Researchers at the University of Michigan in Ann Arbor have developed a spray-on coating that has proven much more durable than traditional commercial waterproofing methods. The technology could enable waterproofing of vehicles, clothing, rooftops, and other surfaces where current products are too fragile.
Additionally, the coating could lower the resistance of ship hulls, which would reduce fuel consumption and costs for vessels in the transportation and cargo industry.
The coating is made of a mix of material called fluorinated polyurethane elastomer and a specialized water-repellant molecule known as F-POSS, and can be sprayed onto virtually any surface. Once dried, the coating has a rubbery texture that researchers believe makes it more resilient than current products.
“Thousands of superhydrophobic surfaces have been looked at over the past 20 or 30 years, but nobody has been able to figure out how to systematically design one that’s durable,” says Anish Tuteja, U-M associate professor of materials science and engineering. “I think that’s what we’ve really accomplished here, and it’s going to open the door for other researchers to create cheaper, perhaps even better superhydrophobic coatings.”
Tuteja adds that if damaged, the coating can heal itself hundreds of times, and continues to function even after being abraded, scratched, burned, plasma-cleaned, flattened, sonicated, and chemically attacked.” The product can also heal itself chemically, if F-POSS molecules are scraped from the surface, new ones will naturally migrate there to replace them. Able to regenerate hundreds of times, the coating is only limited by its thickness.
The product is currently being commercialized by HygraTek, a company founded by Tuteja with assistance from the U-M Tech Transfer. Tuteja estimates that the coatings will be available for use before the end of 2017 for applications including water-repellent fabrics and spray-on coatings that can be purchased directly by consumers.