• CORRECTION: This story was updated on July 12, 2012. The sentence that previously read, “Today’s defrosting techniques involve either corrosive chemicals or periodic heating, which consumes power,” was updated to read, “Today’s defrosting techniques involve either environmentally harmful chemicals or periodic heating, which consumes power.”

Latest News
Web Date: June 15, 2012

Slippery Coating Keeps Metals Frost-Free

Materials Science: Oil-infused textured surface could prevent ice buildup on airplane wings and refrigerator coils
Department: Science & Technology
News Channels: Materials SCENE, Nano SCENE
Keywords: ice-free metal, frost-free, slippery liquid-infused porous surfaces, SLIPS
No Ice
An aluminum surface coated with an oil-infused nanostructured layer known as SLIPS (black) stays free of frost at a few degrees below 0 ºC, while untreated aluminum ices up (white). The coated aluminum surface is about 3 cm wide.
Credit: ACS Nano
Photograph of aluminum surfaces with and without frost.
 
No Ice
An aluminum surface coated with an oil-infused nanostructured layer known as SLIPS (black) stays free of frost at a few degrees below 0 ºC, while untreated aluminum ices up (white). The coated aluminum surface is about 3 cm wide.
Credit: ACS Nano

Researchers have found an easy way to encrust metals with a material that is super slippery and repels water (ACS Nano, DOI: 10.1021/nn302310q). By preventing water droplets from sticking to surfaces and then freezing, the coating could keep airplane wings, wind turbines, and refrigerator coils frost-free.

Today’s defrosting techniques involve either environmentally harmful chemicals or periodic heating, which consumes power. Meanwhile, most water-repellent coatings fail in high humidity. These coatings often have nanoscale features that cause water to bead up and bounce off. But in high-humidity, low temperature conditions, such as those on a snowy day, condensation builds up inside the nanostructures and can freeze.

Joanna Aizenberg and her colleagues at Harvard University previously had developed flat, ultrasmooth water-repellent coatings called slippery liquid-infused porous surfaces, or SLIPS (Nature, DOI: 10.1038/nature10447). These coatings consist of a porous network of polymer nanofibers infused with a lubricant.

The team thought a SLIPS could prevent frost buildup on metal surfaces, in addition to plastic, which they had coated in their previous work. To test the coatings on aluminum refrigerator coils, the researchers first deposited a bumpy polypyrrole layer on the metal. They then added DuPont’s lubricating Krytox oil to the layer and allowed it to infuse into the polymer matrix.

Unlike untreated aluminum, the treated metal surface stayed completely ice-free down to -4 ºC. Ice formed at lower temperatures, but it didn’t adhere well: The researchers could shake or melt it off in seconds.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Joc (Tue Dec 17 07:44:33 EST 2013)
So, to keep aluminum fins of a heat pump frost free in winter, thus preventing defrosts, that would be the solution? Permanent?
Is it already in production? And if it is, where to buy it?

Can't wait!!! :)
squeek (Thu Jan 09 10:49:54 EST 2014)
I can't imagine the use of oily substance on the fins of a vapouriser of a heat pump or AC. The fan blows air and pollutants through the fins of the radiator and if the fins were treated with an oily substance the pollution would stick. With increased popularity of cheap wood burning heating systems in my area this would be a disaster for my heat pump...
Or am I wrong?
KDAR (Wed Jan 04 08:06:12 EST 2017)
I seek, an extremely slippery chemical solution miscible or not with water, which eliminates the friction between glass and metal (stainless ... example)
THANK YOU
Kenneth C. Hill (Thu Mar 16 23:45:00 EDT 2017)
I am seeking such a substance to coat stainless steel and aluminum broadcast antennae so the antennae will not cause transmitter distress in cold weather due to ice build-up. Is this available? If so, I have an antennae installation that needs the coating.
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