Multifunctional structural reinforcement featuring carbon nanotube films

Multiwalled carbon nanotube thin films were fabricated using catalytic chemical vapor deposition of xylene-ferrocene mixture precursor. The nanotube films were employed as inter-layers within composite systems to reinforce the interfaces between composite plies, enhancing laminate stiffness as well as structural damping. Experiments conducted using a piezo-silica composite beam with an embedded nano-film sub-layer indicated up to 200% increase in the inherent damping level and 30% increase in the baseline bending stiffness with minimal increase in structural weight. Scanning Electron Microscopy (SEM) characterization of the nano-film was also conducted to investigate the mechanics of stiffness and damping augmentation. The study revealed a fascinating network of densely packed, highly interlinked multiwalled nanotubes (MWNTs). This inter-tube connectivity resulted in strong interactions between adjacent nanotube clusters as they shear relative to each other causing energy dissipation within the nano-film. The cross-links between nanotubes also served to improve load transfer within the network resulting in improved stiffness properties. (C) 2003 Elsevier Ltd. All rights reserved.