Difference between dye and pigment

  • Thread starter Thread starter fog37
  • Start date Start date
  • Tags Tags
    Difference
Click For Summary

Discussion Overview

The discussion revolves around the chemical differences between dyes and pigments, exploring their definitions, solubility, and applications in various contexts, such as textile manufacture. Participants question the clarity of these definitions and the potential for overlap between the two categories.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that pigments are generally insoluble while dyes are soluble, but this distinction may not be universally applicable.
  • Others question whether the definitions of dye and pigment are precise enough to allow for consistent classification, suggesting that some substances might fit both categories.
  • It is noted that solubility can vary depending on the solvent used, complicating the classification further.
  • A participant cites a definition from a source indicating that colorants can act as either pigments or dyes based on their vehicle, and mentions the concept of lake pigments formed from dyes.
  • In the context of textile manufacture, one participant specifies that pigments are particulates while dyes are soluble colorants, providing an example of a widely used pigment (TiO2).

Areas of Agreement / Disagreement

Participants express uncertainty about the definitions of dyes and pigments, indicating that multiple competing views remain regarding their classification and properties.

Contextual Notes

The discussion highlights limitations in the definitions of solubility and the classification of colorants, suggesting that practical applications may influence how substances are categorized.

fog37
Messages
1,566
Reaction score
108
Hello Forum,

What is the chemical difference between a dye and a pigment? Are most objects around us colored by pigments or dyes? Both are responsible for giving color to objects...

I know that pigments are insoluble while dyes are soluble...fog37
 
Chemistry news on Phys.org
Are you sure these things are defined precisely enough to make classification always possible? Or - are you sure there are no substances that can be classified as both?

Also note that "solubility" is a too not well defined. Everything dissolves to some extent. Whether - for practical purposes - we call something soluble or insoluble, often depends on application.
 
Hello Borek,

I agree about solubility: it all depends on the solvent used.

As far as the distinction between dye and pigment, I am not sure. I always hear about pigments in relation to color...
 
From Wiki, "A distinction is usually made between a pigment, which is insoluble in its vehicle (resulting in a suspension), and a dye, which either is itself a liquid or is soluble in its vehicle (resulting in a solution). A colorant can act as either a pigment or a dye depending on the vehicle involved. In some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt. The resulting pigment is called a lake pigment. The term biological pigment is used for all colored substances independent of their solubility."
 
In textile manufacture, pigments are particulates and dyes are soluble colorants. A widely used pigment is TiO2.

Chet
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 15 ·
Replies
15
Views
9K
  • · Replies 5 ·
Replies
5
Views
9K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
Replies
10
Views
3K
Replies
5
Views
3K
  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K