A team of scientists at Northwestern University are developing a coating for metal, inspired by fluids, that is able to self-heal in moments when it is scratched, cracked, or scraped. The material is so effective that it can repeatedly self-heal even after being scratched over 200 times in a row. Their research was recently published in the journal Research. The scientists hope that this material could help prevent corrosion on everything from airplanes to bridges.
“When a boat cuts through water, the water goes right back together. The ‘cut’ quickly heals because water flows readily. We were inspired to realize that fluids, such as oils, are the ultimate self-healing system,” says Jiaxing Huang lead researcher of the study at Northwestern University. “The particles essentially immobilize the oil film, so it stays in place.”
From the Northwestern University article "The team met the challenge by creating a network of lightweight particles — in this case graphene capsules — to thicken the oil. The network fixes the oil coating, keeping it from dripping. But when the network is damaged by a crack or scratch, it releases the oil to flow readily and reconnect. Huang said the material can be made with any hollow, lightweight particle — not just graphene.
The coating not only sticks, but it sticks well — even underwater and in harsh chemical environments, such as acid baths. Huang imagines that it could be painted onto bridges and boats that are naturally submerged underwater as well as metal structures near leaked or spilled highly corrosive fluids. The coating can also withstand strong turbulence and stick to sharp corners without budging. When brushed onto a surface from underwater, the coating goes on evenly without trapping tiny bubbles of air or moisture that often lead to pin holes and corrosion."
Read more about the rapidly healing metal coating that prevents corrosion at Northwestern University.