If progress on a product that researchers at the University at Buffalo (New York) are working on is any guide, steel which does not rust and does not need toxic chemicals to prevent rust may soon become a reality.
Recent experiments suggest the researchers are making progress on rust-proofing steel using a graphene-based composite that could serve as a non-toxic alternative to coatings that contain hexavalent chromium, a probable carcinogen.
In a recent experiment, when immersed continuously in saltwater – an environment that accelerates corrosion – pieces of steel coated with the high-tech varnish remained rust-free for only a few days.
That increased to about a month, however, when the researchers adjusted the concentration and dispersion of graphene within the composite.
Better yet, because brine is an extremely harsh environment, rust would take many times longer to occur in the real world, the university says.
Graphene, the thinnest and strongest material known to man, consists of a single layer of carbon atoms linked in a honeycomb-like arrangement.
The material’s hydrophobic and conductive properties may help prevent corrosion, repelling water and stunting electro-chemical reactions that transform iron into iron oxide, or rust, says assistant professor Sarbajit Banerjee who, together with PhD student Robert Dennis, is leading the project.
Once brought to market, Banerjee says, the new coating could save jobs and improve public health.
“Our product can be made to work with the existing hardware of many factories that specialise in chrome electroplating, including job shops in Western New York that grew around Bethlehem Steel,” Banerjee says. “This could give factories a chance to reinvent themselves in a healthy way in a regulatory environment that is growing increasingly harsh when it comes to chromium pollution.”
Anahita Williamson, director of the New York State Pollution Prevention Institute (NYSP2I), a research and technology transfer centre funded by the New York State Department of Environmental Conservation, agrees.
“The development of an environmentally friendly alternative to hexavalent chromium would truly revolutionise this sector,” she says.
The university says the next step will be to use a $50,000 grant from the NYSP2I to enhance the graphene composite’s lasting power, as well as the quality of its finish.
Already, Tata Steel, an international company that has provided past funding for Banerjee’s projects, has been helping the scientists test larger sample sizes.
UB’s Office of Science, Technology Transfer and Economic Outreach has submitted a provisional patent application to protect the coating Banerjee and Dennis are refining. As sponsors of the research, Tata Steel will also have certain rights to the technology.