Using Graphene, Scientists Develop a Less Toxic Way to Rust-Proof Steel

Bringing the coating to the market could not only benefit public health, but also save jobs

University at Buffalo researchers are making significant progress on rust-proofing steel using a graphene-based composite that could serve as a nontoxic alternative to coatings that contain hexavalent chromium, a probable carcinogen.

In the scientists’ first 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.

By adjusting the concentration and dispersion of graphene within the composite, the researchers increased to about a month the amount of time the treated steel can survive in brine. (Because brine is an extremely harsh environment, the coated steel’s survival time in the real-world would be many times longer.)

The UB chemists leading the project are Sarbajit Banerjee, PhD, an assistant professor, and Robert Dennis, a PhD student. Their next step is to use a $50,000 grant from the New York State Pollution Prevention Institute to enhance the graphene composite’s lasting power, as well as the quality of its finish.

Tata Steel, an international company that has provided past funding for Banerjee’s projects, has been helping the scientists test larger sample sizes, Banerjee said.

Bringing the coating to the market could not only benefit public health, but also save jobs, said Dennis and Banerjee.

“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 said. “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 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, Banerjee said.