What happens if you mix corn starch with glycerol?

When corn starch and glycerol are mixed, a viscoelastic fluid, commonly known as a non-Newtonian fluid, is formed. Upon exerting force or pressure (for example, through rapid stirring or squeezing), this fluid becomes highly viscous and behaves more like a solid. However, when the applied force or pressure is removed, it reverts to its original liquid-like state.

This behavior is a consequence of the interplay between corn starch particles and glycerol molecules. The corn starch particles have a tendency to form a dense network within the mixture. When force is applied, the network strengthens, causing the mixture to become stiffer and behave like a solid. When the force is removed, the network weakens, allowing the mixture to return to its liquid state.

This unique property makes the corn starch and glycerol mixture useful in various applications, including:

* Ooblek: This is a classic science experiment where a mixture of corn starch and water is formed. The mixture behaves like a solid when force is applied, such as when it is quickly squeezed, but it flows like a liquid when left undisturbed.

* Silly Putty: A widely popular children's toy, Silly Putty is made from a mixture of silicone polymers, mineral oil, and boric acid. It exhibits similar characteristics to the corn starch and glycerol mixture, transitioning between a solid-like and a liquid-like state based on the applied force.

* Thixotropic materials: These materials thicken upon application of force or agitation but become fluid again when the force is removed. Corn starch and glycerol can be used to create thixotropic substances that find uses in industries such as coatings, cosmetics, and food.

* Bioplastics: Corn starch and glycerol can also be combined to create bioplastics, which are biodegradable and environmentally friendly alternatives to traditional plastics.

In summary, when corn starch and glycerol are mixed, they form a non-Newtonian fluid that exhibits a unique transition between a solid-like and a liquid-like state depending on the applied force. This property makes the mixture suitable for various applications ranging from science experiments to industrial uses and toy production.