Unlock the secrets of corn starch: is it really non-newtonian?
What To Know
- The shear-thickening behavior of corn starch suspension can be attributed to the formation of a network of starch granules.
- Corn starch is used as a filler in sports equipment, such as footballs and baseballs, to enhance their responsiveness and durability.
- When corn starch suspension is subjected to high shear stress, the starch granules entangle and form a network, increasing viscosity and giving it a solid-like consistency.
The world of materials is vast and fascinating, with substances exhibiting diverse properties that often defy our expectations. One such substance is corn starch, a common kitchen staple that has captured the attention of scientists and enthusiasts alike due to its unusual behavior. This blog post delves into the question of whether corn starch is non-Newtonian, exploring its unique properties and the implications for its various applications.
What is a Non-Newtonian Fluid?
Before we delve into the nature of corn starch, it’s essential to understand the concept of non-Newtonian fluids. Newtonian fluids, such as water, exhibit a constant viscosity, meaning their resistance to flow remains the same regardless of the force applied. In contrast, non-Newtonian fluids display a viscosity that changes in response to applied force or shear stress.
Is Corn Starch Non-Newtonian?
Yes, corn starch is indeed a non-Newtonian fluid. When mixed with water to form a suspension, it exhibits shear-thickening behavior. This means that as the force applied to the suspension increases, its viscosity also increases.
Understanding Shear-Thickening Behavior
The shear-thickening behavior of corn starch suspension can be attributed to the formation of a network of starch granules. Under low shear stress, the granules remain dispersed and flow easily. However, as the shear stress increases, the granules collide with each other, causing them to entangle and form a network. This network restricts the movement of the granules, resulting in increased resistance to flow and, consequently, a higher viscosity.
Applications of Corn Starch’s Non-Newtonian Behavior
The non-Newtonian properties of corn starch have led to its use in various applications:
- Body Armor: Corn starch-based body armor has been developed, utilizing the shear-thickening behavior to absorb and disperse the impact of bullets.
- Sports Equipment: Corn starch is used as a filler in sports equipment, such as footballs and baseballs, to enhance their responsiveness and durability.
- Food Thickening: Corn starch is widely used as a thickening agent in cooking, adding texture and consistency to sauces, soups, and other dishes.
- Industrial Applications: Non-Newtonian fluids are employed in various industrial processes, including oil drilling, mining, and manufacturing, to control flow and prevent clogging.
Other Types of Non-Newtonian Fluids
Corn starch is just one example of a non-Newtonian fluid. Other examples include:
- Oobleck: A mixture of corn starch and water that exhibits both solid and liquid properties depending on the force applied.
- Silly Putty: A silicone-based polymer that flows like a liquid when stretched but bounces like a solid when dropped.
- Honey: A thick, viscous liquid that flows slowly and exhibits shear-thinning behavior, where viscosity decreases with increasing shear stress.
Summary: Unlocking the Potential of Non-Newtonian Fluids
The non-Newtonian nature of corn starch and other fluids opens up a world of possibilities for innovative applications. By understanding their unique properties, we can harness their potential to develop advanced materials, enhance existing technologies, and explore new frontiers in science and engineering.
Frequently Asked Questions
Q: Is corn starch a solid or a liquid?
A: Corn starch is a solid in its dry form but forms a non-Newtonian suspension when mixed with water.
Q: Why does corn starch become hard when squeezed?
A: When corn starch suspension is subjected to high shear stress, the starch granules entangle and form a network, increasing viscosity and giving it a solid-like consistency.
Q: Can corn starch be used to make slime?
A: Yes, corn starch can be used as a base for making slime, along with other ingredients like glue and water. The non-Newtonian properties of corn starch contribute to the slime’s unique texture and behavior.
Q: Is corn starch dangerous to consume?
A: Corn starch is generally safe to consume in small quantities as a food additive, but excessive consumption can lead to digestive issues.
Q: What other substances exhibit non-Newtonian behavior?
A: Many substances exhibit non-Newtonian behavior, including ketchup, toothpaste, quicksand, and certain types of paint.