The different arrangements and combinations in which carbon can exist produce a wide variety of compounds that have unique physical, chemical and electrical properties. Some of these allotropes behave as conductors while others are classified as semiconducting. Our efforts focused on taking advantage of the carbon-based materials’ potential and optimally we employed them together to form an all...

ABSRACT We have used a number of methods to grow long aligned single-walled carbon nanotubes. Geometries include individual long tubes, dense parallel arrays, and long freely suspended nanotubes. We have fabricated a variety of devices for applications such as multiprobe resistance measurement and high-current field effect transistors. In addition, we have measured conductance of single-walled ...

The single-walled nanotube (SWNT) is an interesting nanostructure for fundamental research and potential applications. However, very few inorganic SWNTs are available to date due to the lack of efficient fabrication methods. Here we synthesize four types of SWNT: sulfide; hydroxide; phosphate; and polyoxometalate. Each type of SWNT possesses essentially uniform diameters. Detailed studies illus...

We present a Raman spectroscopy study of iodine-intercalated (p-type doped) double-walled carbon nanotubes. Double-walled carbon nanotubes (DWCNTs) are synthesized by catalytic chemical vapor deposition (CCVD) and characterized by Raman spectroscopy. The assignment of the radial breathing modes and the tangential modes of pristine DWCNTs is done in the framework of the bond polarization theory,...

Strong quantum confinement and low dielectric screening impart single-walled carbon nanotubes with exciton-binding energies substantially exceeding kBT at room temperature. Despite these large binding energies, reported photoluminescence quantum yields are typically low and some studies suggest that photoexcitation of carbon nanotube excitonic transitions can produce free charge carriers. Here ...

We present theoretical and experimental studies of Schottky diodes that use aligned arrays of single-walled carbon nanotubes. A simple physical model, taking into account the basic physics of current rectification, can adequately describe the single-tube and array devices. We show that for as-grown array diodes, the rectification ratio, defined by the maximum-to-minimum-current-ratio, is low du...

A commercially available aliphatic thermoplastic polyurethane formulated with a methylene bis(cyclohexyl) diisocyanate hard segment and a poly(tetramethylene oxide) soft segment and chain-extended with 1,4-butanediol was dissolved in dimethylformamide and mixed with dispersed single-walled carbon nanotubes. The properties of composites made with unfunctionalized nanotubes were compared with the...

The thermal stability of nitrogen (N) functionalities on the sidewalls of N-doped multi-walled carbon nanotubes was investigated at temperatures ranging between 1000 °C and 2000 °C. The structural stability of the doped tubes was then correlated with the electrical conductivity both at the bulk and at the individual tube levels. When as-grown tubes were thermally treated at 1000 °C, we observed...

In this paper, the response surface methodology (RSM) and finite element (FE) simulation were applied to optimize push-bending process parameters of thin-walled tube with polyurethane mandrel. The objective present work is predict optimal set including length diameter ratio mandrel (L/D), friction coefficient between die ( $${\mu }_{1}$$ ), }_{2}$$ Poisson’s $$\upsilon$$ ) obtain qualified bent...

Crashworthiness studies are in high demand for designing transportation systems. Energy absorption capability in vehicle collisions is an important parameter for the development of passive safety systems dealing with the protection of passengers and cargo departments in the event of an accident. Protective structures, which contribute significantly to the crashworthiness capability of automotiv...