Navy Backs 'Omniphobic' Marine Coatings
Anish Tuteja, an associate professor of materials science and engineering at the University of Michigan, recently spearheaded research into an omniphobic coating—an “everything repellent” that could be used to help ships glide through the water with much less friction than other vessels.
Customary research in this field targets combining the most repellent filler material with an equally durable polymer matrix. Instead, the research team looked for the best combination by scanning a number of databases for chemicals, mathematically predicting to see how two would work together.
During research, the team discovered that a property called “partial miscibility"—or the ability of two substances to mix together in exactly the correct way—was more important than durability or repellency.
According to a press release from the University of Michigan, making an optically clear, versatile coating, which was also smooth enough to repel alcohols and oils, posed a unique challenge: The researchers needed to find a repellent ingredient and a binder with exactly the right amount of miscibility, while also being able to stick to a variety of substrates.
The team eventually found that a mixture of fluorinated polyurethane and a specialized fluid-repellent molecule called F-POSS did what they needed it to do—the concoction could be sprayed, brushed, dipped or spin-coated onto a number of surfaces.
“The repellent and binder mix together well enough to make a clear coating, but there’s a very small amount of phase separation between them,” said Mathew Boban, a materials science and engineering graduate researcher and fellow paper author. “That separation allows the F-POSS to sort of float to the surface and create a nice repellent layer.”
Tuteja noted that the coating will likely be inexpensive by the time it hits the mass market; F-POSS is rare and expensive now, but it is being scaled up to mass production, which will help reduce cost.
Research for the paper, titled “Smooth, All-Solid, Low-Hysteresis, Omniphobic Surfaces," was funded by the Air Force Office of Scientific Research, Office of Naval Research and National Science Foundation. The University of Michigan and the U.S. Air Force have jointly filed patent applications related to the technology.
According to Engadget, the university hopes to have the coating ready for "small-scale" military and civilian purposes within two years.