Thermochromatic pigment - is it magic?

Thermochromatic pigment is pretty spectacular. For lots of reasons. The first of which is, that it doesn’t exist. There is no such thing as Thermochromatic pigment. That is because the actual name of this product is Thermochromic pigment...as far as we can tell Sparkfun came up with the name and it has stuck. Anyway, this Thermochromic pigment is Leuco dyes, weak acids and salts microencapsulated in a polymer.

Thermochromatic pigment is pretty spectacular. For lots of reasons. The first of which is, that it doesn’t exist. There is no such thing as Thermochromatic pigment. That is because the actual name of this product is Thermochromic pigment...as far as we can tell Sparkfun came up with the name and it has stuck. Anyway, this Thermochromic pigment is Leuco dyes, weak acids and salts microencapsulated in a polymer.

So, how does it work? There's some basic science behind the way it works - the pigment contains a colorant, an organic acid, and a solvent. At lower temperatures the solvent remains in a solid state, keeping the colorant and acid in close proximity to each other and as a result, they reflect light and create colour. As the solvent warms, the colorant and the acid separate and there's no visible color. Now, Leuco dyes are dyes that change between 2 colours, one of which is white. The three things that can change the colour of different Leuco dyes are PH, light, and heat. The one we are working with is heat.

This stuff is really cool when put in different things. For now, the only thing I have tested is putting it in Playdough. And that is cool! The Playdough changes at 32-33°C to completely white. It is awesome. Playing with a small amount in your hand makes it go white in minutes, and then you can just watch it cool. Or, using the bottom of a mug of hot water/tea can make it white, then make it red with a mug of iced water.

Overall, the Thermochromic pigment is both amazing to watch, play with, and study. It is a scientific wonder which I definitely recommend to anyone who wants to make more interesting paint, glue, playdough, and just about anything that can be coloured with a pigment.

At Little Bird Electronics we carry this pigment in 4 colours,  Red, Blue, Black and Yellow