Commonly stocked dyes that work with cotton

  • Thread starter mishima
  • Start date
  • Tags
    Work
In summary, the author is thinking of dyeing some lab coats using substances they have on hand and is worried about the environmental consequences of doing so.
  • #1
mishima
576
43
We had a few boxes of lab coats recently donated, and I was thinking of tie-dyeing some for fun. Instead of getting a commercial kit, I wanted to use substances we already had in stock.

I have plenty of sodium carbonate and off the top of my head Congo Red. There is a huge selection of other pigments and dyes that I have never really used. I am fairly sure we have nearly everything on this list:

http://en.wikipedia.org/wiki/List_of_dyes

Which of these will work with cellulose? I am assuming I need to find dyes with chlorine in their structure, like crystal violet or methylene blue. Is this a gross over-simplification?
 
Chemistry news on Phys.org
  • #2
Is this a gross oversimplification? YES.
Its almost certain that the coats are treated. A priori you can't know what conditions were used.
Generally (and I wonder if this isn't already laid out in wikipedia, but you didn't bother to look...) the dying (or is it dyeing?) process is: Treat cotton (to increase dye absorption ), expose to dye, make dye insoluble in situ, revert cotton, rinse excess. This is can be accomplished by changing pH or by use of a selected counter ion. You want a dye that is very insoluble at both physiological pHs as well as in a washing machine, but is soluble under conditions used in the dye process. Obviously, the process shouldn't destroy (much of) the structure of the cellulose. I'm sure the easily available patent literature lists scores of dyes along with their processing requirements (but I'm too lazy to do the work for you). Please note that your idea of "fun" is profoundly environmentally UNfriendly, not to be a spoil sport or anything.
 
  • #3
Well, here is the dyeing process I had known about already:
1. soak cloth in sodium carbonate to increase pH.
2. Twist into pattern.
3. Apply dye. This forms HCl (takes an H from the cellulose hydroxyl groups and a Cl from the dye) now the two are oppositely charged and attract, forming a CO covalent bond (the reaction takes overnight to complete). This is why I thought I should be on the lookout for dye molecules with Cl in their structure.

I also thought this was fairly commonplace in Chemistry departments and that someone with experience could help me out, rather than researching every stain/dye/pigment in our stock individually on my own (because there are a great number of them...).
 

FAQ: Commonly stocked dyes that work with cotton

What are the most commonly stocked dyes that work with cotton?

The most commonly stocked dyes that work with cotton include fiber reactive dyes, direct dyes, and vat dyes. These dyes are specifically formulated to bond with cotton fibers, resulting in vibrant and long-lasting colors.

How do fiber reactive dyes work with cotton?

Fiber reactive dyes are designed to chemically bond with the cellulose fibers of cotton, creating a permanent bond that resists fading and washing out. These dyes require the use of soda ash and typically need to be heated for optimal color absorption.

Can direct dyes be used with cotton?

Yes, direct dyes can be used with cotton. These dyes are water-soluble and do not require a mordant or fixative. They work by attaching to the fibers of the cotton and are typically used for lighter or pastel colors.

What is the difference between fiber reactive dyes and vat dyes for cotton?

The main difference between fiber reactive dyes and vat dyes is the type of chemical reaction that occurs. Fiber reactive dyes chemically bond with the cotton fibers, while vat dyes require a reduction process to attach to the fibers. Vat dyes are typically used for darker colors and require more extensive preparation and dyeing techniques.

Are there any dyes that should not be used with cotton?

Yes, acid dyes and disperse dyes should not be used with cotton. These dyes are designed for synthetic fibers and will not bond with cotton. Attempting to use these dyes on cotton will result in a weak or non-existent color bond.

Hot Threads

Recent Insights

Back
Top