A bstract. Detailed growth mechanism of single-wall nanotube bundles and of multiwall nanotubes of carbon is investigated using ab initio and parametrized calculations. Our results show that single-wall tubes grow only in presence of a catalyst, whereas multi-wall tubes, stabilized at the growing edge by a covalent "lip-lip" interaction, may form in a pure carbon atmosphere. The individual tube...

We report in situ environmental transmission electron microscope observations of the nucleation and growth of multi-wall and single-wall carbon nanotubes formed by the catalytic decomposition of acetylene (C2H2) on Ni/SiO2 catalyst. The growth rate, structure and morphology of the carbon nanotubes formed depended upon reaction temperature and pressure. Under 20-100 mTorr of gas pressures at 480...

The present paper focuses on numerical study for an inclined magneto-hydrodynamic effect on free convection flow of a tangent hyperbolic nanofluid embedded with Carbon nanotubes (CNTs) over a stretching surface taking velocity and thermal slip into account. Two types of nanoparticles are considered for the study; they are single and multi-walled nanotubes. The presentation of single-parameter g...

Angiogenesis is vital for tumour formation, development and metastasis. Recent reports show that carbon nanomaterials inhibit various angiogenic signalling pathways and, therefore, can be potentially used in anti-angiogenic therapy. In the present study, we compared the effect of different carbon nanomaterials on blood vessel development. Diamond nanoparticles, graphite nanoparticles, graphene ...

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....

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...

volumetric techniques were employed to study the adsorption of co2 on a purified multi-wall carbon nanotubes (mwnt’s) sample, as a mesoporous material, at isothermal conditions of 288, 293 and 298 k and pressures ranging from 30 to 150 kpa. langmuir, freundlich and sips equations were used to represent the isotherms. also the parameters of these fitted isotherm models have been determined. the ...

the electrochemical oxidation and determination of tryptophan (trp) and glutathione (gsh) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (mwcnt-cpe) using cyclic voltammetry (cv), double step potential chronoamperometry and differential pulse voltammetry (dpv) techni...

Uniform dispersion of pre-synthesized nanotubes in metal matrices is difficult to achieve, and there is substantial damage to the nanotubes during subsequent composite fabrication. The demonstration of an in-situ process involving chemical vapor deposition of single-wall and multi-wall carbon nanotubes into iron matrices without the concomitant formation of iron carbides is reported here. It wa...

multifunctional nanomaterials showed graet advantages in drug delivery. folic acid (fa) binding protein, a glycosyl phosphatidyl inositol anchored cell surface receptor for folate, is overexpressed in several human tumors, whereas it is highly restricted in normal tissues. therefore, in this study, fa, polyethylene glycol (peg), and fe3o4 nanoparticles multifunctionalized short multiwall carbon...