Based on the continuum mechanics and a multiple-elastic beam model, the nonlinear free vibration of embedded multiwall carbon nanotubes considering intertube radial displacement and the related internal degrees of freedom is investigated. By using the incremental harmonic balanced method, the iterative relationship of nonlinear amplitude and frequency for the single-wall nanotube and double-wal...

We have carried out systematic calculations for hydrogen-adsorption and -storage mechanism in carbon nanotubes at zero temperature. Hydrogen atoms first adsorb on the tube wall in an arch-type and zigzag-type up to a coverage of theta = 1.0 and are stored in the capillary as a form of H(2) molecule at higher coverages. Hydrogen atoms can be stored dominantly through the tube wall by breaking th...

First-principles calculations based on density functional theory are carried out to investigate the Li storage capability of graphitic carbon nitride nanotubes. The porous nanotubes provide unprecedented opportunity for energy storage due to their uniform size of pores in the wall and doubly bonded nitrogen at the edges of the pore. The calculations predict that the Li atoms can easily access t...

Composites consisting of different quantities of carbon nanotubes and nanofibrils in a poly(methyl methacrylate) (PMMA) matrix have been prepared using a polymer extrusion technique. The nanotubes or nanofibrils were first dispersed over the polymer matrix particles using a dry powder mixing method. The final composite specimens contained well-dispersed and aligned nanofibrils and nanotubes. Th...

Unsteady flow of nanofluids squeezed between two parallel plates is discussed in the presence of viscous dissipation. Heat transfer phenomenon is disclosed via convective boundary conditions. Carbon nanotubes (single-wall and multi-wall) are used as nanoparticles which are homogeneously distributed in the base fluid (water). A system of non-linear differential equations for the flow is obtained...

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 ...

in this study, incorporation of iron ion-doped natrolite nanozeolite, multi-wall carbon nanotubes into chitosan-coated glassy carbon electrode for the simultaneous determination of ascorbic acid, epinephrine, uric acid and tyrosine is studied. the results show that the combination of multi-wall carbon nanotubes and iron ion-doped natrolite zeolite causes a dramatic enhancement in the sensitivit...

Molecular dynamics simulations are carried out to study the reorientation of single wall carbon nanotubes in a polyethylene matrix under the influence of a 25 T magnetic field. The simulations are based on a variant of velocity Verlet algorithm, which relaxes the Larmor time-step restriction while preserving second-order accuracy. Simulations reveal that the unfolding and reorganization of the ...

We propose a catalytic growth mechanism of single-wall carbon nanotubes based on density functional total energy calculations. Our results indicate nanotubes with an “armchair” edge to be energetically favored over “zigzag” nanotubes. We also suggest that highly mobile Ni catalyst atoms adsorb at the growing edge of the nanotube, where they catalyze the continuing assembly of hexagons from carb...

Carbon nanotubes are a new allotrope of carbon which emerged from the fullerene family [1]. Carbon nanotubes have been discovered by high resolution transmission electron microscopy (HRTEM) in 1991 by Iijima [2]. A single wall carbon nanotube is constituted of one atomic plane with a graphite-like arrangement of C atoms – called a graphene sheet – which is perfectly rolled into a cylinder (Fig....