So remember back when we wrote about superhydrophobicity? Well we just ran across another interesting use of the coating that repels water: Teapots. Apparently some scientists have figured out how to stop them from dripping all over the place. Here’s the explanation from the physics arXiv blog:
Now Cyril Duez at the University of Lyon in France and a few amis, have identified the single factor at the heart of the problem and shown how to tackle it. They say that the culprit is a “hydro-capillary” effect that keeps the liquid in contact with the material as it leaves the lip. The previously identified factors all determine the strength of this hydro-cappillary effect.
So how to overcome it? There are two ways say Duez and co. The first is to make the lip as thin as possible. That’s why teapots with spouts made from thin metal are less likely to dribble.
The second is to coat the lip with the latest generation of superhydrophobic materials which strongly repel water. Duez and co show how this stops dribbling at a stroke. “Superhydrophobic surfaces fully avoid dripping, and thus beat the “teapot effect”,” they say.
Gotta love science solving everyday problems. [Link via Sciblogs]