Raman spectra of single-wall carbon nanotubes ~SWCNTs! were measured at different temperatures by varying the incident laser power. The elevated temperature of the SWCNTs and multiwall carbon nanotubes ~MWCNTs! is confirmed to be due to the presence of impurities, defects, and disorder. The temperature coefficient of the frequency of the C–C stretching mode E2g ~GM! and that of the radial breat...

Dissociative adsorption has been widely simplified as part of the vapor–liquid–solid (VLS) growth model. We found that the addition of specific carrier gases can critically modify the growth rate and growth density of multiwall carbon nanotubes (MWNTs). These results were explained by dissociative adsorption of C2H2 molecules and a solid-core VLS growth model. Based on these integrated mechanis...

We have successfully prepared mono- and bi-functionalized multiwall carbon nanotubes (MWCNT) with thiophene, amine and thiophene-amine groups. The dispersion of nanotubes has been enhanced and stable optimized dispersions in organic solvents were obtained. These functionalized nanotubes have been successfully incorporated into bulk heterojunction (BHJ) organic photovoltaic (OPV) cells with a po...

Using total energy and structure optimization calculations, we investigate the relative stability and the conversion mechanism between multiwall carbon nanotubes and graphitic scrolls. We suggest that axial segments of a nanotube and a scroll may coexist within the same tubular nanostructure, separated by a dislocation region. A scroll may convert to the more stable nanotube by concerted bond-r...

Levedopa was sensitively determined based on electrogenerated chemiluminescence (ECL) mechanism through enhancing the weak ECL of electro-oxidized luminal in presence of levodopa, on a multiwall carbon nanotubes (MWCNTs)-modified electrode. Under optimal conditions, the relative ECL emission/levodopa concentration plot was found to be linear from 1.0×10-9 to 1.7×10-7 M and a detection limit of ...

A network of entangled multiwall carbon nanotubes is an assembly of non-bonded and randomly oriented units whose mechanical behavior is affected by their buckling, compression and slippage at contact points. Slippage and irreversible nanotube rearrangements are evidenced by the hysteresis in the stress-strain curves during loading and unloading cycles. To model the mechanical behavior, a nonlin...

In this paper functionalized multiwall carbon nanotubes (FMWCNT) were modified using doxycycline, containing reactable nitrogen, which can attach chemically to functionalized MWCNT. The synthesized nano compounds were characterized by Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. These spectrums proved the existence of nitrogen atoms of amide functional groups. The mor...