At the surface of frozen water, even at temperatures below 0 °C, ice’s hexagonal structure breaks down and forms a liquid-like layer that lubricates the surface, allowing figure skaters to spin and glide. Inspired by skating, a team at the Chinese Academy of Sciences has created an anti-icing coating that uses a self-lubricating layer of water between the ice and the sample surface. The team will report its latest results at the APS March Meeting.
“Our approach is completely different from conventional anti-icing methods, which are usually energy-consuming, high-cost, and environmentally harmful,” said author Jianjun Wang, who will present the team’s work at the meeting. Using water as the lubricant is both eco-friendly and cost effective, he added.
The coating uses hygroscopic polymers, which attract and hold water. As the temperature drops, these hygroscopic polymers begin to swell as they collect the water in their vicinity. A lubricating layer of water therefore forms naturally as the icing occurs.
The team has found that the ice that forms on top of this water layer can be blown off by a strong breeze or fall off due to its own gravity. The anti-ice layer reduces ice adhesion on solid surfaces such as metals, ceramics, and polymers by more than one order of magnitude compared to that of untreated surfaces, they report. And unlike organic lubricants, which become depleted over time, the lubricating layer remains as long as ice stays on top of the surface.
Future plans include optimizing the recipe for the coating so that ice can be shed off more easily and commercializing the product.