Tie-dying t-shirts has become a common activity for kids to make their own fun patterns and designs from ordinary white fabric. With various processes and methods that can be used to produce assorted styles, it allows children to use their creativity and experiment with different techniques.
The History
The history of tie-dye dates back as far as the 6th century during the Tang Dynasty in China and the Nara Period in Japan. During this time, natural dyes were made from things such as berries, roots, and flowers. These items would be boiled in water and then used to soak the fabric, giving it its color. Similarly, in India, the process of Bandhani became popular where knots were tied into the fabric to section off some parts which were dyed resulting in beautiful patterns.
In the US, tie-dye has had its ups and downs with it first gaining some popularity in the Roaring 20s due to easy access and low expense. Tie-dye regained popularity during the infamous hippie movement in the 1960s as a way to express creativity. Then again in the 1980s, tie-dye was improved with its incorporation into fashion shows, resistance to fading, more vibrant colors, and more styles. However, these improvements could not have been made without the help of chemistry!
The Process Simplified
Although the process may seem difficult to people trying tie-dye for the first time, it is actually pretty simple. With just a few materials and a little bit of patience, a creative and unique design can be created in no time. Here are the basic steps involved in the process:
- Set up your work area and prepare the supplies.
- Soak the garment in a solution of warm water and soda ash.
- Fold and tie the garment to your liking.
- Apply the dye to the garment.
- Allow the garment to sit to develop.
- Rinse, wash, and let the garment dry.
- Enjoy wearing your tie-dyed masterpiece.
The Science Behind the Process
The two main materials needed for tie-dye are cellulose ((C6H10O5)n) white clothing, which includes any fiber material made from plants such as cotton and linen, and fiber reactive dyes. However, simply putting the dye onto the cloth would not do much as the dye can likely be simply washed away. Therefore, heat must be added or a catalyst such as sodium carbonate can be used.
Sodium carbonate (Na2CO3), also known as soda ash, works by raising the pH of the solution of water and sodium carbonate to a more basic level between 10 and 11. This allows the process of deprotonation to occur where the cellulose fabric loses some of its positively charged hydrogen atoms. The remaining oxygen anions can much more easily attach to the dye molecules allowing the formation of a covalent bond between the cellulose molecules and the dye molecules, where the electrons are shared by two atoms.
An alternative to using sodium carbonate is sodium bicarbonate (NaHCO3), commonly known as baking soda. However, since sodium bicarbonate is less alkaline than sodium carbonate, heat must be used as well to provide the same bright colors.
After waiting up to 24 hours to allow the dye to fully bond to the fabric, the fabric can be washed removing any excess dye. Now, the tie-dyed fabric is finally complete! Considering that covalent bonds are one of the strongest bonds, it is hard for the dye to be removed after it has been bonded so the color on the fabric can last a very long time without fading.
Final Thoughts
Tie-dye is a relatively simple activity that can be done with not many supplies and effort, but it's surprising to learn about its connection to chemistry. As I took my chemistry class in high school last year during virtual learning, there was only so much we can do in terms of experiments and labs online and we missed out on many hands-on activities involving chemistry concepts that we would have normally done in person. Therefore, I find it interesting to see that our knowledge of chemistry can be applied to hands-on projects at home. Many students always wonder when they will ever use what they learned in school in the real world, so it’s always fascinating to discover something with immediate real-world applications such as the chemical reactions involved in tie-dye.