Graphene is an incredible material – extremely good heat and electricity conductor and the strongest material on earth. Needless to say, it is very valuable in commercial setting, but it is also very hard to produce. One of the most famous methods to exfoliate graphene is the adhesive tape method developed by Nobel Prize winner Andre Geim, but how does it work?
This method is rather simple. It works by pulling graphene layers apart, picking up one atom thick flakes that form this valuable material. Interestingly enough, no one really knows exactly how it works. Scientists from UCL conducted a research to see why a sticky tape is so effective in peeling off layers of graphene. It turns out, this method is 40 % more energy-efficient than another common method called shearing. The reason is that adhesive tape allows lifting off a layer of graphene, instead of pushing it to the side.
Another interesting thing about this method is that an actual sticky tape is used – polymethyl methacrylate adhesive on traditional sticky tape works perfectly for picking up the edge of the graphene sheet. Grapehen is a very strong material that occurs naturally. Its crystalline structure means that a sheet of graphene has a honeycomb pattern of atoms. It is very strong, yet light and transparent. However, bonds between the different layers of graphene are weak and they can slide on top of each other great distances because of their superlubricity (yet another amazing characteristic).
Scientists now used a special microscope with atomic resolution to see how graphene flakes move around on a graphite surface. Researchers noticed that when layers are neatly lined up, they don’t slide around so much. This is very important to know in order to make graphene manufacturing at least a little bit easier. Peter Coveney, one of the authors of the study, noted that despite how hi-tech graphene may be, eve “a dozen years after its discovery, companies have to apply sticky tape methods to pull it apart, as the Laureates did to uncover it; hardly a hi-tech and industrially simple process to implement. We’re now in a position to assist experimentalists to figure out how to prise it apart, or make it to order”.
Graphene will see a number of applications across the industry. It will be interesting to see what scientists will come up with, but for any kind of breakthrough better manufacturing methods need to be developed.