A novel protocol for precisely coating individual multiwall carbon nanotubes (MWCNTs) with an ultrathin layer of polypyrrole was developed. The nanocoated MWCNTs were successfully prepared by in situ chemical deposition of polypyrrole in an aqueous suspension of MWCNTs. The coating layer was very uniform and the thickness of the layer was determined by controlling the monomer concentration used...

Waste heat recovery with thermo-electrochemical cells is limited by their low power and conversion efficiencies. Here we explore ionic liquid electrolytes mixed with multiwall carbon nanotubes (MWCNTs) as alternative electrolytes for thermo-electrochemical cells. The results show that, upon addition of MWCNTs, the combination of interfacial polarization and ion pair dissociation reduces mass tr...

This research investigates changes in the nanostructure and the nanoscale local mechanical properties of cement paste with microand nano-modifiers. Silica fume and multiwall carbon nanotubes (MWCNTs) were used as microand nano-modifiers. An effective method of dispersing CNTs in cement matrix was developed. A detailed study on the effects of CNTs concentration and aspect ratio on the fracture p...

Rapid continuous thermal control of chemical reactions such as those for chemical vapor deposition (CVD) growth of nanotubes and nanowires cannot be studied using traditional reactors such as tube furnaces, which have large thermal masses. We present the design, modeling, and verification of a simple, low-cost reactor based on resistive heating of a suspended silicon platform. This system achie...

A Mg65Ni20Cu5Y10 metallic glass was produced by melt spinning and mixed with a 5 wt.% multiwall carbon nanotube additive in high-energy ball mill. Subsequently, the composite mixture exposed to high-pressure torsion deformation different numbers. Complimentary XRD DSC experiments confirmed exceptional structural thermal stability of amorphous phase against severe plastic deformation. Combined h...

The dc and ac electrical transport property of Polyvinyl Alcohol-Multiwall Carbon Nanotubes (PVA-MWNT) composites has been investigated within a temperature range 77≤T≤300K and in the frequency range 20Hz to 1MHz. The temperature variation of dc conductivity gives the presence of two different activation energies. The dielectric properties of the samples have been explained in terms of electric...

A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine thirteen pyrethroid insecticide residues in goat tissues (liver, kidney, muscle and heart) and milk using gas chromatography electron ionization mass spectrometry method (GC-MS). The samples were pre-concentrated using C18 packing material (dispersion adsorbent), followed by clean u...

We report the atomic-scale imaging with concurrent transport measurements of the breakdown of individual multiwall carbon nanotubes inside a transmission electron microscope equipped with a piezomanipulator. We found unexpectedly three distinct breakdown sequences: namely, from the outermost wall inward, from the innermost wall outward, and alternatively between the innermost and the outmost wa...

The growth of single wall carbon nanotubes (SWNTs) mediated by metal nanoparticles is considered within (i) the surface diffusion growth kinetics model coupled with (ii) a thermal model taking into account heat release of carbon adsorption-desorption on nanotube surface and carbon incorporation into the nanotube wall and (iii) carbon nanotube-inert gas collisional heat exchange. Numerical simul...

Multiwall CNx nanotubes have been prepared by thermal decomposition of acetonitrile over Co/Ni catalytic particles. The fluorination of nanotubes was performed at roomtemperature by using a gaseous mixture of BrF3 and Br2. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) indicated that only the outer shells of CNx nanotubes were fluorinated, whereas the inner shells remained i...