The purpose of this lab is to apply our understanding of chemistry of a common substance. We have already learned how to do a chemical reactions and electron transfer. We've also already been taught how to explain the difference between chemical and physical properties of matter and how to write and balance chemical reactions.
Dyes in the early years were based on how wealthy you were or if you were a priest or not. Depending on the colors of dye that someone was wearing you could tell what rank or social standing someone was in. As dyes became more popular in the 1960's people wore them to represent piece and freedom after the Vietnam War. It was an artistic expression for the "hippie" era.
The different colors are due to the excitation of electrons from an absorption of energy engulfed by the chemical. The final color of the dye that is seen by us is not the color that had been absorbed, but the complimentary color from the removal of the absorbed wavelengths.
Only certain types of dyes can react with certain types of fibers because the chemical reaction between the dye and fiber depends on the dye being used. For example fiber reactive dye attaches itself to plant materials such as Cotton, Linen, Hemp, ect. Therefore the chemical reaction of the dye actually becomes a part of the fabric. Also each type of dye has a different chemical reaction when it comes into contact with different types of fabrics.
Color is a perceptual characteristic of light, and light is composed of many color that are seen in the visible spectrum of light such as red, orange, yellow, green, blue, and violet. Objects absorb certain wavelengths and reflect colors back to us. Therefore we see the wavelengths of light as color.
The types of dyes and their uses:
- Direct dyes- Cotton, Cellulosic, and Blended fibers
- Vat dyes- Cotton, Cellulosic, and Blended fibers
- Sulpheur- Cotton, Cellulosic fiber
- Organic Pigments- Cotton, Cellulosic, Blended fibers, Paper
- Reactive- Cellulosic fibers and fabrics
- Disperse Dye- Synthetic fibers
- Acid dyes- Wool, Silk, Paper, Sythetic fibers, Leather
- Azoic- Printing inks and pigments
- Basic- Silk, Wool and Cotton
A Fiber Reactive Dye is one of the most effective and and permanent dyes because it actually forms a covalent bond with the cellulose or protein molecule and has become part of the fabric itself. fiber reactive dyes are best used on cotton, rayon, silk, linen, lyocell, hemp and any other cellulose fiber.
Safety:
Chemical Structures:
Safety:
- Gloves
- Apron
- Old Clothes
Materials:
- Shirt (Cotton)
- Dye Colors
- Pipette
- Small Beaker
- News Paper
- Plastic Bag (Garbage Bag)
- Gloves
- Apron
- 1 1/2 cups Sodium Carbonate
- Rubber Bands
Chemical Structures:
Indigo- The compound found in all indigo producing plants is indican, which is a molecule that is attached to glucose. Indican is colorless, but after much fermentation from an alkaline base it splits off the the glucose and produces an indoxol molecule. The indoxal reacts with oxygen which gives off the blue colored indigo.
"The molecule responsible for the characteristic yellow-orange of saffron is known as crocetin, and its structure is reminiscent of the orange color of B-carotene, each having the same chain of seven alternating double bonds indicated, below, by the brackets." (Napoleon's Buttons)
Carminic acid- A red dye from the ancient times, that comes from the crushed bodies of the female cochineal beetle, and contains numerous OH groups.
Echinochrome- A red pigment found in sand dollars and sea urchins.
Anthraquinone- A based compound found in insects, plants, fungi, and lichens,and also colorless, butwith the two OH groups there is enough single and double bonds in the rest of the molecule so the alizarin can absorb light.
B-Carotene- Since this molecule has alternating double and single bonds light is absorbed and it creates an orange color like pumpkins, or carrots.
Mauveine- It is thought that Perkin's purple color was obtained from a mixture of very closely related compounds that may have looked something like the following structure below.
Picric Acid- Hada strong yellow hue and was not easily obtained.
Kermesic Acid- Obtained from animals and shows as a bright red color and wasn't very popular.
Naphthoquinone- A colorless molecule, but color that derives from this molecule can be Juglone, found in walnuts, or lawsone, found in Indian henna and used mainly for hair dyes.
Indican- from indigo and woad plants and colorless.
Indigo- A synthetic form of indigo that went through seven different chemical reactions to finally get indigo.
Tyrian Purple- Created from a mucus that could be obtained from a marine mollusk or snail. This molecule is attached to a glucose unit and can only the vibrant tyrian purple be seen through oxidation of the mollusk mucus.
Procedure:
- Wash fabric to remove oils or sizing that may affect the outcome of the dyeing process.
- Soak fabric in 1 1/2 cups of sodium carbonate and warm water. After soaking wring out the shirt for excess fixer solution.
- Fold, twist and/or pinch shirt into the design you have chosen.
- Collect dyes wanted for your shirt in small beakers.
- Lay out newspaper and place shirt on top before tie dyeing.
- Use the pipette to squirt the dye onto your shirt in the design you want to create.
- When you have finished dyeing both sides identically, leave it folded up and put it in the plastic bag.
- Let your dyed shirt sit in the bag for 6-24 hours before rinsing it out to give the dyes enough time to set in.
- Rinse the shirt in a stainless steel sink so the dyes don't stain the appliances. Rinse until the water running through the shirt runs clear.
- Wash shirt in the laundry either with dark clothes or by itself so color doesn't leak into whites or expensive clothing.
- Once shirt has been dried it is ready to be warn!
Put in bag to let the dyes soak in!
Rinsing my shirt out!
The final outcome!
