The art of dyeing clothing fibers originated in India or China no later than 2500 B.C. Most natural dyes came from parts of plants such as the bark, berries, flowers, leaves, and roots.
In 1856, William Henry Perkin began the synthetic organic chemical industry by accidentally discovering the purple dye, mauveine,
when he tried to produce quinine from aniline.
About 100 years after Perkin’s first discovery, fiber-reactive dyes capable of forming covalent linkages with the fiber were discovered.
In 1856, William Henry Perkin began the synthetic organic chemical industry by accidentally discovering the purple dye, mauveine,
when he tried to produce quinine from aniline.
About 100 years after Perkin’s first discovery, fiber-reactive dyes capable of forming covalent linkages with the fiber were discovered.
Some dyes only stain the cloth, and wash out a little each time the cloth is laundered. High Quality dyes (fiber-active dyes) actually chemically (covalent) bond to the molecules of the fabric and can never be washed out. The dye molecules carry a “chromophore”, which absorb varying spectrums of light, allowing only certain spectrums to reflect.
Cotton is made of long strands of cellulose molecules, all twisted together. Cotton is ideal for dying because the fibers are naturally hollow, and the dye molecules will form bonds on both the inside and outside of the fiber. If you put molecules of dye and cotton together, very little will happen until the atoms on the surfaces of the molecules are prepared for bonding.
This can be done by either increasing the temperature or the pH of the fiber and dye. In this lab, we will do the latter, increasing the pH by soaking the fabric in calcium carbonate, which causes the releases a H atom from the cellulose molecule. The removal of the H atom leaves the cellulose molecule with some atoms that do not have stable octets. As a result, the dye can bond to the cellulose molecule at the site of the removed H atom.
After the dye is applied, it is allowed to react in a desirable host environment for up to 24 hours. After this time, the bonding sites on the cellulose should be saturated with dye molecules. Excess dye molecules that have not bonded permanently are washed away using warm water rinse and a dye-carrying detergent.
Objective:
Use the process of dying fabrics to illustrate chemical reactions, equilibrium, chemical bonding, and pH.
Pre-Lab:
1.) Where did the art of dying fibers originate?
The art of fibers originates from India or China.
2.) Originally, what type of substances were used to dye?
The substances that were used to dye fibers were fruits, vegetables, plants, and even insects. Some of the fruits are berries (such as blackberries, blueberries, strawberries, etc), pomegranate, cherries, and kamala. Some vegetables can be onions, spinach, cabbage, and beetroots. Some plants that can be used are goldenrod, carrot tops, and indigo.
3.) What are the fibers of the shirt made of?
The cotton fibers are made up of long strands of cellulose molecules.
4.) What chemical interaction is occurring when fibers are dyed?
The chemical interaction that is occurring when fibers are dyed is a co-valent bond between the fibers of the cellulose and the dye.
Designs For Shirts:
Procedure:
Designs For Shirts:
Procedure:
Step 1:Soak your cloth in the hot water for about 5 minutes. Be sure you put it in the tub marked for your period.
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Step 2: Put on a pair of gloves, remove your cloth from the soaking tub and wring out. Tie your cloth in one (or a combination of) the methods using string or rubber bands.
Step 4: Dye application. Apply the dye using the applicator bottles. Be aware that mixing will occur where the dyes come in contact with each other. Using complimentary colors (purple and yellows, blues and orange, or red and green) near each other usually produces a brownish black color. Also, the more dye you put on a given spot, the less white will remain on the final product.
Step 5: Place your dye-soaked item in a grocery or other plastic bag. No pooling of liquid should appear in the bag.
Step 6: After the cloth has soaked for at least 24 hours, open the bag, remove the item, and rinse it several times with warm water, before removing strings or rubber bands. Once it is rinsing clean, remove the ties and rinse several times again until it is rinsing clean.
**The first time you wash it, place it alone in the washing machine with just a small squirt of dish washing liquid like Dawn or Joy. Do not use laundry detergent.
Data:
1.) Write down a synopsis of what occurred before the dyeing of the shirt. Before Dying the shirt, I soaked the shirt in water, and then tied it to the design of my preference. 2.) Explain the process used to dye your shirt - pattern, tying method. To tie my shirt I just did a spiral from the bottom right corner to give it a different look. I grabbed the shirt and started turning it, making it look like the picture below. When I dyed my shirt, I placed the top of the bottle directly on the fabric so that my design would look better. Since I didn't want my shirt to be completely covered in dye, I didn't make sure that the ink was in the crevices inside of the shirt, which in most cases you should.
3.) After the shirt sat for 24 hours, describe the pattern of the shirt - picture, if possible.
My shirt has a spiral starting from the bottom left corner, up. The shirt isn't completely covered in dye, because I wanted some of it to stay white.
1.) Write down a synopsis of what occurred before the dyeing of the shirt. Before Dying the shirt, I soaked the shirt in water, and then tied it to the design of my preference. 2.) Explain the process used to dye your shirt - pattern, tying method. To tie my shirt I just did a spiral from the bottom right corner to give it a different look. I grabbed the shirt and started turning it, making it look like the picture below. When I dyed my shirt, I placed the top of the bottle directly on the fabric so that my design would look better. Since I didn't want my shirt to be completely covered in dye, I didn't make sure that the ink was in the crevices inside of the shirt, which in most cases you should.
My shirt has a spiral starting from the bottom left corner, up. The shirt isn't completely covered in dye, because I wanted some of it to stay white.
Post-lab:
1.) If you dyed a rainbow spiral on a shirt and then soaked it in a black dye bath, the result would be a black shirt with a rainbow spiral pattern. Why doesn't the entire shirt dye black? Since there is already a bond between the cotton and the dye, the black dye wouldn't bond with any of the cotton fibers because they are already bonded to something. 2. What is the purpose of soaking the shirts in the hot water for 5 minutes? The purpose of soaking the shirts in hot water for 5 minutes is to break any bonds it has so that it can bond with the dye. 3. Why is 100% cotton the best type of cloth to use with fiber reactive dyes?
The 100% cotton cloth is best to use with fiber reactive dyes because it absorbs liquid best and also has a negative charge to the dye, making it bond.
4. What are some advantages of fiber reactive dyes?
An advantage of fiber reactive dyes is that since the colors are bright, they create a co-valent bond and produce many colors.
5. Explain how ionic bonding is used to dye the shirts in this lab.
Since the fibers and the dye have opposite charges, they attract and stay together. When they're together, they share electrons, making it a co-valent bond.
Final Product:
Sites Used:
http://www.planet-science.com/categories/experiments/chemistry-chaos/2012/06/dye-your-clothes-with-food.aspx
https://www.westminster.edu/acad/sim/documents/STie-dyechemistry_000.pdf
http://www.planet-science.com/categories/experiments/chemistry-chaos/2012/06/dye-your-clothes-with-food.aspx
http://hernando.fnpschapters.org/miscellaneous/dyeing.htm
