Until recently, carbon dioxide (CO2) and carbon nanofibers had nothing in common except carbon. But now science has brought them together for the first time. Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities such as burning fossil fuels. Carbon nanofibers are one of the wonders of modern science, tiny fibers with a diameter so small they make a human hair look huge by comparison.
Solving two problems at once is one of the great joys of science. Until now, removing carbon dioxide from the air and manufacturing carbon nanofibers were both very expensive. But new research funded primarily by the National Science Foundation is changing all that. A research team led by Dr. Stuart Licht at George Washington University has found an inexpensive, energy-efficient chemical process to trap atmospheric carbon dioxide and use it to produce high-yield carbon nanofibers. This could convert carbon dioxide from a climate change problem into a valuable commodity.
The team has developed a chemical process which turns CO2 into nanofibers without expending much energy, because the entire process is powered by solar energy. The chemical process involves trapping the carbon dioxide in molten bath of electrolytes in which steel and nickel electrodes are immersed. The carbon dioxide breaks down and the nanofibers form on the steel electrodes when the molten bath is subjected to heat and an electrical current.
Solar power is applied to a pair of electrodes immersed in a mixture of molten lithium carbonate and lithium oxide. When air is pumped into the mixture, carbon dioxide from the air interacts with the lithium oxide and produces carbon nanofibers, oxygen, and more lithium carbonate. At the present time, the process has only been done on a small scale in the lab, but that is part of the normal process of developing a new technology. The next step is to increase the volume of air processed in order to make the process commercially viable.
But, the development cycle of this new process isn’t all that different from the development of the cell phone and the cell phone towers needed to support the cell phones. Prior to 1973, there were no cell phones and no cell phone towers. When Motorola introduced the first cell phone in 1973, it was an analog device that was big and heavy. You could only use it for 30 minutes before it had to be recharged, and recharging took ten hours. Twenty years later digital cell phones were introduced and the cell phone market expanded exponentially. Now cellphones are everywhere and people use them constantly.
Carbon nanofibers are incredibly strong and durable, and they have myriad uses. Nanofibers have been used to stimulate the production of new cartilage in damaged joints. By using Carbon nanofibers researchers have also developed an elastic balloon-like material that is inserted into a sick person’s body next to diseased tissue, and then inflated. When the balloon-like material inflates the carbon nanofibers penetrate the nearby diseased cells and deliver therapeutic drugs directly to the part of the body that needs them.
Scientists at MIT used carbon nanofibers to create lithium ion battery electrodes with four times the storage capacity of current lithium ion batteries. Scientists at Stanford are working on the development of lithium sulfur batteries which have even more storage capacity. Other researchers are using nanofibers to make sensors that change color when they are exposed to chemical vapors. These sensors will give a visual indication that the person wearing the sensor has been exposed to dangerous chemicals, and how much exposure they have had.
There are piezoelectric nanofibers that are flexible enough to be woven into clothing. These fibers turn normal motion into enough electricity to power a cell phone and other mobile electronic devices. You’ll be able to talk while you walk and not have to worry about recharging your phone. Flame retardant furniture has also been developed by coating the foam used in the furniture with carbon nanofibers.
But it is brutally expensive to produce nanocarbons, and that limits the size of the market. For example, one of most common methods of producing nanocarbons, catalytic chemical vapor deposition, requires heating the chemical bath to temperatures between 1000 and 1100 degrees Celsius. That’s 1800 to 2000 degrees Fahrenheit. It takes a lot of electrical power to heat the chemical bath to those temperatures, and that cost a lot of money, so there is a market for a less expensive method of producing nanocarbons,
In the short term, cleaning the air at the same time may be an added benefit to the manufacturers of nanocarbons, but in the long run that benefit may overshadow all the rest. Dr. Stuart Licht puts it this way, “We calculate that … our process could remove enough CO2 to decrease atmospheric levels to those of the pre-industrial revolution within 10 years.”