Environmental Science 15th Edition by Scott Spoolman,Tyler Miller

Exercise 15

GRAPHENE: A REVOLUTIONARY MATERIAL
Graphene is made from graphite-a form of carbon that occurs as a mineral in some rocks. Ultrathin graphene consists of a single layer of carbon atoms packed into a two-dimensional hexagonal lattice (somewhat like chicken wire) that can be applied as a transparent film to surfaces (Figure 12.A).
Graphene is one of the world's thinnest and strongest materials and is light, flexible, and stretchable. A single layer of graphene is 150,000 times thinner than a human hair and 200 times stronger than structural steel. A sheet of this amazing material stretched over a coffee mug could support the weight of a car. It is also a good conductor of electricity and conducts heat better than any known material.
The use of graphene could revolutionize the electric car industry by leading to the production of batteries that can be recharged 10 times faster and hold 10 times more power than current car batteries. Graphene composites can also be used to make stronger and lighter plastics, lightweight aircraft and motor vehicles, flexible computer tablets, and TV screens as thin as a magazine. Within 5 years, it might also be used to make flexible, more efficient, less costly solar cells that can be attached to almost anything. Graphene could also replace the silicon transistors that are used as chips in computers and other electronic devices, and this could make almost any electronic device run much faster and use less power. Indeed, some scientists contend that the use of graphene will change the world more than any technological development since the invention of the silicon chip.
Graphene is made from very high purity and expensive graphite. According to the USGS, China controls about 73% of the world's high-purity graphite production. As with rare earth metals ( Core Case Study ), the United States mines very little natural graphite and imports most of its graphite from China, which may restrict U.S. product exports as the use of graphene grows.
Geologists are looking for deposits of graphite in the United States. However, in 2011, a team of Rice University chemists, led by James M. Tour, found ways to make large sheets of highquality graphene from inexpensive materials found in garbage and from dog feces. If such a process becomes economically feasible, concern over supplies of graphite could vanish, along with any harmful environmental effects of the mining and processing of graphite.

FIGURE 12.A Sheet of graphene, which consists of multiple layers of carbon atoms linked together in a hexagonal lattice, is a revolutionary new material.
Critical Thinking
Would you invest money in a company that mines and purifies graphite and converts it to graphene? Explain.