Scientists at Rice University have created a material that will protect steel from corrosion. In fact, it will also be flexible and heal itself when damaged.
This material will be used as a coating and is made from a lightweight sulfur-selenium alloy. It will be able to block moisture and chlorine-like zinc- and chromium-based coatings, protect steel under seawater-like conditions like polymer-based coatings, keep it from microbe-induced corrosion.
The experiments carried out before the results comprised putting small slabs of common mild steel coated with sulfur-selenium alloy in seawater for a month, along with an uncoated slab of steel as a control. The coated steel did not oxidize.
It was then tested against sulfate-reducing bacteria that speed up the corrosion. Coated and uncoated samples were exposed to plankton and biofilms. The alloy protected the steel. The scientists stated that the coating offered an “inhibition efficiency” of 99.99 percent.
Lastly, the film was cut in half and the two pieces were placed next to each other on a hot plate, they reformed into a single, foldable film within two minutes when heated to 70 °C (158 °F). Pinholes could also be repaired by heating the material to 130 °C (266 °F) for 15 minutes.
“If you give the alloy a poke, it recovers,” says study author Muhammad Rahman. “If it needs to recover quickly, we assist it using heat. But over time, most thick samples will recover on their own.”
“The first target structures, but we’re aware the electronics industry faces some of the same problems with corrosion,” says study author Pulickel Ajayan. “There are opportunities.”
The research was published in the journal Advanced Materials.