Tie Dye Lab: Post 1

Dyeing fabric is a practice that literally goes back almost to the beginning of time. The first recorded use of dye and dyestuffs was used in China in 2600 B.C., that's 4614 years ago! Alexander the Great even found 190 year old royal purple robes (worth approximately $6 million!) in the Persian empire Susa, when he conquered it in 334 B.C. That brings up an interesting point, purple dyes, more specifically Royal Purple dyes, have long been associated with royalty (hence the name Royal Purple) For generations purple clothes were reserved for only royals, and that may be because the key ingredient for the dye had to be extracted from small mollusks, and that was not an easy job. About 1700 years later Pope Paul II introduced the Cardinal Purples, though these colors were actually scarlet, these too became known as luxury dyes. Now, obviously since the king, queen, and pope were wearing purple and red cloth then everyone else had to wear purple and red cloth too right? The answer is yes, the earliest dyes were highly valuable and constantly sought after, that's probably another reason why dye was reserved for royalty. However, even though dye was rare and valuable, it didn't actually work that great. The cloth the dyes were put on typically were not treated with mordents, so the colors leaked out with every wash and faded in sunlight.

According to Wikipedia, in a fiber reactive dye "a 1)chromophore contains a 2)substituent that is activated and allowed to directly react to the surface of the 3)substrate. Reactive dyes have good fastness properties owing to the bonding that occurs during dyeing." This means that an 1)atom that is responsible for the color of a compound contains

an 2)atom(s) takes the place of another atom(s) occupying a certain position in a molecule and allows it to directly react with the 3)surface of a substance that underlies something else or has a process occur on it. If I simplify this explanation more I would say when you put the dye (color) on the cloth the molecules in the dye replace a molecule in the cloth so that it (the color) may attach itself to the surface of the cloth permanently.

**The words in the Wikipedia definition with a number next to them have a definition with their corresponding number.

The chemical structure of dye molecules and how dye molecules bond with things actually have an interesting story behind them. The following is a photo of and indigo molecule's journey into becoming blue.

The first compund labeled Indican is the compound that comes out of the indigo plant. Indican has an attached glucose unit and is colorless until it is fermented under alkaline conditions (otherwise known as bases) and the glucose unit breaks off. After fermenting in the base Indixal is produced. Indoxal then reacts with oxygen in the air to produce the blue color we know as Indigo. The Indoxal compound doubles and flips to form the actual Indigo compound. 

The following is a photo of the Tyrain Purple compund. It's 'journey' into becoming a Tyrain Purple compoundis much like that of the Indigo, however, it does not need to be fermented. Tyrain Purple is actually a derivitative of Indigo. The compound harvested from the mollusk's secretions has attached Bromine atoms and an attached glucose unit (like the Indigo). When the compound is oxidized in air the color is released. 

 

Now lets talk about how we see colors. When you look around your house, you can tell that everything is a different color, but do you know why? It has to do with the wavelengths emitted from the different colors. The color is a physical property of chemicals that usually comes from the "excitation of electrons" due to the absorption of energy performed by the chemical. What you see is not the color absorbed but the complementary color from the removal of the absorbed wavelengths. I borrowed the picture below from www.societyofrobots.com to show you the kind of wavelengths and colors people can see.

                                 

When the wavelength is within the visible light spectrum (Between 390nm and 700nm) it is called visible light, people cannot see ultraviolet or infrared rays. Something I learned from the Societyofrobots.com is that color does not actually exist, the color we see is actually somewhat of a byproduct of the molecules emitting light. Each molecule is formed differently so it absorbs a different amount of light, thus giving off the colors we see. Each color emits light at different wavelengths and at different frequencies.

 

Now lets talk fibers... yay! In this particular lab we used fiber reactive dyes to tie dye our shirts. Earlier I talked briefly about what a fiber reactive dye actually is, but not what it does, now you'll find out. Certain dyes react better with certain fibers, in our case, cotton. If you plan on using fiber reactive dyes you MUST use a cotton shirt, cotton/polyester blends don't work because polyester is a synthetic fiber and dyes wash out of polyester, as a result you will have a faded shirt, and tie dye is no fun if the colors aren't vibrant. Silk and rayon are also good choices of materials you can dye. If you're not concerned about how rayon wears, rayon is actually the best kind of material to dye because it is made of processed cellulose and the cellulose is more readily available to react with the dyes.

 

Before you actually start putting the colors on your shirt, you have to treat the shirt with a mordant first. Decades of tie-dyers have learned that a mordant is key to a vibrant and long lasting tie dye shirt. Mordants are usually inorganic oxides that combines with a dye to fix it to a material. In other words, mordants are chemicals you need to soak your shirt in so that the dyes don't wash out every time you wash it. In this lab we used Sodium Carbonate. 

Okay, we are finally to the actual dyeing part! Yay! I have prepared step by step instructions and list of materials for you to follow. 

-Materials:

   *Sodium Carbonate

   *Plastic bin

   *5+ sheets of newspaper 

   *A countertop (most likely one you dont mind getting messy)

   * 3 pipettes 

   *Colors of dye

   *Rubber bands

   *A 100% cotton tee shirt (or whatever else you want to dye)

   *A plastic garbage bag

  

Step 1:

   -Fill the bin with enough Sodium Carbonate to soak your tee shirt

      *leave the shirt in there for many hours

Step 2:

   -Take your shirt out and wring out as much liquid as you can

      *Sodium Carbonate is a skin irritant so WEAR GLOVES!

Step 3:

   -Lay your shirt out on the counter and twist or scrunch the pattern you want your shirt to have

      *You dont have to add the newspaper yet

Step 4:

   -Put the rubber bands on your shirt in a cris-cross pattern so that it won't un-fold (use 5 or more bands) Your shirt should be in a small pie-like shape

Step 5:

   -Pour 50-100 mL of each color into their own beakers (if you have 3 colors, you'll need 3 beakers) and put a pipette in each beaker

Step 6:

   -Lay the newspaper on the counter

Step 7:

   -Use the pipette to drop the dyes onto the cloth

      * Be somewhat generous here, you dont want too much white space, but dont use to much or your colors will bleed together. 

***USE COLORS THAT LOOK GOOD MIXED TOGETHER OR LEAVE WHITE SPACE IN BETWEEN***

Step 8:

   -When you think that you are done carfully take the shirt pie off the newspaper and place it inside the garbage bag

      *Tie a knot in the bag

Step 9:

   -Wait for 6+ hours for the dyes to soak in and complete chemical reactions

Step 10: 

   -After 6+ hours take your shirt and the emptied bin outside

      *Fill the bin with water and soak your shirt in it

      *Keep filling the bin and rinsing your shirt until the water isnt overly colorful anymore  

Step 11:

   -Wash shirt in washing machine either by itself or with items you dont mind the dye bleeding on

Step 12: 

   -Wear your shirt!!