Engineers at Northwestern University in the United States have developed a new strategy to prevent ice formation before it starts.
In the new research, scientists discovered that adjusting the texture of any surface and adding a thin layer of graphene oxide prevents 100% frost formation on surfaces for a week or more.
The result is, according to , 1000 times longer lasting than current state-of-the-art antifreeze surfaces.
“A unwanted frost accumulation it is a major concern in the industrial, residential and government sectors”, highlighted expert Kyoo-Chul Kenneth Park. “It is critical to develop effective anti-icing techniques for long periods of time in extreme environmental conditions. It is also necessary to develop antifreeze methods that are easy to manufacture and implement.”
Researchers have created an antifreeze technique hybrid able to prevent frost from forming for weeks. In addition to being durable, it is scalable and easily manufactured through 3D printing.
Four years ago, Park and his team discovered that adding millimeter-scale textures to a surface reduced ice formation by up to 80%. Published on Proceedings of the National Academy of Sciences, was inspired by the wavy geometry of the leaves.
“There is more frost formation in the convex regions of a leaf,” he explained. “In the concave regions (the ribs), we see much less frost. There was no explanation for the formation of these patterns, until we discovered that it is the geometry — and not the material — that controls it.”
After several computer simulations, the researchers found that condensation increases at the peaks and is lower in the valleys of wavy surfaces. The small amount of water condensed in the valleys evaporates, resulting in a frost-free area.
While in the previous study the team developed a surface with millimeter-scale peaks and valleys with small angles between them, in this new study the scientists added graphene oxide in flat valleys, which reduced ice formation by 100%.
The new surface comprises small protrusions, with a peak-to-peak distance of 5 millimeters, and a thin layer of graphene oxide lining the valleys between them.
“Graphene oxide attracts water vapor and confines water molecules within its structure,” explained Park. “The graphene oxide layer acts as a container to prevent water vapor from freezing. When we combined graphene oxide with the macrotexture surface, we found that it resists frost for long periods at high supersaturation.”
While superhydrophobic (water-repellent) and lubricant-infused surfaces had frost resistance rates of 5 to 36% over 5 hours, this new surface resisted 100% of freezing formation for 160 hours.
The was published in Science Advances.
