Zentek Develops Icephobic Coating
Zentek Ltd., a Canadian development and commercialization company, recently announced the development of a new carbon-based, nanotechnology-enhanced icephobic coating.
Tests for adhesion strength required to dislodge ice from surfaces were conducted with a third-party lab, with the coating reportedly demonstrating an adhesion strength consistently around 20 kilopascals. ZEN reports that the typical ice adhesion strength of a bare aluminum alloy is about 500 kilopascals, while a classified icephobic surface must be less than 100 kilopascals, with the coating having a 96% improvement over aluminum and 80% improvement over the 100 kPa threshold.
“We continue to actively develop new nanotechnology-enabled applications in high-impact areas, which, in this case, has the potential to significantly increase safety for vehicles such as drones, aircraft, ocean vessels, wind turbines and other applications where, in cold weather climates, there is the potential for ice to accrete on surfaces, causing hazardous breakdowns in function,” said Greg Fenton, ZEN CEO.
“Our mission continues to be to develop innovative nanotechnologies that improve people’s lives – and while our focus is primarily on nanotechnology-enabled healthcare solutions – we are also making breakthroughs that substantially contribute in other industries that may result in vital steps forward to ensure public safety and enhance sustainability.”
ZEN plans to include this coating, which includes graphene, in flight testing under real world ice-forming weather conditions this winter, as well as testing if the coating is an effective passive method to de-ice drone propellers to fly safely in all-weather operations.
According to the release, the company filed a provisional patent for the technology in August with the United States Patent and Trademark Office and has begun to explore partnership opportunities.
Other Anti-Ice Coatings Research
Earlier this year, the U.S. Army Corps of Engineers applied for a patent on an ice adhesion testing device.
According to reports, the device creates high-quality ice samples on a surface or coating of interest so that computational models can better describe ice adhesions and enable the creation of anti-icing systems.
The device is meant to help protect critical systems, such as aircraft and marine vessels.
“This apparatus is … for measuring the force required to break a single interface formed by two solid materials, where one material is the adhesive of interest. For example, the adhesion of ice to various coated or uncoated materials can be tested in this way,” the patent application states.
“Many different specimen sizes can be accommodated, and a wide range of coating materials can be applied to the specimen surface so that the adhesive properties of coatings can be studied.”
The patent developers go on to explain later in the publication that the motivation for the new patent was partially due to a lack of industry standards for testing ice adhesion.
In February 2020, materials scientist Ximin He, along with a team of researchers from the UCLA Smaueli School of Engineering and colleagues reportedly developed an ice-prevention coating.
UCLA authors of the study included Zhiyuan He, Mutian Hua, Shuwang Wu and Dong Wu, in addition to colleagues Chenyang Wu and Jianjun Wang of the Chinese Academy of Sciences in Beijing, and Xinyuan Zhu of Shanghai Jiao Tong University.
Inspired by how Antarctic species of fish create proteins to prevent their blood from freezing, scientists from UCLA looked at how the formation of ice could be prevented by focusing on three main properties of what causes ice to form and how those same molecular structures could be recreated.
When creating the coating, scientists decided on the use of polydimethylsiloxane—a nontoxic, silicone-based polymer found in contact lenses, cosmetics, lubricants and other applications.
By spraying the polydimethylsiloxane-based gel onto a variety of surfaces, researchers found that the thin transparent coating successfully prevented freezing by lowering the freezing temperature of water on the surface, delaying ice crystal growth and creating a difficult surface for ice to adhere to.
Experiments using the coating were mostly conducted inside the university’s laboratory; however, one test was performed outdoors in below-freezing temperatures.
According to UCLA, the coating set a record for lowest temperature reached while preventing ice formation. It wasn’t until tests pushed the coating to -31 degrees Celsius (or -23.8 degrees Fahrenheit) that ice formed and remained on a surface’s profile. (Traditionally, water usually freezes at zero degrees Celsius).
The hydrogel also set a record for length of time delaying ice formation—taking more than 65 minutes to form ice at -25 degrees Celsius.
And in July of the same year, Cambridge, Massachusetts-based industrial technology company Adaptive Surface Technologies, Inc. announced that it was awarded a $499,000 Small Business Innovation Research Phase II contract from the United States Air Force to develop an icephobic coating that improves pre-flight and in-flight anti-icing properties on military aircraft and avionics.
The development of the coating for the USAF will reportedly be based on AST’s existing antifouling marine coating, which was launched last year.
That coating aims to reduce the adhesion and persistence of “unwanted biological fouling on any given surface.” The company says that modifications to the makeup of the coating will be made to focus on ice-repellency and durability.