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
Tag: surfactant
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
What Keeps a Foam Intact
Beer, soda, soap, meringue – foams are everywhere in our lives. But have you ever wondered why some foams disappear so quickly while whipped egg whites stick around? That’s the Keep reading
Swimming Microdroplets
Simple systems can sometimes have surprisingly complex behaviors. In this video, the Lutetium Project outlines a scheme for swimming microdroplets. Most of the droplets shown are just water, but they’re Keep reading
Solving Mazes
Earlier this fall, I attempted my first corn maze. It didn’t work out very well. Early on I unknowingly cut through an area meant to be impassable and thus ended Keep reading
Detergency
Have you ever wondered just how detergents are able to get grease and oil off a surface? This simple example demonstrates one method. In the top image, a drop of Keep reading