When a drop settles gently against a pool of the same liquid, it will coalesce. The process is not always a complete one, though; sometimes a smaller droplet breaks away Keep reading
Tag: surfactant
Lasers and Soap Films
Soap films are a great system for visualizing fluid flows. Researchers use them to look at flags, fish schooling and drafting, and even wind turbines. In this work, researchers explore Keep reading
Surfactants and Waves
In the ocean, waves often curl over and trap air, becoming plunging breakers. How do surfactants like soap or oil affect this process? That’s the question behind this video, where Keep reading
Ink-Based Propulsion
In this video, Steve Mould explores an interesting phenomenon: propulsion via ballpoint pen ink. Placing ink on one side of a leaf or piece of paper turns it into a Keep reading
Taking A Turn
Water droplets immersed in a mixture of oil and surfactants will move about, propelled by the Marangoni effect. Surfactant molecules congregate along the interface between the water and oil, but Keep reading
Stabilizing Foams
Bubbles in a pure liquid don’t last long, but with added surfactants or multiple miscible liquids, bubbles can form long-lasting foams. In soapy foams, surfactants provide the surface tension gradients Keep reading
Oil Drops and Filter Feeders
Natural oils provide critical nutrients to filter feeders like zooplankton and barnacles. These creatures capture oil droplets on bristle-like appendages such as cilia and setae. But this droplet-catching turns into Keep reading
Polygonal Droplets
Spheres are a special shape; they provide the smallest possible surface area necessary to contain a given volume. And since surface tension tries to minimize surface energy by reducing the Keep reading
Exploding a Drop
Leidenfrost drops levitate over a hot substrate on a thin layer of their own vapor, constantly replenished as the drop evaporates. For the most part, previous studies have focused on Keep reading
Entrained
When an object hits water whether it draws air in with it depends on its shape, impact speed, and surface characteristics. In this experiment, though, there’s a bit of a Keep reading