Science of Tie Dye

We finally got to apply the science topics of chemistry we learned about yesterday to do our tie dye today. Students learned how the soda ash raises the Ph of the shirt and makes the already negatively charged cotton even more negative. This allows the fiber reactive dye, which is positive, to covalently bond. Shirts are sitting in the sun outside to speed up the chemical reaction of the bonding. They will use a special textile detergent to release any dye not bonded in the shirt, ensuring it won't bleed or run in future washes. Science can be so fun....and bright!