The term “nanocarbon” refers to carbon-derived materials that have at least one dimension at the nanoscale, a few billionths of a meter or a few tens of thousands of times smaller than the diameter of a human hair. Quintessential examples include fullerenes (soccer ball–shaped molecules that are at the nanoscale in all three dimensions), carbon nanotubes (rolled up sheets of carbon atoms, long in one dimension but with a diameter at the nanoscale), and graphene (a single-nanometer-thick sheet of carbon atoms). These materials are at the center of attention of research in nanoscience and nanotechnology, fields in which Penn State is a nationally and globally recognized leader with expert scientists, world-class instrumentation, and cutting-edge capabilities in novel nanomaterials synthesis and characterization as well as nanoscale fabrication of novel devices.
The various forms of nanocarbon provide a way to take a well-understood, simple atom as the building block for nanoscale structures whose properties could be tailored with exquisite precision. Much of the fascination with carbon nanomaterials initially arose because matter at the nanoscale can behave in fundamentally different ways than we commonly experience in the quotidian world. For instance, the wave-like behavior of electrons that arises from quantum physics becomes more readily manifest in nanomaterials, allowing us to design, fabricate, and measure new types of quantum technologies, such as single-electron transistors. Indeed, much of the initial excitement about nanocarbon was driven by physicists, materials scientists, and device engineers who sought to exploit these nanomaterials for quantum devices that might form the backbone of nanoelectronics. The particular bonding arrangement of carbon atoms in nanotubes also gives them exceptional mechanical properties, making them the stiffest and strongest materials known. Despite many fundamental scientific breakthroughs in our understanding of nanocarbon, practical applications of carbon nanoelectronics and carbon nanomechanical structures have yet to be realized. However, researchers have been pursuing many other imaginative applications of these nanomaterials. In this issue, we highlight two research programs that are advancing the frontiers of this exciting field into unexplored territory and continuing a long tradition of world-class research in carbon at Penn State.
The first article describes research from Mauricio Terrones’s group on bioengineering applications of carbon nanotubes. Here, instead of trying to exploit the esoteric ideas of quantum science, the Terrones group exploits a much more physically immediate aspect of these nanostructures: They use the nanoscale dimensions of nanotubes as a means of creating physical barriers and traps for viruses. The article describes how Terrones and his group have devised protocols for synthesizing “forests” of nanotubes that are tailored to capture viruses of specific size ranges. Not content with constraining their fundamental science to the lab, they are also translating their discovery into a practical technology that could have enormous impact for field detection and analysis of viruses.
The second article focuses on research that is still very much in the fundamental realm. A trio of Penn State researchers—John Badding, Elizabeth Elacqua, and Vin Crespi—has been advancing the synthesis and understanding of a completely new form of nanocarbon known as a carbon nanothread. The nature of the carbon-carbon bonds makes this nanocarbon a closer relative of diamond than of the other forms of nanocarbon discussed earlier. It is a fascinating story that shows how creative theoretical predictions from condensed matter theory can guide skilled materials chemists toward the creation of completely new artificial materials that nature cannot produce of its own accord. Where these new “super nanomaterials” will lead us is anyone’s guess, but it is easy to bet big on the science and technological potential waiting to be unlocked by this new discovery.