When a coffee mug changes from black to white upon pouring a hot beverage, you are fascinated by it. When it reveals a message or photo, it amazes you more. The thought that crosses your mind at that second is, “How does it do that?”
If you have come here searching for the science behind these color-changing mugs, you have come to the right place. Without further ado, let’s reveal the magic.
Heat-Sensitive Paint
We paint our custom coffee mugs with a heat-sensitive paint to convert them into heat-sensitive mugs. You can customize the magic mugs with a message, picture, or both. You’ll also find manufacturers applying heat-sensitive paint to kettles, baby bottles, car engines, and other items.
When the coffee mug cools down, the mug turns black again. If you have witnessed the transition before your eyes, you’re already aware of how fascinating it is to watch the coffee mug change color and reveal the hidden image. Heat-changing paint is just one part of the formula. The other part of the formula is thermochromism.
Thermochromism
Thermochromism is the color-changing ability of some materials when an increase in temperature occurs. Thermochromism falls under the category of chromism, which causes the color-changing phenomenon. As you know, it's reversible, which means it can revert to its starting color. Mood rings are a classic example of this process.
The fluctuation in body temperature influences the mood ring’s color. Things have progressed with time, and from color-changing mood rings, we have come to color-changing mugs.
The Magical Connection Between Thermochromism and Heat-Sensitive Mugs
Thermochromism is what makes our personalized ceramic coffee mugs change color. Think of it has a key ingredient. It gives your coffee mug the ability to change from black to white. Most people refer to thermochromism as heat-sensitive paint, as it’s easier to remember when and if someone asks about the magical process of color changing mugs.
Heat-Sensitive Paint: The Process
Heat-sensitive paint or thermochromic paint contains pigments that change the coffee mug’s color when a hot beverage is poured into it. The two primary types of pigments are leuco dyes and thermochromatic liquid crystals.
Leuco Dyes and Thermochromatic Liquid Crystals
Manufacturers use liquid crystals to perform high-precision tasks, especially those where you need to track the smallest fluctuation in temperature. For this reason, manufacturers don’t use liquid crystals to create regular objects, such as custom coffee mugs and baby bottles.
For these objects, you need to know the approximate temperature of the beverage being too cold or too hot to the touch. Liquid crystals are out of the picture since you can’t use them to create heat-changing mugs. Hence, leuco dyes take center stage.
Thermochromic dyes contain leuco dyes combined with other chemicals to produce that color-changing effect that fascinates you and others. When you pour a hot beverage in a custom photo mug with color-changing properties, the leuco dyes change from black to white.
Micro-capsules containing this dye are available. Apart from color changing mugs, another example of this is hypercolor clothes. You may not be familiar with hypercolor clothes, which change color based on a change in temperature, as they’re no longer in fashion. The entire process about how the coffee mug goes from black to white is interesting.
The Color-Changing Process
You combine the dye with salt crystals, which can either have an extremely high pH level or an extremely low pH level. The environment’s pH level changes the color of the paint. An increase in temperature causes a chemical reaction, resulting in the salt crystals mixing in with the dye. This is how the color of your custom photo mug changes.
When you drink from the coffee mug or let it cool down, it gradually returns to its original color, which is black, thus covering the message or image.
Color-changing mugs are unique gifts to give or get from someone. You can give heat-sensitive mugs to people on special days and occasions. You can’t add anything to the black color, only on the white color. The hot beverage will change the color, and it’ll return to black once the coffee mug cools down.
Do you want to buy color-changing mugs? If you want to buy a heat-changing mug, you can buy it here. You can get it for yourself or a loved one with a customized message and picture.