Canadian Researchers Develop Permanent Anti-Fog Coating

cylonlover writes "Tired of your glasses fogging up on cold days, or of having to spit in your dive mask before putting it on? Those hassles may become a thing of the past, as researchers from Quebec City's Université Laval have developed what they claim is the world's first permanent anti-fog coating. Just one application is said to work indefinitely on eyeglasses, windshields, camera lenses, or any other transparent glass or plastic surface."

Comments

Re:Uhm...

[AliasMarlowe]

From TFA:

The actual anti-fog coating itself is composed of polyvinyl alcohol, which is a hydrophilic compound that causes the individual droplets of condensation to disperse

Unless I'm waaaay off, I think they mean hydrophobic, as in "it doesn not bond with water".

Um, you are, indeed, way off.

A hydrophobic coating would cause condensation to coalesce into droplets minimizing contact area between the condensate and the surface. In other words, it would fog the surface: due to refraction and internal reflection, small water droplets in air are essentially opaque while large droplets act as distorting lenses.

A hydrophilic coating, on the other hand, causes the condensation to form a continuous film maximizing contact between the condensate and the surface. This would remain transparent and would not greatly distort images viewed through it unless the amount of condensate was very large.

Problem is dirt

[snsh]

The difficulty with anti-fog surfaces is keeping it clean. For glasses/sunglasses this isn't so hard since you can easily clean the lenses in a sink with soap. For the inside surface of a car windshield it's a totally different story. In most cars the inside windshield fogs up mostly because it's dirty. The windshield glass itself is hydrophilic enough that it wouldn't be fogging up a lot, but there's a layer of goop on the glass that's hydrophobic which fogs up easily. The goop resembles a mix of everything you ever smell inside the car (new car smell, old car smell, exhaust fumes, McDonalds, Starbucks, bad breath). If you try super-thoroughly cleaning one half the windshield, and not clean the other half, you'll get an idea of how bad it is.

Re:Problem is dirt

[velinion]

1/4 cup vinegar, 1/2 teaspoon liquid soap or detergent, and 2 cups of water in a spray bottle.

Spray on window, and rub vigorously with terry cloth. Works wonders.

Re:Problem is dirt

[snsh]

I take a bottle of standard glass cleaner (ammonia + surfactant) and 5% alcohol and 5% acetone. On a warm day in the shade with the doors open, wear gloves, hold your breath, spray on a crumpled newspaper and use that to clean.

Re:sure...

[Lumpy]

http://www.zennioptical.com/

I get decent quality stuff on the midgrade lenses for the price the optometrist pays.. whenever I get a new set of glasses, I order 3 more sets from this place.

Nothing like having 2 sets of spares and one set of "grunge glasses" to use when getting sweaty or really dirty to keep the expensive nice ones looking new.