Graphene coat could rust-proof steel

A non-toxic, graphene-based composite for rust-proofing steel is in the works, and could replace the current coatings, which contain a probable carcinogen. In initial experiments, pieces of steel coated with the high-tech varnish remained rust-free for only a few days when immersed continuously in saltwater, an environment that accelerates corrosion. But by adjusting the concentration and dispersion of graphene within the composite, the amount of time steel survived in brine increased to about a month. Because brine is an extremely harsh environment, the coated steel’s survival time in the real-world would be many times longer. Bringing the coating to market would not only benefit public health, but also save jobs, say Sarbajit Banerjee, assistant professor of chemistry at University at Buffalo and Ph.D. student Robert Dennis. “Our product can be made to work with the existing hardware of many factories that specialize 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.” Graphene, the thinnest and strongest material known to humans, 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, Banerjee says. Tata Steel, an international company that has provided past funding for Banerjee’s projects, has been helping test larger sample sizes. UB’s Office of Science, Technology Transfer and Economic Outreach (STOR) has submitted a provisional patent application to protect the coating. As sponsors of the research and due to inventive contribution by Tata employees, Tata Steel also has certain rights to the technology. “The development of an environmentally friendly alternative to hexavalent chromium would truly revolutionize this sector,” says Anahita Williamson, director of the New York State Pollution Prevention Institute (NYSP2I), a research and technology transfer center funded by the New York State Department of Environmental Conservation. “The metals plating industry identified this as a high-priority research project and NYSP2I is excited to support UB researchers in their efforts to develop solutions.” The New York State Pollution Prevention Institute, headquartered at Rochester Institute of Technology (RIT), is a partnership among RIT, Clarkson University, Rensselaer Polytechnic Institute, UB and the state’s network of Regional Technology Development Centers.