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.