Testing DIY GrapheneRoger Pink | June 01, 2017
Since the start of the 21st century, one of the most researched materials in the scientific literature is graphene. Graphene is a single atomic layer of crystalline graphite. It is a planar honeycomb of carbon atoms with fascinating physical, thermal and electrical properties. Although graphene was observed attached to metal surfaces as early as 1962, it was thought it could not exist on its own due to thermodynamic instability. In other words, it was thought it would instantly melt if isolated. This was shown to be false when it was isolated and characterized in 2004 by Andre Geim and Konstantin Novoselov.
Giem and Novoselov found that graphene was in fact stable up to high temperatures. Other researchers soon discovered that graphene is both highly electrically conductive and thermally conductive. Graphene is also very strong, about 200 times stronger than the strongest steel and almost transparent. Being a 2D system, graphene also turns out to be an excellent way to test particle physics and relativity because of analogous features. With these properties, it’s not surprising that there has been an avalanche of research on graphene since its discovery.
Given its late discovery, one would expect graphene to be difficult to make, requiring clean rooms and extensive laboratory equipment, but this isn’t the case. In fact, graphene can be made in a variety of ways in very ordinary environments. This has led to a cottage industry of DIYers making and working with graphene. Although it is possible to create graphene in your home, it cannot be mass-produced. Although easy to make in small quantities, the processes involved are difficult to scale. Also, the graphene you create will not be very large, likely in the nanometer range in terms of length and width. Still, you can do a lot with a little graphene!
How To Make Graphene
One method of creating graphene is to use Scotch tape. This works by depositing graphite onto a paper using a pencil, then using the tape to peel a layer off the graphite on the paper. Then you can use another piece of tape to peel off a layer of graphite from the first tape, so on and so forth with new pieces of tape until you start getting single layers of graphene. If this method sounds absurd, keep in mind it is the method originally used by Giem and Novoselov to produce the first graphene.
Another method for creating graphene involves mixing heptane and distilled water into a glass, adding finely ground graphite powder, and sonicating. Since the heptane and water do not mix, there is an interface between them where the graphene forms, the graphene being more attracted to the heptane since they are both nonpolar molecules. The sonicating requires an ultrasonic bath, but these can be obtained fairly cheaply. The resulting graphene is one to several layers thick. You can retrieve it from the liquids using a glass slide.
Liquid shear exfoliation is another method of making graphene at home. For this, pour graphite powder into a blender with dish soap and water and mix at high speed for several minutes. Use a glass slide to remove the graphene. Again graphene will vary from single to multilayer sheets. This technique can be a bit finicky, since the amount of dish soap used depends on the amount of graphite powder and the variations in graphite size in the powder, but it has be demonstrated by researchers exactly as described. In fact, this method is considered a promising method for mass producing graphene, since it can scale and uses relatively cheap materials: water, graphite and a surfactant.
The Future of Graphene
Graphene has already been shown to be a remarkable material with impressive physical, thermal and electrical properties, but its market impact has been minimal because methods of manufacturing graphene only produce small amounts and don’t scale well. The DIY methods described above are not overly sophisticated from a chemistry standpoint. There is a massive potential market out there for the person or business that can develop a cheap way of manufacturing large amounts of graphene. Perhaps it will take a DIYer to develop to a cheap way to make graphene.