Stretch the slime to make it change colors!
Warning! Only under adult supervision.
- PVA glue;
- contact lens solution;
- baking soda solution;
- thermochromic pigment;
- resealable bag;
- glass bowls.
Pour some PVA glue into a bowl and add a thermochromic pigment. In another bowl, combine a solution of baking soda with some contact lens solution. Pour the glue into the resulting mixture – it thickens instantly. And if you knead it with your hands, then it will begin to stretch and change colors!
PVA glue contains long molecules of polyvinyl alcohol, while contact lens solution contains a small quantity of boric acid. Under the influence of the baking soda, the boric acid binds the polyvinyl alcohol molecules together with weak chemical bonds. As a result, the mixture thickens and turns into slime! The thermochromic pigment, meanwhile, changes colors when the temperature rises. As you mold the slime, the heat from your hands causes it to change colors! Store the slime in a resealable bag in order to keep it for as long as possible.
Amazing and safe experiments await you in the MEL Chemistry subscription!