Thermochromic slime

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.

Equip­ment

• PVA glue;
• con­tact lens so­lu­tion;
• bak­ing soda so­lu­tion;
• ther­mochromic pig­ment;
• re­seal­able bag;
• glass bowls.

Step-by-step in­struc­tions

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!

Process de­scrip­tion

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!