Key concepts
Chemistry
Solubility
Solutions
Inks
Dyes
Introduction
Have you ever made a tie-dyed T-shirt? It can be a lot of fun to dye a shirt in bright colors with spiraling designs. In this science activity you will get to dye a T-shirt with your own colorful artwork using only permanent markers. Along the way, you'll find out how solubility helps your drawings leave beautiful designs on the fabric.
Background
You've probably noticed that when a drop of water lands on a piece of paper with words or a picture printed on it, sometimes the ink runs. When this happens, the drop of water is at least partially absorbed into the paper and then flows through it. As the water moves, it carries the ink particles along with it. Why does the water move the ink? This is because of solubility—the ink has combined with the water.
Solubility is an important property of matter. If a chemical is soluble in water, then the chemical will dissolve, or appear to disappear, when it's added to water—or vice versa. This is why the ink can dissolve in the drop of water on the paper and then travel along with the water through the paper.
If a chemical is not soluble, also known as insoluble, then it will not dissolve. Can you think of some things that are insoluble in water? If a piece of paper were printed with ink that was insoluble in water, what would happen when a drop of water fell on it? The ink should remain in place on the paper and would not be carried away by the water flowing through the paper.
Materials
At least two rubber bands
At least two plastic cups
Colorful assortment of permanent markers
Water
70 percent isopropyl alcohol (aka rubbing alcohol)
Medicine dropper
White T-shirt that can be dyed
Newspapers (optional) (This is to protect your work surface.)
Hair dryer (optional)
Preparation
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If you want to protect the surface on which you will be dyeing your T-shirt, cover it with a few layers of newspaper sheets. Note that permanent markers can stain fabric and other materials, so be careful when using them.
Procedure
Lay out the T-shirt on the surface where you will be dyeing it.
Wherever you want to make a design on the T-shirt, place a plastic cup underneath the shirt (which should be flat so that both layers of the shirt are stretched over the cup) and then loop a rubber band around the edge of the cup, going from the front of the T-shirt. This should end up making a flat, tight circle of the shirt fabric stretched over the cup opening. Do this to at least two places on the T-shirt so that you have at least two flat circles in which to draw.
Use the permanent markers to draw some colorful designs in each flat T-shirt circle that you made with the cups. Fill in at least two flat circles with your drawings.
Use the medicine dropper to drop a few drops of water onto the center of one of the flat circles that you drew in. What happens to the permanent marker ink when the water touches it?
Drop several more drops of water onto the same flat circle until it is thoroughly damp. Does the permanent marker ink change as the piece of fabric becomes damp?
Now use the medicine dropper to drop a few drops of isopropyl alcohol onto the center of one of the other flat circles that you drew in. What happens to the permanent marker ink when the alcohol touches it?
Drop several more drops of alcohol onto the same flat circle until it is thoroughly damp. Does the permanent marker ink change as the piece of fabric becomes damp with alcohol?
Compare the two flat circles. Which one looks better? Why do you think that might be?
(Tip: If you want to make one of the flat circles look better, try letting it dry—either naturally or with a hairdryer—and then adding drops of the other liquid—water or alcohol—which should be the liquid that gave you the best results.)
If you want to make more colorful designs on your T-shirt, let the first ones dry and then repeat the procedure on different parts of the shirt where you want some artwork, but this time just use the liquid (water or alcohol) that gave you the best results!
Extra: To more closely compare results between using water versus alcohol, make a symmetrical design in one of the flat T-shirt circles and treat one half with water and the other half with alcohol. How exactly does the one half of the circle look compared with the other half?
Extra: If you wash the T-shirt made in this activity, you will probably find that the colors fade. Can you figure out a way to keep the designs from fading?
Extra: Some markers are made using multiple dyes, and you can see these dyes using a chemistry technique called chromatography. Check out the links in the "More to explore" section to find out more about chromatography. Can you separate different dyes that are in permanent markers using chromatography?
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Observations and results
After water was added to the drawing, did the ink stay in place? Whereas after isopropyl alcohol was added, did the ink run and spread out, creating colorful artwork?
The ink used in permanent markers does not dissolve in water, meaning the ink is water insoluble. This is why when you added drops of water to the designs you made on the T-shirt, the ink should have pretty much stayed in place. Permanent marker ink, however, does dissolve in isopropyl alcohol, meaning the ink is soluble in it. Because of this, when you added drops of alcohol to the designs on the T-shirt, the ink should have spread out and ran along the fabric with the alcohol, creating a circle full of color. (This is similar to what happens when a drop of water lands on a piece of paper with something printed on it, and the ink starts to run on the paper, making the text blurry.) If you let the design that you put water drops on dry, dripping alcohol on it should make the ink run and create another colorful design on your T-shirt!
More to explore
Solutions as Special Mixtures, from Thunderbolt Kids
Paper Chromatography: Is Black Ink Really Black?, from Science Buddies
Sharpie Marker Tie Dye T-Shirts, from Pintriedit
Solubility Basics—What is Solubility, from Solubility of Things
Science Activities for All Ages!, from Science Buddies
This activity brought to you in partnership with Science Buddies