Published on November 13th, 2010 | by Tina Casey4
Nano-Engineering Could Spell the End of Road Salt
November 13th, 2010 by Tina Casey
Road salt, which keeps our roads and highways passable in winter while poisoning nearby environments, leaching into streams and lakes, and doing nasty things to the metal parts of our cars, may be on its way out. Engineers at Harvard University are developing new nanostructured materials that can prevent surfaces from icing by repelling water before it has a chance to freeze. Along with eliminating the direct impacts of salt on the environment, the new materials would also cut carbon emissions related to shipping and spreading road salt.
New Nano-Surfaces that Prevent Ice Buildup
The engineers based their approach on the fact that ice buildup is a dynamic process that occurs over time, and they modeled their materials on bristles and other repellent surfaces found in nature. High speed video playback of water droplets hitting the surfaces revealed the forces at play in ice prevention. When water hits a smooth surface, it spreads out, clings and freezes. When it hits a repellent surface, it acts like a rubber ball in a cartoon: it flattens out on impact but then springs back to its round shape and bounces away.
The Next Step for Environmentally Friendly De-Icing
The engineers note that nano-structured materials could be used as coatings for airplanes and other objects, as well as for road surfaces. The labwork is promising and real-world testing has begun. It’s also possible that the new materials could be used in tandem with other sustainable de-icing technologies on the horizon, such as solar energy harvested from road surfaces.
Image: Road salt by benimoto on flickr.com