye. It is a dark blue water soluble solid. It is a popular substantive dye, which means that it useful for dying cotton and related cellulosic materials. It is produced by az ...
See also
* Reactive dye
In a reactive dye, a chromophore (an atom or group whose presence is responsible for the colour of a compound) contains a substituent that reacts with the substrate. Reactive dyes have good fastness properties owing to the covalent bonding that o ...
References
{{Dyeing
Dyes