Like most things, ice can be a blessing or a burden depending on the circumstances. It’s perfect crushed in a drink on a hot summer’s day, but can wreak havoc when it collects on roads, power lines and aircraft in freezing temperatures. A University of Pittsburgh-led team has found a way to reduce these dangers by developing a nanoparticle-based coating that can be easily applied to impede the buildup of ice on solid surfaces.
The superhydrophobic coating developed by the researchers mimics the rutted surface of lotus leaves by creating microscopic ridges that reduce the surface area to which water can adhere. Although the surface of the lotus leaf has already served as the inspiration for self-cleaning plastics, more efficient solar cell surfaces, and a special coating for spaceflight equipment, because ice behaves differently than water, relying on the same method used to repulse water used in these examples couldn’t be readily applied to ice.
To ward off ice buildup the team found that superhydrophobic coatings must be specifically formulated. Di Gao, a chemical and petroleum engineering professor in Pittsburgh University’s Swanson School of Engineering, and his team created different batches made of a silicone resin-solution combined with nanoparticles of silica ranging in size from 20 nanometers to 20 micrometers. They applied each variant to aluminum plates then exposed the plates to supercooled water (-20 degrees Celsius) to simulate freezing rain.