Chemistry

Shakira Cruz                                                                                                                 2/15/2014
H23                                                                                                                               Chemistry



The Tie Dye Experiment

Objective:

To use the process of dying frabrics to illustrate chemical reactions, equilibrium, chemical bonding and PH.

Pre- Lab Questions:

1.  Where did the art of dying fiber originate?  The art of dying fiber originate from China and India.
2.  Originally, what type of substances were used to dye?  Rubber bands, a shirt, and a lot of ink dyes.  Also plants, juices, flower, bark and leaves.

 3. What are the fibers of the shirt made from? Fibers of the shirt are made of cotton.
4.  What chemical interactions is occurring when fibers are died? High quality dyes which is chemically bond to the molecules of the fabric and could never be washed out.

History

In India or China, no later than 2500 B.C. the art of dying clothing fibers was orignated.  The common dyes came from flowers, leaves, and roots. William Henry Perkin began in 1856 the synthetic organic chemical industry by accidentally discovering the purple dye, mauveine.  It was about 00 years after William Perkins first discovery, fiber reactive dyes capable of forming covalent linkage with the fiber were discovered.

Chemistry of Dying Fabrics:

Most dyes only stain the cloth and wash out a little each time the cloth is clean. The fiber active dye which is the high quality dyes are chemically covalent bond to the molecules of the fabric and can never be washed out.  The dye molecules carry a "chromophore," which absorbs varying spectrums of light, allowing only certain spectrums to reflect. 

Post Lab Questions:

1.  If you dye a rainbow spiral on a shirt and then soaked it in a black dye both, the results would be a black shirt with a rainbow spiral pattern. Why doesn't the entire shirt dye black? It all depends where the black ink is placed on the shirts. Since it is separated by the rubber bands.

 

 

 2.  What is the purpose of soaking the shirts in the hot water for five minutes? The purpose is that it will increase the PH by soaking the fabric in calcium carbonate, which would release a "H" atom from the cellulose molecule. 
3.  Why is 100% cotton the best type of cloth to use with fiber reactive dyes? Cotton is the best because the fibers are naturally hollow which makes it easier to dye.
4.  What are some advantages of fiber reactive dyes? Some reactions is that it gives strong color on the fabric given.
5.  Explain how ionic bonding is used to dye the shirts in the lab? The dye bonds with cellulose molecule of the removed atom.

Procedure:

• Step 1: With a permanent marker , write your name on the cloth you will be 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 five 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 diagram, tie your cloth in one (or a combination of) the methods showing 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. 

 

 

 

1. Write a synopsis of what occurred before the dying of the shirt:

Before the dying of the shirt, we had to roll our shirts and tie it with a rubber band, then leave it in warm water for at least five minutes. Next we rinse out the shirt to make sure it is not leaking water and section the shirt off with rubber bands.

2.  Explain the process used to dye your shirt pattern typing method:
After you are done rinsing your shirt off, you would then section your shirt with rubber bands.  Once that is done, you would then place the dye colors on to which spot you want the dye color to be at. Then when you are done you would place the shirt in a bag and leave it sit for 24 hours.

3.  After the shirt sat for 24 hours, describe the pattern of the shirt.
Once the shirt sat for 24 hours, you would dip it in cool water for at least 3 minutes to rinse off the extra dyes. Once you did that you would then start to take off the rubber bands that were attached to the shirt. Then dip it three times in fresh water, rinse the water out so that it won't leak, and place your shirt outside or somewhere esle so that your shirt can get dry.