Highly Conductive, Super Stiff Carbon Nanotube-based Macroassemblies and Their Composites

M.A. Worsley, S.O. Kucheyev, J.D. Kuntz, T.Y-J. Han, J.H. Satcher Jr, A.V. Hamza, T.F. Baumann
Lawrence Livermore National Laboratory, US

Keywords: carbon nanotube, polymer, metal oxide, composite

Summary:

Potential applications for nanoporous solids are often limited by their notoriously poor mechanical and electrical properties at low densities. The simultaneous display of remarkable properties by individual carbon nanotubes (CNT) and their light weight make them excellent candidates as building blocks for low-density nanoporous solids. Many attempts have been made to realize these individual CNT properties on a macroscopic scale, but with only weak VdW forces to crosslink CNTs, the final structures are typically fragile at low densities. Here we show a method to fabricate ultralow-density (as low as ~10 mg/cc) CNT aerogels that simultaneously exhibit high electrical conductivities and robust mechanical properties. These CNT-based aerogels are the stiffest low-density nanoporous solids reported and exhibit elastic behavior up to strains as large as ~80%. The use of graphitic crosslinks allows bulk electrical conductivity to be maintained at low densities resulting in order of magnitude improvements compared to aerogels without carbon nanotubes. Our results show that multiple properties of individual CNTs can be realized in low-density bulk structures if the appropriate crosslinking agent is used. Details of the aerogel and composite characterization will be discussed in comparison with theory and literature.