Gel-Based Coating Fights Off Ice
Researchers at Colorado State University believe they have made a breakthrough in the realm of anti-icing coatings with the invention of a new ice-repellent coating they claim outperforms today’s best de-icing products.
A team led by Arun Kota, assistant professor of mechanical engineering and biomedical engineering, created a coating that is said to be one that is environmentally friendly, inexpensive and long lasting, the university announced Thursday (Nov. 17).
The new coating could play a role in keeping everything from cars and ships to planes and power lines ice-free, it added.
Soft, Gel-based Coating
The team’s ice-repellent coating is described as a gel-based, soft coating made out of PDMS (polydimethylsiloxane), a silicone polymer gel with already widespread industrial use.
In describing the difference between de-icing and anti-icing coatings, Kota explains that anti-icers delay the formation of ice, while de-icers facilitate easy removal of ice after it has already formed and stuck to a surface.
The liquid de-icers (ethylene glycol or propylene glycol) typically sprayed on frozen planes before takeoff work pretty well, the team says, adding that the spraying of salts or glycols is the most common passive de-icing technique used today. The aviation industry alone uses more than 20 million gallons of de-icing chemicals each year, according to the U.S. Environmental Protection Agency.
However, these liquid products have to be applied over and over again, and leach into groundwater, raising environmental concerns
Kota’s team’s innovation, he says, could provide an environmentally friendly, high-performance alternative to the use of toxic liquid de-icers, as it would be applied as a more permanent protective coating.
“We think there is significant commercial potential here,” Kota notes.
Ice Adhesion Testing
To test its effectiveness, they relied on experiments that involved careful analysis of ice adhesion mechanics.
The performance measure of de-icing coatings is called ice adhesion strength—that is, the shear stress necessary to remove ice from a surface, which is measured in kilopascals (kPa). The pascal is a unit of pressure used to quantify internal pressure, stress and tensile strength.
Kota’s group demonstrated an ice adhesion strength of about 5 kPa for its coating. By contrast, soft coatings available on the market have an ice adhesion strength of about 40 kPa—lower is better, Kota clarified.
Other types of de-icing coatings made of rigid materials like Teflon typically perform at around 100 kPa, he added.
Their research was published this month in Journal of Materials Chemistry A.