The spray-on coatings, developed at the University of Michigan, cause ice to fall away from structures—regardless of their size—with just the force of a light breeze, or often the weight of the ice itself. A paper on the research is published in Science. The researchers overcame a major limitation of previous ice-repellent coatings—while they worked well on small areas, researchers found in field testing that they didn’t shed ice on very large surfaces as effectively as they had hoped. That’s an issue, since ice tends to cause the biggest problems on the biggest surfaces—sapping efficiency, jeopardizing safety and necessitating costly removal.
They cleared this hurdle with a “beautiful demonstration of mechanics.” Anish Tuteja, an associate professor of materials science and engineering, described how he and his colleagues turned to a property that isn’t well-known in icing research. The new coatings solve the problem by introducing a second strategy to the known lowering of adhesion strength: low interfacial toughness, abbreviated LIT. Surfaces with low interfacial toughness encourage cracks to form between ice and the surface. And unlike breaking an ice sheet’s surface adhesion, which requires tearing the entire sheet free, a crack only breaks the surface free along its leading edge. Once that crack starts, it can quickly spread across the entire iced surface, regardless of its size.
www.news.umich.edu or publication “Low Interfacial Toughness Materials for Effective large-Scale De-Icing.”
Source: University of Michigan