Sam: Welcome to the Sound of Science on WNIJ. I’m Sam from NIU STEM Outreach.
Nicole: and I’m Nicole James from NIU Department of Chemistry and Biochemistry. I researched non-Newtonian fluids like Oobleck for my PhD.
Sam: Oobleck is a cornstarch and water mixture that acts kinda funny. It’s runny and goopy until you apply a sudden force, then it feels solid. It’s one of many non-Newtonian fluids.
Nicole: Non-Newtonian fluids are fluids that change their viscosity based on how they’re treated. They’re called this because they don’t follow conventional Newtonian fluid dynamics. While Oobleck is one of the most famous—and one of the most extreme, it’s certainly not the only one in our lives. There are lots of things that ‘thicken’ or ‘thin’ as you stir them.
Sam: These fluids are more common than you might think. Take a look in your fridge and you’ll probably see two: Ketchup and mayonnaise. It’s hard to get them out of their bottles, but they spread very easily. They ‘thin out’ when force is applied.
Nicole: A lot of every-day fluids are engineered to be non-Newtonian. Imagine trying to paint a wall with really thin paint. It would drip and smear and make an awful mess. Also imagine trying to mix up a really thick paint. It wouldn’t mix full or it would take forever. Latex paints are designed to be really thick at rest, say when the paint is already on the wall, so it doesn’t drip. However, when you’re stirring it or brushing it on, it’s thin so that its easy to stir and flows smoothly on the wall.
Sam: While a slew of examples is neat, you might be wondering why knowing about non-Newtonian fluids are important at all. With synthesized and engineered non-Newtonian fluids, we can find practical applications in healthcare and security.
Nicole: Imagine clothing or gloves that are puncture-resistant because there is a thin layer of non-Newtonian material that turns stiff or solid with an increased force. Prison guards could be that much safer from stab wounds. Doctors and nurses wearing special gloves would be protected from infections and accidental needle-sticks.
Sam: Foods, home décor, and healthcare! Non-Newtonian fluids go beyond goop for kids! We hope we got your thoughts flowing here on The Sound of Science on WNIJ.
Nicole: Where you learn something new every day.