Science

Nano-particle coating prevents ice buildup on roads and power lines

Roads covered in ice can be difficult and dangerous to drive on
Roads covered in ice can be difficult and dangerous to drive on
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The surface on the left coated in the superhydrophobic coating is devoid of ice, while the uncoated surface is almost completely covered
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The surface on the left coated in the superhydrophobic coating is devoid of ice, while the uncoated surface is almost completely covered
Roads covered in ice can be difficult and dangerous to drive on (Photo: Becca8383 via Wikipedia Commons)
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Roads covered in ice can be difficult and dangerous to drive on (Photo: Becca8383 via Wikipedia Commons)
Roads covered in ice can be difficult and dangerous to drive on
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Roads covered in ice can be difficult and dangerous to drive on

Like most things, ice can be a blessing or a burden depending on the circumstances. It’s perfect crushed in a drink on a hot summer’s day, but can wreak havoc when it collects on roads, power lines and aircraft in freezing temperatures. A University of Pittsburgh-led team has found a way to reduce these dangers by developing a nanoparticle-based coating that can be easily applied to impede the buildup of ice on solid surfaces.

The superhydrophobic coating developed by the researchers mimics the rutted surface of lotus leaves by creating microscopic ridges that reduce the surface area to which water can adhere. Although the surface of the lotus leaf has already served as the inspiration for self-cleaning plastics, more efficient solar cell surfaces, and a special coating for spaceflight equipment, because ice behaves differently than water, relying on the same method used to repulse water used in these examples couldn’t be readily applied to ice.

To ward off ice buildup the team found that superhydrophobic coatings must be specifically formulated. Di Gao, a chemical and petroleum engineering professor in Pittsburgh University's Swanson School of Engineering, and his team created different batches made of a silicone resin-solution combined with nanoparticles of silica ranging in size from 20 nanometers to 20 micrometers. They applied each variant to aluminum plates then exposed the plates to supercooled water (-20 degrees Celsius) to simulate freezing rain.

They found that, although each compound containing silica bits of 10-or-fewer micrometers deflected water, only those with silica pieces less than 50 nanometers in size completely prevented icing. The minute surface area of the smaller fragments means they make minimal contact with the water. Instead, the water mostly touches the air pockets between the particles and falls away without freezing. Though not all superhydrophobic coatings follow the Pitt recipe, the researchers conclude that every type will have a different particle-scale for repelling ice than for repelling water.

To test its real world potential Gao tested the coating with 50-nanometer particles outdoors in freezing rain. He painted one side of an aluminum plate and left the other side untreated. As can be seen in the video below the treated side had very little ice, while the untreated side was completely covered. He produced similar results on a commercial satellite dish where the glossed half of the dish had no ice and the other half was encrusted.

The research team’s findings are detailed in the paper, Anti-Icing Superhydrophobic Coatings, which appears in Langmuir.

Anti-Icing Superhydrophobic Coating

2 comments
Mitchell Rognerud
Looking closely at this picture, and having grown up in the Nation's Icebox, I have to point out what appears to be shoreline. Comined with the general flatness of the landscape, the overall appearance of the roadway and the snowmobile tracks, I'd have to say this picture is of an ice road. Yes, this is a road that is plowed on a frozen body of water. If that is the case, then it makes NO SENSE when used with your cool story. When the ice IS the road, you probably want to keep it frozen. :) Thanks for listening! <i>Eds note - good point Mitchell, thanks for keeping us on our toes. We've found a more suitable pic.</i>
Gargamoth
nano coating looks like a great idea, but while making sure raods don't ice up, will cars also lose some traction or will it have zero effect on tires?