Concrete may have found it's killer app in graphene. Concrete is just dirt and water, but its properties make it a wonderful building material. Graphene is one atom thick and one-atom-wide. What would happen if you made an entire building out of graphene? That's the plan of a company called Triton, which aims to develop concrete made entirely from graphene. Graphene is a tough substance, capable of withstanding incredible pressures, making it perfect for use in things like aircraft landing gears. Now graphene can be found on its own, but a graphene-concrete bridge could be in our future. How Graphene is Made Graphene is a single layer of carbon, with a hexagonal lattice structure. But, making graphene is not easy. In a single-layered sheet of graphite, each atom is bonded to three others, with a very strong force. If you cut this sheet of graphite, you would see three separate sheets of graphene. They're called the top layer, the second layer and the third layer. But, cutting a single sheet into pieces destroys the lattice structure, ruining graphene. You can make a more stable version of graphene by sandwiching two layers of graphite between two sheets of boron nitride. This material is called graphene-boron nitride. You can also make stable graphene by heating a graphite rod in the presence of hydrogen. This process creates a sheet of graphene. Unfortunately, it’s unstable. The graphene atoms lose their lattice structure, destroying its strength. So, unless you want to break and destroy your graphene, try these different techniques to get started. Making Graphene You can't just go to the store and buy graphene, so you'll have to make it yourself. Making it on a Graphite Sheets The first thing you need to do is to make graphene on graphite. You have to start with a graphite rod, one-and-a-half inches long and about one-eighth-inch in diameter. You heat the graphite rod, then rotate it slowly at around 1,600 degrees F. You’ll notice that it will begin to oxidize, turn brown and look like wood. It should keep rotating for about three to four hours, when you're ready to take the rod out. When you cool it down, it's ready to be put on an insulated metal frame. You can make more graphene sheets by doing this process over and over. Making Graphene on Boron Nitride Graphite is a bad base material to make graphene sheets on. Luckily, there's another material that has no problem making graphene sheets. Boron nitride is another atom-thick, single layer of carbon. It has a hexagonal lattice structure, much like graphene, but it’s harder. You start with a boron nitride powder. The mixture needs to be spread over a heating plate. The powder will slowly turn to a blackish color. You let the temperature of the plate reach 1,800 degrees F for about 30 minutes. You cool the sample down and remove it from the heat. You repeat this process several times, until the boron nitride turns brownish, turning to diamond and releasing its carbon atoms to form graphene. Growing Graphene on a Graphene-Boron Nitride You can create a single layer of graphene on a boron nitride film, but if you want to make several layers of graphene you need to go back to the graphite. You need a few things, the first being a graphite rod. The second are a boron nitride sheet and a silicon wafer. The third is a piece of silicon dioxide, used to make a silicon wafer, which you can get from silicon dioxide. You'll also need a piece of a glass microscope slide. You'll also need to have some acetone. First, you will spread some graphite powder on the glass slide. This will act as a base for the graphene. You spread the graphite on a flat surface, until it becomes dry. You use an acetone and cover the entire surface of the slide. You then use a rubber spatula to spread the graphite and boron nitride onto the silicon wafer. You wait about two hours to let the graphene settle. Then, you apply acetone to the surface of the glass and scrape off the graphene. You will repeat the process with the other two graphene sheets. This is to ensure you have only a single layer of graphene on the surface. Storing Graphene You can keep your graphene for as long as you like, as long as you don't mess with it. Graphene keeps its structure and properties up to 2,000 degrees. If you find yourself with too much graphene, you can put it on boron nitride. Both materials will help keep the graphene stable. Making a Graphene Fiber Now, we know how to make graphene and graphene-boron nitride, but where can you get it? You may have seen these materials on the surface of a spacecraft. They're called graphene-boron nitride composites. These things are amazing and very strong. They're just one atom thick and as strong as diamond. The strength comes from the way they are laid out. Graphene is a flat sheet. When you put it on a boron nitride sheet, the resulting material has graphene as its surface. These fibers are the strongest composites around. These were made using graphene-boron nitride. You can get graphene on a roll. You’ll find it in the form of thin sheets on the surface of a roll of BN. You can get these sheets of graphene in various places. You can buy them in a company in California, called Graphit Inc. These sheets can be used to make aircraft parts and more, like carbon fibers and steel fibers. Graphene's Uses Graphene is very good at a lot of things. It can withstand heat and pressure that no other material can. It can be used for everything from batteries to building structures. It can also be used as a transparent conductor. When you apply a voltage to graphene, you can see the current. Graphene can also be used to separate contaminants in water. You can use it to make more efficient solar panels. You can use it for the filtration of air or water. It can be used as an additive in plastics or cement. It can be used as a building block in the construction of batteries. It can even be used as a catalyst for fuel cells. The Future of Graphene If graphene is so good at a lot of things, why isn't it in everything? Cost If it costs $20,000 to make a single transistor, why are they still making them from silicon? The answer is that silicon is cheaper than graphene. You can get sheets of graphene that are cheaper than you can buy them. There’s also a lot of potential in graphene. The price of graphene could keep dropping, as the volume of graphene needed to make a specific product goes down. Material Sizing Graphene can be used in very small places. It can also be used to make things of very different sizes. If you take a large enough piece of graphene, it can take you all the way from our solar system to the edge of the universe. Smaller pieces of graphene can be used for much smaller areas. For instance, you could use them to create a battery that's the size of a grain of sand. Safety This is a key component of any material you put into use. Graphene can be made in a way that makes it very safe. It can also be made in a way that is completely safe. It can also be used to make very safe electronics. You can't make electronics with diamond or silicon, as they're really hard, can damage the human body and are too difficult to handle. Graphene can be made in a way that is completely safe. It's made of carbon, which is found in a number of naturally occurring minerals. It can also be made from a safe compound, boron nitride. Using Carbon Nanotubes and Carbon Nanofibers in Concrete The Future of Concrete You might not realize it, but your concrete could be using a little bit of graphene. Graphene is so good at a lot of things, that you can imagine making something out of it in our concrete. A graphene-concrete bridge. A high-pressure tank. A high-tech battery. A high-tech transistor. If a few things can be made using graphene, then all of our concrete can. Graphene-concrete isn't far off. It's the future of concrete. This article is part of the Topical Collection This material is based upon work supported by the National Science Foundation under Grant Number DMR-0820341. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This material is based upon work supported by the National Science Foundation under Grant Numbers DMR-0820341 and DMR-1507483. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.