Agradecimentos: Authors acknowledge the funding support from the U.S. Department of Defense: the U.S. Air Force Office of Scientific Research for the Project MURI: "Synthesis and Characterization of 3-D Carbon Nanotube Solid Networks" Award No. etFA9550-12-1-0035. LDM and DSG acknowledge computational and financial support from the Center for Computational Engineering and Sciences at Unicamp through the FAPESP/CEPID Grant No. 2013/08293-7. LDM acknowledges financial support from the Brazilian Federal Agency CAPES via its PNPD program Ver menos

Abstract: Here, we report a highly scalable two-step method to produce graphene foams with ordered carbon nanotube reinforcements. In our approach, we first used solution assembly methods to obtain graphene oxide foam. Next, we employed chemical vapor deposition to simultaneously grow carbon nanotubes and thermally reduce the 3D graphene oxide scaffold. The resulting structure presented increased stiffness, good mechanical stability and oil absorption properties. Molecular dynamics simulations were carried out to further elucidate failure mechanisms and to understand the enhancement of the mechanical properties. The simulations showed that mechanical failure is directly associated with bending of vertical reinforcements, and that, for similar length and contact area, much more stress is required to bend the corresponding reinforcements of carbon nanotubes, thus explaining the experimentally observed enhanced mechanical properties Ver menos