Unlock the secrets of non-newtonian fluids: is corn starch the key?

In the realm of science, the properties of materials often captivate our curiosity. Among these, the non-Newtonian behavior of corn starch stands out as a fascinating phenomenon. But what exactly is a non-Newtonian fluid, and how does corn starch exhibit this unique characteristic?

Understanding Non-Newtonian Fluids

Non-Newtonian fluids are substances that deviate from the typical Newtonian behavior of liquids. In a Newtonian fluid, the viscosity remains constant regardless of the applied force or shear rate. However, in a non-Newtonian fluid, the viscosity changes with the applied force.

Corn Starch: A Dilatant Non-Newtonian Fluid

Corn starch is a dilatant non-Newtonian fluid, which means it thickens when subjected to force. When a small force is applied, the corn starch particles flow freely, exhibiting a low viscosity. However, as the force increases, the particles become tightly packed, leading to a rapid increase in viscosity.

Demonstrating Non-Newtonian Behavior

The non-Newtonian behavior of corn starch can be easily demonstrated through simple experiments. One classic example is the “Oobleck” experiment, where a mixture of corn starch and water is created. When the mixture is gently stirred, it behaves like a liquid. However, when a sudden force is applied, such as by hitting it with a hammer or fist, it solidifies like a solid.

Applications of Corn Starch’s Non-Newtonian Properties

The unique properties of corn starch have led to its use in various applications, including:

• Body armor: Corn starch-based materials have been developed for use in body armor due to their ability to absorb and dissipate impact energy.
• Industrial thickeners: Corn starch is used as a thickener in various industries, such as food, cosmetics, and pharmaceuticals.
• Shock absorbers: Corn starch-based materials can be used as shock absorbers due to their ability to absorb and release energy.
• Self-healing materials: Corn starch-based composites have been designed to exhibit self-healing properties, enabling them to repair themselves after damage.

Other Non-Newtonian Fluids

Corn starch is not the only substance that exhibits non-Newtonian behavior. Other examples include:

• Honey: Honey is a shear-thinning non-Newtonian fluid, meaning it becomes less viscous as the applied force increases.
• Blood: Blood is a non-Newtonian fluid that exhibits both shear-thinning and shear-thickening properties depending on the flow conditions.
• Toothpaste: Toothpaste is a shear-thickening non-Newtonian fluid, becoming more viscous when squeezed out of the tube.

Recommendations: Corn Starch’s Versatility

The non-Newtonian behavior of corn starch has opened up a wide range of applications, from body armor to self-healing materials. Its unique properties continue to inspire scientists and engineers to explore new and innovative uses for this versatile substance.

What You Need to Know

Q: What other substances exhibit non-Newtonian behavior?
A: Honey, blood, toothpaste, and slime are examples of other non-Newtonian fluids.

Q: Why does corn starch thicken when force is applied?
A: The corn starch particles become tightly packed under force, leading to an increase in viscosity.

Q: What is the difference between a Newtonian and a non-Newtonian fluid?
A: In a Newtonian fluid, viscosity remains constant, while in a non-Newtonian fluid, viscosity changes with the applied force.

Q: Can corn starch be used to make body armor?
A: Yes, corn starch-based materials have been developed for use in body armor due to their ability to absorb and dissipate impact energy.

Q: What is the “Oobleck” experiment?
A: The “Oobleck” experiment demonstrates the non-Newtonian behavior of corn starch by creating a mixture that behaves like a liquid when stirred gently but solidifies when force is applied.