Thermochromic Mug
Warning!
Adult supervision: (choking hazards, liquids not for drinking, etc.)
Please read the procedure before beginning! After reading, please watch the video. Some activities require more time and cleanup than others. You also have the choice of performing these activities in a way that suits your needs.
Materials
- Plain Mug
- Clear Nail Polish
- 2 Paint Cups with Thermochromic Pigment
- Sharpie
- Using the Sharpie, draw a design on the mug that will be filled in with 2 colors of thermochromic paint.
- Open one of the tins containing thermochromic pigment, and pour in no more than half of the clear nail polish. Stir using the brush until the consistency is smooth.
- Paint all parts of the design that will be filled in with the color mixed in step 2.
- Repeat steps 2 and 3 with the other pigment color.
- Set the mug aside to dry.
- Warm it up using your hands or by filling it with a hot liquid, and watch as the colors change. What happens if cold liquid is added instead?
- Be very careful when cleaning the mug—hand wash the inside only while gently spot cleaning the outside or use only as a decorative mug.
- Optional: Have an adult cover your design with a food-grade waterproof epoxy so that the mug can be easily washed and reused for warm drinks.
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Science Behind it!
Thermochromic pigment is inserted into paints to change the color of the paint based on changing the temperature.
The word thermo means heat or hot. Think of the word thermometer. A thermometer is a measuring device used to determine how cold or hot something is.
The word chromic means the changing of colors. We see colors in the visible spectrum part of the world. A red apple appears red because the apple reflects red in the sunlight and absorbs every other color. The electromagnetic spectrum is a range of all of the waves of light. But this experiment also involves properties of chemistry.
Chemistry tells us that atoms share electrons, there is a bond in-between them. Heat excites the electrons, breaking the bond between the atom and the electron. When the bond breaks, it changes the molecule into a different color. What color does your mug turn into when those bonds break? When the mug returns to room temperature, the bond forms again and changes back into the original color.
Can you think of a reason that this thermochromic paint would be helpful? What other materials can you paint? Experiment to see if thermochromic paint can be changed by solids or gases that are hold or cold, not just for liquids.