Beyond Graphene: New Nanomaterials For Solar Energy, Computers, Curing Cancer And A Lot More

Graphene has been theorized by scientists for decades, but it was only in 2004 that these atom-thin sheets of carbon (in the form of graphite) were isolated, leading to the two scientists responsible for the feat — Andre Geim and Konstantin Novoselov at the University of Manchester — being awarded the 2010 Nobel Prize in Physics. This material has many unusual properties that have excited researchers ever since it was isolated for its potential applications in fields as diverse as energy, electronics, medicine, sensors, light processing, and water filtration.

But science would be no good if it was content with what has been discovered over a decade ago, and scientists have been on the lookout for new nanomaterials that go beyond graphene. One such researcher who has been successful in this endeavor is Alexandra Boltasseva, a professor at the Purdue University, West Lafayette, Indiana. At the ongoing 4th International Conference on Quantum Technologies in Moscow, she sat down with International Business Times to talk about the work she is doing, and why it matters, starting with why it is important to not stop at graphene.

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“Lasers and optical fibers could have been invented long before they actually were. Everyone already knew how to guide light inside dielectrics, but it was only when people developed the right materials with the right set of properties and the right purity that we got internet connections between continents that allow us to Skype and use social media. It is the same sort of thing. In order to enable technologies, we ought to look in materials and see what new properties we can bring to the table. We appreciate and love graphene, and work with it, but that is not the end, it is just the beginning,” she said.

The work being done in Boltasseva’s laboratory at Purdue is not about replacing graphene entirely but also includes using it in combination with new materials she and her team are developing. Layering new materials (her lab is doing extensive work on using compounds of titanium, such as titanium nitride and titanium carbide) on top of graphene would combine their properties and “brings together the best of two worlds,” in her words. “Breakthrough and innovation happen at those interfaces.”

What, however, are these breakthroughs and their applications? Many, according to Boltasseva, some of which are already close to commercialization, such as memory storage in computer hard disks. Her lab had some interaction with companies like Seagate Technology, which has been trying to develop new materials for hard disks that are less susceptible to degradation due to heating. The company already holds patents on some of the same materials as produced in Boltasseva’s lab, which it developed on its own.

Another application of these new nanomaterials is in the field of plasmonics, where they can concentrate light at much smaller dimensions than any lens would. For instance, if you shine a laser light on an area only a few nanometers across, much of the energy from the light would be converted to heat. This can lead to localized heating, and this has real-world application in the field of biomedicine, specifically as a cancer treatment therapy, pioneered by Naomi Halas of Rice University, Houston, Texas.

Halas suggested using gold particles to kill cancer cells in the body by first putting those particles in the body and then heating them in locations next to the cancer cells, thereby burning cancer away. However, Boltasseva says the process can be done using the materials her lab is making, and that those materials have better heating efficiency, meaning smaller particles will need to be introduced in the body, and therefore be less toxic too. The same particles can also be used for targeted drug delivery.

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Solar energy is another field that stands to gain from these new titanium compounds. Thermal photovoltaic (TPV) devices made from these materials can absorb the entire spectrum of light, heating up to 1,500 degrees Celsius, a temperature that traditional TPV materials cannot withstand, at least not without reduced performance. A startup at Purdue that Boltasseva consults is working on building a system that uses both solar energy, as well as harnesses waste energy.

Sustainability, in terms of green energy production and improving the availability of clean water, is other areas that Boltasseva says her lab’s materials could be used for in the future, even though it is not her domain of expertise. But essentially, the titanium compounds (which are technically kinds of ceramic) can be used to split water to produce hydrogen, which can be used as a green fuel. On burning, it produces energy and clean water, thereby killing the two metaphorical birds with one ceramic stone.

On a somewhat less scientific note, Boltasseva hopes materials like titanium nitride or zirconium nitride (they resemble gold in appearance) will actually come one day to replace traditional metals used to make jewelry, especially since gold and silver are not just expensive, but are also often sourced from regions that are rife with conflict. However, these nitrides are really hard and there still need to be methods that can make them readily available to people to work with outside laboratories.

As a piece of additional trivia, Geim — one of the Nobel winners for his work on graphene — is so far the only person to have won both the prestigious science award as well as its parody equivalent, the Ig Nobel Prize, which he was given in 2000 for levitating a small frog with magnets, using the magnetic properties of water scaling. Geim and Novoselov are both graduates from the Moscow Institute of Physics and Technology, as is Boltasseva.