Colorful Chemistry

This assignment started on February 10, 2014. Isamar Nunez, 5th period Chemistry. 

Objective:

• Use the process of dying fabrics to illustrate chemical reactions, equilibrium, chemical bonding, and pH. 

Pre-Lab Questions:

1. Where did the art of dying fibers originate? The art of dying fibers originate in India or China no later than 2500 BC.
2. Originally, what type of substances were used to dye? The types of substances used were berries, such as, cranberries, blueberries, and black raspberries. Including, vegetables like spinach and cabbage. 
3. What are the fibers of the shirt made of? The fibers of the shirt are made of cotton. 
4. What chemical interaction is occurring when fibers are dyed? The chemical interaction that is occurring when fibers are being dyed is a hydrogen atom is lost when the pH of the shirt is being increased. When that hydrogen atom is released the oxygen atom is able to form a bond with the dye molecule. 

My design:

                      

History of Dyeing Fabrics:

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.

Chemistry of Dyeing Fabrics:

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.

Lab Safety Rules:

1. Always wear safety glasses in the lab.
2. Wear disposable plastic gloves and aprons.
3. Don't get sloppy or squirt others with the dye solutions.
4. Use caution handling the solutions. These are strong chemicals that can be harmful.

Procedure: The point of tie dying is to prevent the dye from reaching the fabric evenly. Any place the dye can’t reach will stay white, or a lighter color. You can accomplish this by folding the fabric, tying it with string, using rubber bands.

Step 1: With a permanent marker, write your name on the cloth you will be tie dying. There will be many other shirts in the lab during this activity; be sure yours is marked to avoid losing it.

Step 2: Soak your cloth in the hot water for about 5 minutes. Be sure you put it in the tub marked for your period.

Step 3: Put on a pair of gloves, remove your cloth from the soaking tub and wring out. Using the below diagrams, tie you cloth in one (or a combination of) the methods shown 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 marked clearly with your name. 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. At this point, you can hang it to dry or place it in another bag to take home and wash.

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 dyeing the shirt, the shirt was soaked in warm water for five minutes. Then, tied into a pattern.
2. Explain the process used to dye your shirt - pattern, tying method. The pattern I used to tie my shirt was the spiral pattern. First, you pinch the center of the shirt, and then start spinning the shirt into a spiral. You tie the shirt in rubber bands, and finally, dye each section.
   
3. After the shirt sat for 24 hours, describe the pattern of the shirt - picture, if possible. The colors of on the shirt were blended together. The main colors that shined were orange and purple.

Final Outcome:

Post-Lab Questions:

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? The entire shirt doesn't turn black because the original bonds cannot be broken by black dye. The black dye can go to the white spaces in the shirt since, that white space has not formed a bond with the other dyes.
2. What is the purpose of soaking the shirts in the hot water for 5 minutes? The purpose of soaking the shirt in the hot water for five minutes was to increase the pH.
3. Why is 100% cotton the best type of cloth to use with fiber reactive dyes?
4. What are some advantages of fiber reactive dyes? The advantages of fiber reactive dyes are long-lasting, and brighter colors.
5. Explain how ionic bonding is used to dye the shirts in this lab. When heating the fibers the bond between the oxygen and hydrogen atoms has been broken causing the oxygen atom to have a negative charge. Now, the oxide can bond with the dye molecule since oxide has a negative charge and the dye molecule has a positive charge.

Sources: 
http://www.highland.k12.in.us/cms/lib04/IN01001438/Centricity/Domain/434/tie_dye_flinn_instructions.pdf
http://www.prairiefibers.com/Plant%20Color%20List.htm
http://www.planet-science.com/categories/experiments/chemistry-chaos/2012/06/dye-your-clothes-with-food.aspx
http://www.pburch.net/dyeing/fiberreactive.shtml