The strongest form of carbon fiber composite is being made right here at N.C. State.
The research paper, “Ultrastrong, Stiff and Multifunctional Carbon Nanotube Composites,” outlines the method by which N.C. State researchers created this new lightweight material and how it improves upon other carbon fiber composites.
Carbon fiber composite is a space-age material designed to be structurally strong and lightweight. It is most often used in aerospace constructions, like space shuttles and airplanes.
“If you are making a space shuttle, every pound of the weight costs hundreds of thousands of dollars to send into space,” explained Yuntian Zhu, a distinguished professor of materials science and member of the research team.
Carbon fiber composites originally replaced substances like aluminum to reduce the weight of planes in order to save fuel. The change to carbon fiber composites reduced fuel usage by about 20 percent.
Carbon fiber is traditionally made by taking thin filaments of carbon and weaving them into a kind of fabric, then pressurizing them into a plastic resin to hold them in shape. The result is an incredibly light, yet strong, solid material. Research has improved upon this carbon fiber material, making it stronger than ever by replacing the fibers with carbon nanotubes, or CNTs.
CNTs have been a focus of research for years due to certain theoretical properties which would make them very valuable, such as a high level of conductivity. While labs have not been able to create CNTs with these properties, they have been able to create ones structurally similar to the theoretical ideal. Researchers at N.C. State have taken these imperfect carbon nanotubes and created a way to use them to make carbon fiber composite.
The use of CNTs instead of traditional carbon fibers alters the properties. The CNTs have a simpler, stronger structure which gives the woven and resin-pressured fabric ultrastrong and stiff properties.
CNT composites also exhibit other properties that differentiate them from the standard carbon fiber composites. CNT composites have high degrees of electrical and thermal conductivities–and both of these properties are beneficial to use with aerospace technologies.
Thermal conductivity will make it easier for heat from plane engines pass through the hull and out into the surrounding air, making them easier to cool down. Electrical conductivity will make it safer for planes that find themselves in the middle of a thunderstorm, as lightning may simply pass through the hull leaving the plane unharmed. The research paper even hints that this may make CNT composites useful for solar energy collecting utilities, or photovoltaic panels.
The research is being primarily funded by the U.S. government for military purposes. The process created makes it easier for companies to produce high-performance CNT composite at a lower cost, but the research paper warns that variances in CNT length within the fibers may make it difficult to move to commercial production.
Stronger and lighter materials are always being made – but for now, the strongest and most efficient carbon fiber composite is credited to N.C. State and its researchers.
