There’s a surprisingly large need out there for surfaces that repel things. For instance, it could allow for building panels that repel water—or oily stains or residues—so efficiently that rain would wash them, making them self-cleaning. Or even biomedical products, including microfluidic technologies, that don’t get clogged by watery or fatty materials sticking to them. “I am looking for an eyeglass coating, but this could have important applications around medicine, too,” says Doris Vollmer, a materials scientist in the Max Planck group. “For many applications, people would like oil repellence. It’s not sufficient that something is water-repellent.”
While the researchers used candle soot, soot particles of similar sizes are available commercially, leading the way to potential manufacturability at high scale and low cost, she adds. The group is exploring commercial partnerships to advance the technology.
Ambarish Kulkarni, a mechanical engineer in the Advanced Nanotechnology program at GE Global Research—which also seeks superamphiphobic material surfaces—says the paper describes a “novel method” of making them. The GE researchers have found that such surfaces provide antifouling benefits inside gas turbines, potentially making them run more cleanly and efficiently.
Because the Max Planck method allows the materials to work at high temperatures, it “may open application areas previously unachievable,” he adds.
GE has several projects in this area, including an effort to instill superhydrophobic roughness on the surface of common thermoplastics used for things like product and food packaging.
One problem with the Max Planck coating is that, in contrast to roughened surfaces used for various water-repellant surfaces, it can get scratched or wear off. So the materials technology will need further refinements to make oil-resistant eyeglasses that are also truly scratch-resistant, Vollmer concedes. She is also working on ways to make the coating in chemical solutions, rather than the initially used vapor deposition method, which require high-temperature ovens.