Thermochromic Materials

Thermochromic materials are substances that change color with temperature. They are used in novelty items, clothing, toys, and scientific demonstrations, allowing students to see a physical property that responds directly to heat.

1. Obtain a commercially available thermochromic item, such as mood rings, color-changing spoons, mugs, or thermochromic pigments.
2. Warm the object by holding it in your hand, placing it in warm water, or shining a lamp on it.
3. Observe the color change as the temperature shifts.
4. Allow the item to cool back to room temperature and watch the color return.

INTERESTING MATERIALS: Thermochromic Materials - Gabriele Mogni:

Color Changing Thermochromic Slime (Chemistry) - BeardedScienceGuy:

Smart Textiles - Thermochromic paint - Cheryl Sleboda Whited:

• Use different thermochromic products (mugs, slime, nail polish, stickers, fabrics).
• Compare how quickly items change color under different heat sources (hand warmth, hot water, hair dryer).
• Test durability by repeatedly heating and cooling the material.

• Use only safe, consumer-grade thermochromic products in the classroom.
• If using warm water, ensure it is not hot enough to cause burns.
• Do not overheat items (e.g., avoid direct flames).

• Why do thermochromic materials change color with temperature? (They contain pigments or liquid crystals that rearrange as temperature changes, altering light reflection.)
• Are these color changes physical or chemical changes? (They are physical changes, since the substance is not permanently altered.)
• Where might thermochromic materials be useful in everyday life? (In thermometers, baby spoons, battery testers, clothing, and safety indicators.)
• How do liquid-crystal thermochromics differ from pigment-based ones? (Liquid crystals shift structure with temperature, while pigments change molecular arrangement to absorb different wavelengths of light.)