A $10 bet led to a breakthrough in production of the wonder material graphene. Thomas Mallouk, professor of chemistry, physics and biology at Penn State University, bet his research associate Nina Kovtyukhova that she could apply her research on boron nitrade to graphene. Kovtyukhova did not believe her methods would be effective to produce graphene so Mallouk made a wager – $100 to Kovtyukhova if she failed and $10 to Mallouk if she succeeded. The result? Mallouk is $10 richer and the proud owner of a post-it note complimenting his chemical intuition.
Graphene has been in the news almost constantly for the last few years. Every month brings new applications for this wonder material. It will revolutionize the way everything is made, but only if it can be produced in large enough quantities. Graphene is 200X stronger than steel while being 6X lighter. It also has an electron mobility 70X faster than silicon, used in computer processors, which makes it the most efficient conductor of electricity and heat. In addition, it is made of carbon which is an abundant element on earth. Carbon is special for its ability to bond in a multitude of ways to create diverse properties. Carbon makes up materials such as graphite, coal and diamond. As hard as a diamond, graphene can also be just as expensive to acquire.
Graphene can be used for a myriad of products. It can make smart phone and laptop screens that are thinner, flexible, waterproof, and indestructible. It could increase the efficiency of rechargeable electrovoltaic batteries and solar cells while decreasing the charging time. It can be used to build wind turbines, cars, planes and trains that are stronger and lighter. It even has medical applications in tissue regeneration and artificial retinas. It can create a super fast broadband internet that blows current speeds out of the water.
New research by Dr. Andre Geim and Dr. Rahul Nair revealed it is possible to introduce oxygen to the carbon sheets and create graphene oxide, a substance that can applied like paint to multiple surfaces. Painting glass or electronics can render them indestructible and impermeable. Lead author Dr. Yang Su says, “Thin layers of graphene paint are optically transparent,” and, “can be applied to practically any material, independently of whether it’s plastic, metal, or even sand.”
The key to all this amazing technology is the nanoscale of graphene. The carbon atoms are interlaced in sheets only one atom thick. Graphene is so thin it is considered two dimensional. This is also why graphene is difficult to produce. It is not easy to peel apart a substance one atom thick a layer at a time. Sometimes graphene is grown on a substrate and then peeled off through a multi-step process. Another way is to separate the layers of graphite into single-atom sheets of graphene.
The properties of graphene were discovered in 2004 by Konstantin Novoselov and Andre Geim who won the Nobel prize for essentially using sticky tape to peel off a layer of graphene from graphite, but their process can be costly and unreliable.
Another way to separate single layers is intercalation. Intercalation relies on other molecules which force their way between molecules of graphite separating it into sheets. Generally acids are used in conjunction with a strong oxidizing agenr. Intercalation has been around since the 1800s, but the oxidizing agent destroys the uniformity and quality of the graphene. In 1999 Nina Kovtyukhova developed the widely used method to intercalate graphite by oxidation.
Recently, Kovtyukhova has been experimenting with incalation of other layered substances without the oxidizing agent. She discovered that the reaction takes place and the layers of boron nitrade separate in the absence of the agent. However, all previous research indicated that the oxidizing agent was necessary for graphite so Kotyukhova was hesitant to take the time to experiment. Then Tom Mallouk placed his bet.
Kovtyukhova used Brønsted acids to move the fragile layers of graphene apart. The acids pushed in between the atoms of carbon but flat sheets of graphene remained intact. It successfully separated layers of graphite into graphene.The process needs to be refined before it can be used to industrial level production of graphene, but it is the first step. The Penn State team should work quickly because so far Europe leads the way in graphene research and a production breakthrough could come at any moment.
Many scientists and engineers are waiting with baited breath for the large scale production of graphene. Kovtyukhova’s discovery brings graphene one step closer. A $10 bet led to the breakthrough in production of this wonder material.
By: Rebecca Savastio