Title: Scientists Uncover Molecular Secrets of Non-Newtonian Fluid “Oobleck”
Oobleck, a shear-thickening non-Newtonian fluid, has long been a favorite kitchen science experiment due to its fascinating behavior as either a liquid or a solid depending on the amount of stress applied. But scientists at the University of Chicago have delved into the molecular level of this simple substance, uncovering the complex physics principles behind its behavior.
The study, published in the Proceedings of the National Academy of Sciences, used dense suspensions of piezoelectric nanoparticles to measure what happens at the molecular level when oobleck transitions from liquid to solid behavior. This sheds light on the surprising nuances and complexity of the underlying physics principles of this common kitchen experiment.
Non-Newtonian fluids, like oobleck, exhibit viscosity changes in response to an applied strain or shearing force, straddling the boundary between liquid and solid behavior. This behavior is different from ideal fluids, where the viscosity largely depends on temperature and pressure.
Ketchup, yogurt, gravy, mud, pudding, and thickened pie fillings are also examples of shear-thickening non-Newtonian fluids, whose viscosity increases with the application of force.
In 2019, MIT researchers developed a mathematical model to predict how oobleck transitions from liquid to solid and back again under different conditions, further shedding light on the physics behind this unique substance. This model adapted the working model for wet sand, a granular material, but found that the physics at small size scales are markedly different.
The new study provides a deeper understanding of the molecular secrets of non-Newtonian fluids like oobleck, unraveling the complex physics principles behind their fascinating behavior.
In conclusion, the study highlights the surprising complexity of everyday substances and the exciting potential for developing new materials and applications based on a deeper understanding of their underlying physics.