Researchers at Drexel University have discovered that certain viscous liquids can snap apart like solids when stretched with sufficient force. The finding, detailed in a study published in Physical Review Letters, challenges traditional views of fluid dynamics by linking the behavior to viscosity rather than elasticity. This phenomenon was observed in simple liquids such as tar-like hydrocarbons and styrene oligomer.
Thamires Lima, an assistant research professor at Drexel's College of Engineering, and Nicolas Alvarez, a professor there, led the research in collaboration with ExxonMobil Technology & Engineering Company. During extensional rheology tests, the team stretched tar-like hydrocarbon blends and noticed they fractured abruptly at a critical stress of 2 megapascals, producing a loud snapping noise captured on high-speed camera. Lima described the moment: 'The fracture caused a very loud snapping noise that actually startled me. I thought at first the machine had broken, but soon realized that the noise came from the stretching fluid.'
