The patent-pending system reconnects to repair within a few seconds, and is able to repeat the repairing process even when the same spot is damaged over and over again.
Self-Repairing Coating
“Localized corrosion is extremely dangerous,” said research lead Jiaxing Huang, a professor of materials science and engineering at the university’s McCormick School of Engineering. “It is hard to prevent, hard to predict and hard to detect, but it can lead to catastrophic failure.”
According to the university, though some self-repairing coatings already exist, these are largely geared toward fixing nanometer- to micron-sized areas of damage. To address millimeter-sized scratches, the research team examined fluid.
“When a boat cuts through water, the water goes right back together,” Huang said. “The ‘cut’ quickly heals because water flows readily. We were inspired to realize that fluids, such as oils, are the ultimate self-healing system.”
Since common oil flows too readily, Huang and his team needed to create a system that was fluid enough to flow automatically, while also not dripping off the surface of the substrate. To address those needs, the team created a network of lightweight particles composed of graphene capsules to thicken the oil; this prevents the oil coating from dripping, but when the coating is damaged, the coating can flow and reconnect.
“The particles essentially immobilize the oil film,” Huang said. “So it stays in place.”
Huang also noted that the material can be made with any hollow, lightweight particle; graphene is just one option.
Results also indicate that the coating is suitable for use underwater and in harsh chemical environments, such as acid baths, and can withstand strong turbulence.
The study was published earlier this week in Research, the first Science Partner Journal recently launched by the American Association for the Advancement of Science working in collaboration with the China Association for Science and Technology. The study was supported by the Office of Naval Research.
