In order to accommodate an increasing demand for carbon nanotubes (CNTs) with desirable characteristics one has to understand the origin of helicity of their structures. Here, through in situ microscopy we demonstrate that the nucleation of a carbon nanotube is initiated by the formation of the carbon cap. Nucleation begins with the formation of a graphene embryo that is bound between opposite ...

The initial development of carbon nanotube synthesis revolved heavily around the use of 3d valence transition metals such as Fe, Ni, and Co. More recently, noble metals (e.g. Au) and poor metals (e.g. In, Pb) have been shown to also yield carbon nanotubes. In addition, various ceramics and semiconductors can serve as catalytic particles suitable for tube formation and in some cases hybrid metal...

The migration characteristics of carbon nanotubes from liquid phase to vapor phase in the refrigerant-based nanofluid pool boiling were investigated experimentally. Four types of carbon nanotubes with the outside diameters from 15 to 80 nm and the lengths from 1.5 to 10 μm were used in the experiments. The refrigerants include R113, R141b and n-pentane. The oil concentration is from 0 to 10 wt....

to investigate the interaction and adsorption of drug and carbon nanotube on human serum albumin, three anti-cancer drugs ([pd(phen)(r-gly)]no3, r = methyl, propyl and amyl) with different hydrophobic tails and anticancer activities were selected. these drugs have better anti-tumor activity and less side effects than that known cis-platinum drug. human serum albumin is also important for drug d...

The interacting induced dipole polarization model implemented in our program POLAR is used for the calculation of the dipole-dipole polarizability alpha. The method is tested with single-wall carbon nanotube models as a function of nanotube radius and elliptical deformation. The results for polarizability follow the same trend as reference calculations performed with our version of the program ...

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 ...

An achiral nematic liquid crystal was doped with a small quantity of carbon nanotubes, and the mixture was found to induce an average mechanical twist over macroscopic dimensions. The nanotube-induced chiral pitch length P was determined as a function of average nanotube concentration by measuring the radii of curvature of reverse twist disclination lines in 90° twisted nematic cells. The resul...

the interaction between some heavy metal ions such as of pb(ii), cd(ii) and cu(ii) ions from aqueous solution adsorbed by single walled carbon nanotube (swcnts) and carboxylate group functionalized single walled carbon nanotube (swcnt-cooh) surfaces were studied by atomic absorption spectroscopy. the effect of contact time, ph, initial concentration of ion, ionic strength and temperature on the...