Introducing … bubble-free boiling?
This is Sandra Tsing Loh with the Loh Down on Science.
Imagine heating a pot of water. As it starts to boil, molecules near the heat source change into vapor, forming microscopic bubbles. These eventually merge into bigger ones, rise, and--poof!--burst into the air at the surface. A roiling boil!
Not anymore. Meet mechanical engineers from Northwestern University.
They slathered a mixture of plastic and silica over the inside of a steel cup, then baked it. The result? A coating slicker than Teflon but microscopically rougher than rock candy. Liquids slip and slide over it. But vapor? Sticks like Velcro.
Now, if you add liquid to the cup and turn up the heat, vapor carpets nearly the cup's entire surface. Because all the droplets are held in place, they never merge into full-blown bubbles. As for the few vapor-less areas? Liquid at the ultra repellant cup surface can't get a foothold long enough to heat up into an explosively dangerous fizz. Voila! Bubble-less boiling.
Next up? Suppressing those bubbles in public pools. Science can only try!
The Loh Down on Science is produced by LDOS Media Lab, with 89.3 KPCC Pasadena, California. And made possible by the generous support of the Gordon and Betty Moore Foundation.