Researchers have created a new “smart” self-healing coating that can help prolong the life of structures, automobiles, and infrastructure by preventing the formation of rust.
The new material, developed by nanomaterials researchers at the University of Queensland (UQ), activates as damage occurs, allowing it to respond before oxidation that leads to rust.
At the heart of the innovation are powdery particles that can be added to water-based paint, which can transform coatings used in everyday applications into self-repairing barriers against corrosion. During lab tests, the researchers discovered that the new substance impedes corrosion by more than 600 times when compared to conventional protective coatings.
“All rustproof coatings inevitably wear down over time; there is no stopping that,” said Dr. Asep Nugraha of UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN).
“What we have created is a barrier that is constantly sensing if something is wrong so it can patch any scrapes and cracks itself, greatly extending the duration of protection.”
The Deep History of Self-Healing Technology
While such innovations showcase a modern breakthrough in anti-corrosion coatings, self-healing technologies have surprisingly deep roots.
For many years, engineers marveled at the durability of ancient concrete used by Roman architects. Ultimately, analysis revealed that components used in the mixing process, which included volcanic ash that introduced pumice particles, led to the formation of new mineral deposits within the concrete, allowing it to self-heal over long periods, thereby enhancing its strength and durability over time.
Recently, MIT researchers have successfully reverse-engineered this remarkable ancient technology, providing novel applications in the modern world based on innovations by Roman engineers that began more than 2,000 years ago.
The Self-Healing Technology of Tomorrow
For Nugraha and the UQ team’s new technology, they utilized similar microscopic structures within the material they created, which act as tiny containers filled with molecules that combat the formation of rust.
The coating was developed by using benzotriazole, a common inhibitor of corrosion, introduced within an intricate nanostructure that can then be blended with water-based polyurethane coatings, producing a material that’s highly responsive to changes in acidity associated with corrosion.
“Each tiny particle is basically a nanocontainer that releases repair molecules only when the conditions demand it,” Nugraha said.
Tests revealed that the coating could restrict corrosion to around 37 nanometers annually, whereas many high-performance rust-protection products can only achieve a fraction of that performance, averaging around 0.025 millimeters per year.
The new experimental coating is 600 times more effective than similar existing anti-corrosion technologies.
Saving Money Through Durability
With costs associated with preventing corrosion amounting to as much as $90 billion annually, maintaining public infrastructure can quickly become very costly. Such next-generation anti-corrosion technologies could therefore greatly reduce such expenses, as well as the frequency of reapplication.
“For structures like bridges, applying a rustproof coating comes at great effort and cost, often to the public,” Nugraha said.
“But imagine, for example, if you only had to put a single coat of paint on the Story Bridge that protected it for more than 100 years.” Nugraha and the team concede that it may take additional work to achieve such century-long protection, but in its existing form, the technology does already significantly increase the length of time the coating offers protection in between maintenance cycles.
“It is not a coating that will last forever, but coatings that contain our technology will have a greatly expanded lifetime, meaning far less maintenance and a much longer time between applications,” Nugraha said.
Anti-Rust Tech in the Years Ahead
Right now, the researchers anticipate that the new smart coating will begin pilot-scale testing in the near future, and the technology could lead to the development of a commercial product as soon as within the next five years.
“Nanoarchitects work at an extremely small scale to build things that often defy what is physically possible,” Nugraha said.
“It is incredible to think that we could soon be telling people they might not have to worry about something rusting for several lifetimes.”
The team’s recent study, “Micelle‐Assisted Encapsulation Strategy in Metal‐Organic Framework Nanocontainers Enables Durable Corrosion Protection,” was published in the journal Small Science.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.