For decades, carbon fiber has been the core material used in aircraft and automobile production. If made in the right way, these long chains of atoms longer than carbon (thinner than human hair) will be light, hard, and strong, which is ideal for ensuring the safety of passengers in high-flying aircraft.
Generally speaking, the cost of manufacturing carbon fiber is very expensive. A group of researchers said that a new method of manufacturing carbon fiber-by adding a small amount of graphene to the production mixture, may one day lead to the use of these lightweight, high-strength materials to improve safety and reduce the production of cars cost.
The research team combined computer simulation and laboratory experiments and found that adding a small amount of 2D graphene during the production process can not only reduce production costs, but also enhance the fiber.
Adri van Duin, a professor of mechanical and chemical engineering at Pennsylvania State University, said: "Even if carbon fiber does have a good function, they will make cars more expensive according to the current carbon fiber manufacturing method. "" If you make these properties easier to manufacture, you can make the car significantly reduce weight, reduce costs and improve safety. "
Currently, the market price of carbon fiber is about $ 15 per pound. The team (including researchers from Pennsylvania State University, the University of Virginia and Oak Ridge National Laboratory) collaborated with industry partners Solvay and Oshkosh, hoping to reduce the price of carbon fiber to $ 5 per pound by changing complex production processes Achieve this goal.
The lower production cost will undoubtedly help to fully explore the potential application of carbon fiber in the field of automobile manufacturing. In addition, the team ’s research may also help reduce the cost of producing other types of carbon fiber, some of which currently cost up to $ 900 per pound.
Magorzata Kowalik, a researcher at the Department of Mechanical Engineering at Pennsylvania State University, said: "At present, most carbon fibers are produced from a polymer called polyacrylonitrile (or PAN), and the cost is very high." "The price of PAN About 50% of the cost of carbon fiber production. "
90% of the carbon fibers on the market today are made with PAN, but the production of this polymer consumes a lot of energy. First, PAN fibers must be heated to 200-300 ° C to oxidize. Next, they must be heated to 1200-1600 ° C to convert the atoms into carbon. Finally, they must be heated to 2100 ° C in order to arrange the molecules correctly. Without this series of steps, the resulting material will lack its required strength and stiffness.
The research team reported in the latest issue of "Science Advances" (Science Advances) that a small amount of graphene (concentration by weight, only 0.075%) is added in the first stage of the process. The strength is 225% higher than standard carbon fiber, and the stiffness is 184% higher than standard carbon fiber. The thesis is titled "Graphene reinforced carbon fibers".
The team conducted a series of small and large-scale computer simulations on several supercomputers and the advanced network infrastructure of the Institute of Computing and Data Science (ICDS), collected observation data on accompanying chemical reactions, and studied each Material characteristics.
Van Duin, director of the MRI Materials Computing Center and ICDS employee, said: “We link experiments of different scales, not only to show that the process is effective, but also provide us with reasons for the role of such additives at the atomic scale.”
The flat structure of graphene helps to arrange PAN molecules uniformly throughout the fiber, which is necessary in the production process. In addition, at high temperatures, graphene edges have natural catalytic properties, so "the rest of the PAN will condense around these edges."
Using the new knowledge gained from this research, the team is exploring ways to further use graphene in the production process using cheaper precursors, with the goal of reducing one or more production steps, thereby further reducing costs.