In this study, titanium oxide nanotubes anodized on threedifferent surface morphologies of titanium foils, were investigated. AFM imagesis used to show different surface roughness of these foils. Nanotubes wereanodized on titanium foils with 1) no polishing process (A sample), 2)electropolishing process (B sample) and 3) electropolishing process in ethanolicelectrolyte (C sample). To study the ...

In this paper, multi-walled carbon nanotubes are synthesized by arcdischarge and chemical vapor decomposition methods. Multi-walled carbon nanotubes are synthesized on thin film of nickel sputtered on silicon substrate by thermal chemical vapor deposition of acetylene at a temperature of 750°C. The flow of current in arc-discharge method varies in the range 50–200 A. Further arcsynthesized carb...

The synthesis of inorganic nanotubes (INT) from layered compounds of a small size (<10 nm in diameter) and number of layers (<4) is not a trivial task. Calculations based on density functional tight-binding theory (DFTB) predict that under highly exergonic conditions, the reaction could be driven into a “window” of (meta-) stability, where 1–3-layer nanotubes will be formed. Indeed, in this stu...

One-dimensional nanotube systems with high surface-to-volume ratios possess unique properties and are thus utilized in various applications. In this study, self-organized TiO2 nanotubes were prepared by anodization of a Ti foil in glycerol containing 5 wt% ammonium fluoride (NH4F) and 6 wt% ethylene glycol (EG). The surface morphology, average inner diameter, and average length of the nanotubes...

Since the last decade, research activities in the area of nano-materials have been increased dramatically. More than a 1000 of journal articles in this area have been published within the last 3 years. Materials scientists and researchers have realized that the mechanical properties of materials can be altered at the fundamental level, i.e. the atomic-scale. Carbon nanotubes (hereafter called ‘...

One of the critical issues for the application of single-wall carbon nanotubes (SWCNTs) in nanoelectronics is the control of their electronic properties, which can be either metallic or semiconducting in their pristine form, depending on their diameter and chirality. Since all known preparative methods yield mixtures of metallic and semiconducting nanotubes, extensive research has been devoted ...

the physical adsorption of hydrogen sulfide and carbon dioxide gases on the zigzag (5,0) carbon nanotubes doped with nitrogen was investigated through the application of b3lyp/6-31g* at the level of theory on gaussian 03 software. a variety of stable and high abundance structures of nitrogen doped carbon nanotubes were considered in order to study the interaction between the mentioned gases in ...

The emergence of carbon nanotubes (CNTs) has stimulated considerable interest in investigating their physical and mechanical properties toward the development of potential technological applications. It has been confirmed theoretically and experimentally that nanotubes possess remarkably high stiffness and strength. Carbon nanotubes also have exceptionally high electrical and thermal conductivi...

Fluorescence has been observed directly across the band gap of semiconducting carbon nanotubes. We obtained individual nanotubes, each encased in a cylindrical micelle, by ultrasonically agitating an aqueous dispersion of raw single-walled carbon nanotubes in sodium dodecyl sulfate and then centrifuging to remove tube bundles, ropes, and residual catalyst. Aggregation of nanotubes into bundles ...

We report total-energy electronic-structure calculations that provide energetics and electronic structures of double-walled carbon nanotubes consisting of semiconducting (n,0) nanotubes. We find that optimum spacing between the walls of the nanotubes is slightly larger than the interlayer spacing of the graphite. We also find that the electronic structures of the double-walled nanotubes with th...