Scattering of terahertz radiation from oriented carbon nanotube films

We report on the use of terahertz time-domain spectroscopy to measure scattering from multi-walled carbon nanotubes aligned normal to the film plane. Measurements indicate scattering from the nanotubes is significantly stronger than for bulk metal

Extreme magneto-transport of bulk carbon nanotubes in sorted electronic concentrations and aligned high performance fiber

We explored high-field (60T) magneto-resistance (MR) with two carbon nanotube (CNT) material classes: (1) unaligned single-wall CNTs (SWCNT) films with controlled metallic SWCNT concentrations and doping degree and (2) CNT fiber with aligned, long-length microstructure. All unaligned SWCNT films showed localized hopping transport where high-field MR saturation definitively supports spin polarization instead of a more prevalent wave function shrinking mechanism. Nitric acid exposure induced an insulator to metal transition and reduced the positive MR component. Aligned CNT fiber, already on the metal side of the insulator to metal transition, had positive MR without saturation and was assigned to classical MR involving electronic mobility. Subtracting high-field fits from the aligned fiber's MR yielded an unconfounded negative MR, which was assigned to weak localization. It is concluded that fluctuation induced tunnelling, an extrinsic transport model accounting for most of the aligned fiber's room temperature resistance, appears to lack MR field dependence

Aligned carbon nanotube reinforced high performance polymer composites with low erosive wear

The erosive wear behaviour of epoxy composites reinforced with aligned, as-produced carbon nanotube (CNT) films was investigated. The CNT film composites were fabricated in two different configurations, where the unidirectional (0°) and bi-directional (0°/90°) aligned CNT films were exposed to the particle stream. Results have shown that the unidirectional (0°) CNT film/epoxy composite exhibit superior erosive wear resistance compared to the unidirectional (0°) carbon fibre reinforced epoxy composite. Furthermore, the bi-directional (0°/90°) CNT film/epoxy composite shows even better resistance to erosion compared to the unidirectional (0°) CNT film/epoxy composite due to additional impact energy absorption resulted from CNT networks. Scanning Electron Microscopy (SEM) provides further insight into the erosive wear mechanisms of CNT film composites at different impingement angles. This work has successfully introduced aligned as-produced CNT films fabricating epoxy composites using traditional composite manufacturing processes with low erosive wear and high electrical performance which deliver potential for engineering applications