Science

Wonder Material Graphene Recycled from Trash

High voltage jolts of electricity could turn large sources of carbon into graphene, used in electronics, solar panels, asphalt and more.

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Within the honeycomb layers of graphene lies great potential to disrupt current industries or even to launch entirely new ones. Graphene boasts an impressive list of superlatives: it is 200 times stronger than steel but has incredible lightness, it has an impressive thermal conductivity of 3000-5000 W/mK, and it is the first 2D material ever produced that is thinner than the width of a human hair.

These qualities make graphene incredibly useful for a variety of industrial and research-oriented applications. For example, the Samsung Advanced Institute of Technology found that coating lithium ion batteries in graphene increased their capacity while reducing their charging speed by up to 500 percent. Similarly, graphene may also revolutionize the production of solar cells—though the graphene-lined cells were found to be slightly less efficient than aluminum solar cells, their flexibility and lightness opens many new avenues of potential expansion for solar cell installation.

Besides its solar power applications, graphene could be used to create “heavy water”: water that contains a higher-than-average concentration of the hydrogen isotope deuterium. Such water is used to cool nuclear reactors in power plants. Heavy water needs a sizable amount of resources to create; furthermore, it emits up to 9.64 tons of greenhouse gases per gigawatt hour. The introduction of graphene would do much to mitigate both issues.

Industrially, a graphene concentration of 0.1 percent in concrete would lessen the environmental impact of concrete production by almost a third. Considering that cement production accounts for eight percent of human carbon dioxide emissions, the potential gains are huge. In the medical field, graphene could deliver chemotherapeutic drugs to tumors. Alternatively, it could be used to induce autophagy—the removal of dysfunctional cells from the body—as graphene oxide was found to induce apoptosis in cancer cells when applied to the tumor. It could even eliminate incorrect DNA altogether, as studies have demonstrated that graphene can induce translocation of DNA segments.

Unfortunately, up until now, these experiments were almost impossible to bring to life in marketable products. Originally, an adhesive was used to strip thin layers of graphene from high quality graphite, but the technique was error-prone and inefficient for mass production. Such imperfections have stymied the commercial adoption of graphene for years.

However, a relatively simple manufacturing process recently discovered by Professor James Tour at Rice University may finally be bringing graphene to a wider market. The procedure is able to turn reasonably sized chunks of any carbon-based material into valuable flakes of graphene by heating it to unbelievably high temperatures via electric pulses.

The newly dubbed ‘flash’ graphene, so named because the excess energy from the reaction is released in a flash of light, is actually made in just a flash—10 milliseconds, to be exact. The heat in the process, reaching up to 3000 degrees Fahrenheit, speeds up the geological evolution of carbon into graphite, stopping at the graphene stage. The process is known as ultrafast time-resolved and angle-resolved photoemission spectroscopy (trARPES); Tour hopes that it will be able to create 2.2 pounds of graphene each year.

The flash graphene is actually turbostratic, meaning that its layers are not aligned with each other. This makes the extremely fine sheets of graphene much easier to work with and pull apart. Hydrocarbons from oil and gas can be repurposed into graphene, not only reducing greenhouse gas emissions but also using once untapped carbon to our advantage.

However, the flash graphene has not been tested for imperfections or drawbacks yet, so we should be wary lest flash graphene turns out to be as dangerous as asbestos proved. Economic questions for this process have not yet been raised in this early stage, but as scientists get to understand the uses and manufacture of graphene better, they will play a large factor in its introduction to society. As previously mentioned, graphene has the capability to disrupt and perhaps even make certain industries obsolete, which surely those businesses will fight tooth-and-nail against. Moreover, questions of patents and governmental regulation are problems that must be considered soon, just as they were for other revolutionary technologies upon being introduced to the market, like gene editing and electricity.

Though dreams and speculation of future use of this seemingly wondrous material seem far from reality, with time and more research, graphene could become a staple in our society, whether in flexible, light solar cells grafted to our clothes, in cancer treatments, in nuclear power plants, or in industrial manufacture. The widespread use of graphene would be akin to the introduction of plastic. This time, however, it seems like the new material will be saving turtles rather than killing them.