Icing imposes a significant burden on those living in cold climates, with negative impacts on infrastructure, transportation, and energy systems. Over the past few decades, a wide range of materials with ice-shedding characteristics have been developed, but many tend to have very low durability, limiting their effectiveness. Although many of these materials have demonstrated low ice adhesion in a laboratory setting, none have achieved widespread practical adoption. Thus, the primary challenge in developing ice-shedding materials is finding materials with both low ice adhesion and good durability.
Now, engineers at the University of Houston have developed a sprayable ice-shedding material that is 100 times stronger than any others. The new durable coating material offers both low ice adhesion and good durability.
The principle of the new “fracture-controlled material” lies in the fact that for detachment of any external solid object from a surface (like ice from an airplane wing), force must be applied, and that force will inevitably lead to the formation of some cracks at the interface. These cracks, or fractures, grow until a full detachment of the object from the surface.
Through coordinated mechanical and chemical heterogeneity in the material structure, engineers affect the interfacial crack nucleation and growth on these surfaces. Through this controlled process, fracture-controlled surfaces exhibit both low ice adhesion and very high mechanical durability.
The results indicated that the new sprayable ice-shedding material is 100 times stronger than any others. The coating material has been tested by Boeing under erosive rain conditions at 385 miles per hour and has outperformed current state-of-the-art aerospace coating technologies.
“We developed a new concept in which, through material design, you can significantly accelerate the crack formation and growth and easily remove external objects from the surface. This concept is implemented to develop materials that are highly durable, and ice does not attach to these materials,” reports Ghasemi in the cover article of Materials Horizons. “Fracture-controlled surfaces provide a rich material platform to guide future innovation of materials with minimal adhesion while having very high durability,” said Ghasemi.
According to the researchers, this new fundamental concept of fracture-controlled materials paves the way for innovations in materials for aerospace, wind energy, and other industrial and commercial applications where icing is an issue. Ice buildup on wind turbines could lead to an 80% drop in power generation, which could be avoided through these new coating materials.
- Sina Nazifi, Zixu Huang, Alireza Hakimian, Hadi Ghasemi. Fracture-controlled surfaces as extremely durable ice-shedding materials. Materials Horizons, 2022; DOI: 10.1039/D2MH00619G