Pitt-led researchers create nanoparticle coating to prevent freezing rain buildup

Inspired by water-resistant lotus leaves, the Pitt-developed solution repels freezing rain and provides the first evidence of anti-icing ability in superhydrophobic coatings, team reports in Langmuir

PITTSBURGH—Preventing the havoc wrought when freezing rain collects on roads, power lines, and aircrafts could be only a few nanometers away. A University of Pittsburgh-led team demonstrates in the Nov. 3 edition of Langmuir a nanoparticle-based coating developed in the lab of Di Gao, a chemical and petroleum engineering professor in Pitt's Swanson School of Engineering, that thwarts the buildup of ice on solid surfaces and can be easily applied.

The paper, by lead author and Pitt doctoral student Liangliang Cao, presents the first evidence of anti-icing properties for a burgeoning class of water repellants—including the Pitt coating—known as superhydrophobic coatings. These thin films mimic the rutted surface of lotus leaves by creating microscopic ridges that reduce the surface area to which water can adhere. But the authors note that because ice behaves differently than water, the ability to repulse water cannot be readily applied to ice inhibition. Cao's coauthors include Gao, Jianzhong Wu, a chemical engineering professor at the University of California at Riverside, and Andrew Jones and Vinod Sikka of Ross Technology Corporation of Leola, Pa.

The team found that superhydrophobic coatings must be specifically formulated to ward off ice buildup. Gao 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, at the largest. They applied each variant to aluminum plates then exposed the plates to supercooled water (-20 degrees Celsius) to simulate freezing rain.