“Nanocoating” could eliminate window fogging
I’m always skeptical whenever I read something about “nanotechnology.” The actual definition of “nanotechnology” is
the science and technology of building electronic circuits and devices from single atoms and molecules.
So when I read headlines like “Nanocoating could eliminate foggy windows and lenses” I immediately become skeptical, even when it’s an institution like MIT turning out the press release. The word “nanotechnology” is some sort of magnet for public attention, particularly among the geek crowd that is usually misused, often by people that should know better.
Anyway my mini-rant aside, researchers at MIT have developed a coating of “silica nanoparticles.” It’s not nanotechnology (save that it’s the right molecular size), but it is a fancy coating that will prevent windows from fogging. What’s special about this new coating is that it doesn’t have the shortcomings that other fogging solutions have: it doesn’t require UV light to function, nor does its effectiveness decrease over time. The approach to the fogging problem is pretty unique:
When fogging occurs, thousands of tiny water droplets condense on glass and other surfaces. The droplets scatter light in random patterns, causing the surfaces to become translucent or foggy. This often occurs when a cold surface suddenly comes into contact with warm, moist air.
The new coating prevents this process from occurring, primarily through its super-hydrophilic, or water-loving, nature, Rubner says. The nanoparticles in the coating strongly attract the water droplets and force them to form much smaller contact angles with the surface. As a result, the droplets flatten and merge into a uniform, transparent sheet rather than forming countless individual light-scattering spheres. “The coating basically causes water that hits the surfaces to develop a sustained sheeting effect, and that prevents fogging,” Rubner says.
I think drivers everywhere would love something like this, provided it doesn’t cost an arm and a leg. (I know I would.) Two auto manufacturers are already interested in the technology, as is the US military.
Update: Kudos to New Scientist for not using any form of the word “nanotechnology” in their coverage.
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the definition of nanotech all depends on who you ask…
nanotechnology
n : the branch of engineering that deals with things smaller than 100 nanometers (especially with the manipulation of individual molecules)
Source: WordNet ® 2.0, © 2003 Princeton University
Comment by nimai — August 29, 2005 @ 7:31 pm