Vol 9 Issue 3

When I was studying Chemistry, I remember being fascinated by a massive wood and glass cabinet at the college entrance. It was a periodic table containing actual samples of the elements. The lasting impression was how many of the elements were metals. Non-metals are in the minority. There is method in my recollection. A few weeks ago, a new form of carbon was announced by a team in the USA. They call it U-carbon and it is metallic. It conducts electricity, is magnetic and the sample they have made looks just like a highly polished metal mirror. Carbon is not a metal. Or is it? U-carbon is a layered combination of 2D and 3D material. This one will keep scientists arguing about definitions for some time to come. In the meantime, the applications for something that is mirror-like, has a very high melting point, is electrically and thermally conductive as well as magnetic and extremely hard, will be myriad. U-carbon is something to watch. Another research project hit the headlines this month. The University of Arkansas announced they had made a device using graphene that extracts limitless electrical energy from Brownian motion. I spent several days with two of the smartest people I know to figure out what was actually going on here because this work appears to invalidate earlier work by Richard Feynman. We think we’ve got to the bottom of this and while their device works at the small scale, we think they will encounter problems scaling up and discover that Richard was right all along. Time will tell. Yet more fascinating work has been done by the Pacific Northwest National Laboratory. They have made a new material; a graphene-copper metal composite. This is a new shear forming technique for making metal components and wires from powders. This shows 5% improved electrical conductivity compared with copper. General Motors is already working with this to lightweight their electric vehicles. We can see huge opportunities in space and clean energy where lightweighting electrically conductive copper will be a significant leap forward. Chinese electronics hardware company MSI has embraced graphene composites. Their latest graphics card has a casing made from a graphene enhanced polymer that is four times stronger and conducts heat sixteen times better than the normal plastic they used for the casing. Another eye-catching development was made by researchers at the University of Surrey. They have found that adding small amounts of graphene to an acrylate-based polymer makes it look like a green opalescent material. More importantly its colour changes red when squeezed and blue when stretched. This is reversible. It also responds to temperature too, losing its colour irreversibly above a set temperature. This means they have created a sensor that does not need batteries. As usual there is so much more in this issue, the pace of this field is astonishing. Adrian Nixon, 1st November 2020

Regular readers will be aware of my view that the field of graphene is moving faster than anyone realises. More evidence supporting this emerged this month. A team at Penn State university in the USA has been working on experiments with passing sound waves through sheets of graphene with precise holes drilled in hexagonal patterns. They made the acoustic analogue of twisted bilayer graphene and found the acoustic equivalent of the magic angle. So, as well as twistronics for electrons we now have phononics for sound waves in twisted bilayer graphene, and probably other 2D materials. A new field of scientific study made possible by graphene the progress really is astonishing. The US Government is starting to wake up to the power of graphene. James Tour’s flash graphene is attracting the attention. The team now can take the waste char from plastic recycling and turn it in to graphene that improves the strength of cement by 30%. Rice University says the Air Force Office of Scientific Research and the Department of Energy supported the research. Trade magazines in the construction sector are also picking up on this. Another development by James Tour; Laser induced graphene is being used to make biosensors that detect and diagnose SARS-CoV-2 in blood and saliva samples. The test links to a smartphone and produces results in ten minutes. More work is being done with graphene supercapacitors. It looks like increasing the surface area of graphene nanoplates by increasing the separation between the nanoplates increases the energy density. Cross linking the nanoplates with a big molecule that is also electrically conductive improves the supercapacitor performance still further. Computer graphics card manufacturer, Gigabyte, has launched a new high end gaming card. Graphene is being used to improve the cooling performance, interestingly not using the thermal properties, but using graphene as a lubricant. Investors seem to be taking a more active interest in graphene companies. Ionic, the Australian supercapacitor manufacturer has received $2million to develop its manufacturing operation. In the UK Versarien has raised another £3.5million and Applied Graphene Materials has raised £6million in cash by selling more shares. This gives both companies some financial breathing room but also raises the pressure to deliver revenue growth. And there is lots more of interest in this packed issue. Adrian Nixon, 1st February 2021