Hadi Ghasemi illustrates how a drop of water rolls off his novel icephobic surface. Photo: Cullen College of Engineering.Icy conditions can be deadly, whether you're flying into bad weather or standing too close to power transmission lines during a storm. Researchers at the University of Houston (UH) have now found a way to reduce these risks, by developing a material that can be applied to any surface to repel ice. The material, termed a magnetic slippery surface (MAGSS), is described in a paper in Nature Communications.
Hadi Ghasemi, assistant professor of mechanical engineering at UH and principal investigator for the research, said the material outperforms all others currently in use. Four of Ghasemi’s students are listed as co-authors on the paper: Peyman Irajizad, Nazanin Farokhnia, Seyed Mohammad Sajadi and Munib Hasnain.
"Anti-icing surfaces have a critical footprint on daily lives of humans ranging from transportation systems and infrastructure to energy systems, but creation of these surfaces for low temperatures remains elusive," the researchers wrote in the paper. "Non-wetting surfaces and liquid-infused surfaces have inspired routes for the development of icephobic surfaces. However, high freezing temperature, high ice adhesion strength, and high cost have restricted their practical applications."
The researchers’ novel process for making a surface icephobic involves coating one side of the surface with a magnetic material, while depositing a thin layer of magnetic fluid – a mixture of fluid and iron oxide nanoparticles –on the other side, facing the external world. When a droplet of water hits the surface, the magnetic fluid acts as a barrier, stopping the droplet from reaching the solid surface.
"There's no adhesion of the ice to the solid surface, so it basically slides off the surface," Ghasemi explained.
Potential applications for the icephobic MAGSS range from the aircraft industry – planes can encounter freezing rain or super-cooled water droplets while flying, leading to a build-up of ice and, potentially, a crash – to the power industry, where icing can cause power poles, towers and transmission lines to collapse.
Ultimately, Ghasemi hopes to develop the coating as a spray that can be applied to any surface. He has a patent pending on the discovery.
"These surfaces (MAGSS) provide a defect-free surface for ice nucleation and thereby lower the ice formation to close to homogenous nucleation limit," the researchers wrote. "These surfaces promise a new paradigm for development of icephobic surfaces in aviation technologies, ocean-going vessels, power transmission lines and wind turbines in extreme environments."
Among the advantages of MAGSS, Ghasemi said, is that it has a far lower freezing threshold than the best icephobic technology currently available – about -29°F, compared to -13°F for current technology. "These new surfaces provide the path to tackle the challenge of icing in systems, thereby improving the quality of human life," he said.
This story is adapted from material from the University of Houston, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.