Researchers at the UCLA Department of Engineering have developed novel carbon nanotube/resin composite material that dramatically enhances strength and toughness of carbon nanotubes.
Carbon nanotubes (CNTs) are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus, compared to steel and Kevlar at a fraction of the weight. CNTs superior strength is a result of their unique cylindrical nanostructure of carbon molecules. In order to harvest these unique properties of CNTs for commercial applications, CNTs and their composites must be processed in a cost efficient and scalable way. Researchers have attempted to incorporate CNTs into inexpensive, lightweight resins, by directly infusing resins into mats of carbon fibers, or performing chemistry on the surface of the CNTs to make them more compatible with current resin. However, in the latter method, resins often cannot penetrate the nano/microporous air pockets within the CNT yarns, and the resulting carbon fiber/resin composite materials are not able to achieve the strength of carbon fiber or Kevlar.
Researchers at UCLA have developed a novel CNT/resin composite material that approaches the strength of Kevlar at a lighter weight. This new method involves compounding thousands of CNTs into a single unit CNT yarn on the millimeter scale, followed by surface chemistry performed on the CNT yarn to allow for resin compatibility, and infusion of resin by a Vacuum Assisted Resin Transfer Molding (VARTM) process. This method can drastically reduce the viscosity of the resin and allow it to fully permeate in between the CNTs within the yarn. The resulting CNT/resin composite has a superior weight/strength ratio than that of materials such as steel, aluminum, Kevlar, and carbon fibers, and thus has the potential to replace these materials in the automotive and aeronautic industry.
|United States Of America||Issued Patent||8,470,946||06/25/2013||2011-132|