Novel Ice-Shedding Surfaces

Ice accretion has a negative impact on critical infrastructure, as well as a range of commercial and residential activities. Icephobic surfaces are defined by an ice adhesion strength t_ice < 100 kPa. However, the passive removal of ice requires much lower values of t_ice, such as on airplane wings or power lines (t_ice < 20 kPa). Such low t_ice values are scarcely reported, and robust coatings that maintain these low values have not been reported previously. In the first part of the talk, I will discuss how, irrespective of material chemistry, by tailoring the crosslink density of different elastomeric coatings, and by enabling interfacial slippage, it is possible to systematically design coatings with extremely low ice-adhesion (t_ice< 0.2 kPa). By utilizing these mechanisms, we fabricate extremely durable coatings that maintain t_ice < 10 kPa after severe mechanical abrasion, acid/base exposure, 100 icing/de-icing cycles, thermal cycling, accelerated corrosion, and exposure to Michigan wintery conditions over several months.



Next, we will discuss how the force required to remove ice from a surface is typically considered to scale with the iced area. This imparts a scalability limit to the use of icephobic coatings for structures with large surface areas, such as power lines or ship hulls. I will then describe a class of materials that exhibit a low interfacial toughness with ice, resulting in systems for which the forces required to remove large areas of ice (few cm² or greater) are both low and independent of the iced area. Coatings made of such materials allow ice to be shed readily from large areas (~1m²) merely by self-weight.