Last week, the city of Luxembourg played host to The Economist’s “The Future of Materials Summit”. The agenda was heavily influenced by the Russian-based single-wall carbon nanotube (SWNTs) producer, OCSiAl, which not only sponsored the event but also plans to open a SWNT production facility in Luxembourg.
With the Luxembourg prime minister, Xavier Bettel, providing a keynote in which he expressed his hope that Luxembourg could bring back its manufacturing glory days when it was one of Europe’s largest steel producers, the hope seemed to be squarely placed on the potential of SWNTs to be the engine for Luxembourg’s economic transformation back to manufacturing.
In what may have been the most interesting set of ironies of the conference, one of the world’s largest steel producers today—Tata Steel—provided testimony that the future of steel manufacturing is not turning towards the expensive and finicky SWNTs, but instead is developing a cheaply produced form of graphene that promises to drastically improve corrosion resistance in steel.
Sanjay Chandra, Chief of Research and Development and Scientific Services at Tata Steel, provided one of the only examples at the conference on how novel materials move from discovery to high volume production. And in this case, the discovery process was quite unexpected.
“We were looking at coatings that would improve the corrosion resistance of steel,” said Chandra in an interview immediately after his presentation. “There is already zinc, of course, but there are a lot of environmental issues with the zinc as well as the costs associated with it. So we came across this bio product from a tree. It is the secretion that an insect makes as it sits on the seeds of the tree. You could call it a bio extract, and we were able to convert this material into graphene.”
The graphene takes the form of graphene oxide in which the carbon-to-oxygen ratio is about 30% to 40%, and, according to Chandra, it provides very good corrosion resistance.
“Its conductivity is good enough for some of the sensors that are used in the pharmaceutical industry and the main feature of our product is that can we can produce it at a very low cost because it can be produced in very large volumes and very rapidly,” said Chandra.
Currently, the process that Chandra and his colleagues at Tata Steel are employing with the graphene oxide is a manual process of dipping the steel in a liquid created by this powder. While this is good enough for testing, Chandra concedes that in order to replace zinc in steel production they will need to develop a more refined process.
“We need a process that can fit into a steel plant that is producing these galvanized sheets of steel at very high speeds and all in one sequence,” he added. “So for us to be able to do that that's a bit of a challenge.”
Part of the challenge is that it is very difficult to get someone to retrofit a steel assembly line because of production disruptions. However, with the graphene material offering at least a doubling of corrosion resistance over zinc and offering biocompatibility there is certainly reason to look into overcoming these production obstacles.
Most of the research and development that has been done so far with the material and processes has been performed in house at Tata Steel. Chandra explained that this was not because of any reticence to work with outside research groups—which Tata Steel does quite regularly—but instead they have not been able to identify the appropriate group that could help them scale up the production for steel applications. Another problem is just the culture of the steel industry, which has proven to be not very good at engineering and design, which is where the current problems resides.
To address these issues Tata Steel has taken the forward thinking measure of funding a new research group at the Indian Institute of Technology in Madras to look at among other things this material and how to potentially scale up production. Tata steel has also enlisted the research support of The Centre for Nano Science and Engineering (CeNSE) in Bangalore, India to investigate the potential sensor applications of the graphene material.
For Chandra the project has been ongoing for the last two-and-a-half years, and he says the development that has been made thus far has been very fast. “We’ve gone from a research curiosity and then to a research project in R&D to where we are now with a small production unit on the R&D level,” he added.
In addition, Chandra believes that the work at CeNSE could start producing tangible dividends from their research in as soon as a year from now. The material could enable glass to turn from clear to opaque with just the passing of current through it with the graphene providing the conductivity in the glass.
In the meantime, Chandra is looking for other collaborators, especially any organizations that can offer expertise and insight on how to scale up a steel production process that employs a graphene oxide for corrosion resistance.