This essay is the fourth in the series Drexel students write about Drexel innovations
by Mark Santella
During his most recent State of the Union address, President Barack Obama talked about how American needs to once again be a leader in innovation, especially in the fields of science and technology. There are constant advancements made every day in the world of science and technology. It is in places like Drexel University that these progresses are made. One of the most current and innovative areas of technology is the area of nanotechnology. Amongst the different parts of nanotechnology one of the more interesting sections of research is carbide-derived carbons. A carbide-derived carbon is a nanostructured carbon material that is made from some sort of metal carbide, like Titanium carbide (TiC) or Silicon carbide (SiC) (Dash). These carbon structures have many different applications, all of which are extremely useful in today’s world (Presser). These applications include everything from supercapacitors and batteries to the storage of methane and hydrogen gases.
The use of carbon derived carbons and their functions as supercapacitors are very important to the continued use of batteries and other portable charge-holding devices. Supercapacitors are akin to both capacitors and batteries, and share characteristics of each. Activated carbons are usually used due to the high surface area they provide for capacitance. While batteries use chemicals to store the energy to provide power, supercapacitors use a purely mechanical means of storing energy. This physical mechanism allows for a much greater life compared to nowadays batteries, in the realm of more than a thousand times longer (Presser). These supercapacitors are somewhat of a balance between the tradeoffs on batteries and normal capacitors. They offer a higher amount of power than a normal battery but inferior to that of a standard capacitor. This is traded off by the fact that the supercapacitor can store more energy than a conventional capacitor but less than that of a standard battery (Presser). Two approaches were made in the formation of the supercapacitors from carbide-derived carbons. One was a strengthened pyrocarbon composite and the other was mixing CDC powder with some form of a binder to hold it together and then formed into micro-meter films (Yushin). The powder based capacitors have been found to be much more effective, with a much larger capacitance than most other carbon based structures (Yushin). Another bonus that the supercapacitors have over other means of storing electrochemical energy is that their effectiveness does not wane as much over time, with little appreciable decay in effective capacitance after the ten thousandth full cycle of charging and discharging (Dash). These new innovations in the field of energy storage are important to the future of humanity. Most current high-power batteries of today have a shorter lifetime, require narrow ranges of temperature in order to function efficiently, and are extremely unhealthy for the environment (Yushin). Especially with the recent green “revolution” that has been sweeping the world making batteries, whose waste is highly pollutive and corrosive, a good choice for making environmentally friendly.
Another useful application for these carbon structures is the storage of methane and hydrogen gases. This is a useful innovation in that both methane and hydrogen are useful sources of energy but containing large enough quantities for the amount of gas to be useful, yet not occupy such a large volume that it becomes unfeasibly large and bulky. There have been a few proposed manners in which to store hydrogen a few of the involving sorption. Any of the processes that involve sorption, which is the action of either absorption or adsorption, require some form of highly porous material in order to give the highest amount of surface area over which the sorption can occur (Yushin). It also must allow for the hydrogen to be easily taken in and released from the material. Depending on the specific parameters that are set before deriving a carbon structure from some metal carbide, the characteristics of the CDC can be changed in order to best fit the function that it is being produced for (Presser). In this case the CDC can be optimized to be extremely porous and have pores that are optimized to fit the maximum amount of gas in them, be it hydrogen or methane. The efficient storage of both methane and hydrogen gases are highly important innovations. In order for hydrogen to ever become a legitimate fuel source it will require the development of material like the ones described above; a material with a high enough storage capacity yet without being too expensive. This is beneficial to the planet again as hydrogen is a constantly renewable source of energy and gives off little to now pollution, its only byproduct being water. With methane there is potential for it to be used as a substitute for gasoline in automotive in the future as the global reserves of natural gas far exceeds that of the oil reserves (Yushin). Methane based engines are also cheaper, cleaner, and require less maintenance than your average gasoline engine. The only problem at the moment is finding a way to store methane that allows for a comparable driving distance before refueling as compared to gasoline (Presser). The storage of gases will continue to be an issue until some material, which could potentially be a CDC, is developed that allows for cheap, efficient storage of hydrogen and methane.
Innovations are important to the future of mankind and CDCs will probably hold a space there for a long time. The development of more advanced CDCs will lead to greater technologies and the ability to do far more than we can achieve right now. These nano-structured compounds are indescribably small but the impact that they pose to have on the world is on a massive scale, on par with some of the great inventions of the world and Drexel University is one of the leading research centers for it. There will continue to be great innovations in the future and these advances will shape the future of this planet for years to come.
Dash, Ranjan. “Titanium carbide derived nanoporous carbon for energy-related applications.” Carbon44.12 (2006): 2489-97. Web. 22 Feb 2011.
Presser, Volker. “Carbide Derived Carbons (CDC).” A.J. Drexel Nanotechnology Institute. Drexel University, 2009. Web. 23 Feb 2011.
Yushin, G. "Carbide-Derived Carbon." Nanomaterials Handbook. Ed. Gogotsi, Yuri. Philadelphia: Drexel University, 2006. Web.