Slime has become a popular trend, but have you ever wondered about the chemistry that goes into it? Slime is fascinating because it exhibits both liquid and solid properties. When you apply force, like stretching or pulling it, it behaves like a solid. When you release the force, it behaves like a liquid. Slime is a non-Newtonian fluid, which means its viscosity can change depending on the amount of force applied to it.

The main ingredient in most slime recipes is a polymer called polyvinyl alcohol (PVA). When PVA is mixed with a solution like borax, also known as sodium borate, it undergoes a chemical reaction called cross-linking. When borax is dissolved in water, it releases borate ions. These ions interact with the hydroxyl groups in the polymer chains, leading to cross-linking. As the cross-links form, the slime transforms from a liquid like state to a more solid and stretchy substance.

The cross-linking process affects the behavior of the slime. When you apply force, like stretching or pulling it, the cross-linked polymer chains resist movement. This gives the slime a more solid-like texture. When you release the force, the cross-links break allowing the slime to flow like a liquid. It’s fascinating how a few simple chemical reactions can transform everyday ingredients into a substance like slime.

Source: The Science of Slime!