The mechanical properties of materials in small rod-shaped form are of considerable technological interest since, due to their shape and size, they can exhibit appreciably greater strength relative to corresponding macroscopic forms. For example, the mechanical strength of silicon carbide whiskers systematically increases with decreasing whisker diameter over the 100 to 1 micron range. This phe...

We present a theoretical study of the structure, local curvature angles, and reactivity of cap-ended (7,0), defective and nondefective carbon nanotubes. We find that the most reactive sites are the atoms that form part of the caps even when the Stone-Wales defect is present. Each carbon in the carbon nanotube is located at the top of a pyramidal structure with three walls of 5-, 6-, or 7-carbon...

Carbon nanotube sheets or films, also known as 'buckypaper', have been proposed for use in actuating, structural and filtration systems, based in part on their unique and robust mechanical properties. Computational modeling of such a fibrous nanostructure is hindered by both the random arrangement of the constituent elements as well as the time- and length-scales accessible to atomistic level m...

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...

Carbon nanotubes are becoming increasingly viable as membranes for application in a wide variety of nano-fluidic applications, such as nano-scale nozzles. For potential applications which utilise switching on and off of flow through nanotube nozzles, it is important to understand the initial flow dynamics. Furthermore, when the nanotube interacts strongly with the fluid, the flow may be very di...

Density-functional theory is used to investigate hydrogen physisorption on a graphene layer and on single wall carbon nanotubes. Both external and internal adsorption sites of 9, 0 and 10, 0 carbon nanotubes have been studied with the hydrogen molecular axis oriented parallel or perpendicular to the nanotube wall. A range of hydrogen molecule binding sites has been examined and it is found that...

first principles calculations were carried out for investigation the novel 7-hydroxycoumarinyl gallates derivatives in gas and liquid phases using density functional theory (dft) method. computational chemistry simulations were carried out to compare calculated quantum chemical parameters for gallates derivatives. all calculations were performed using dmol3 code which is based on dft. the doubl...

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...

We have studied the interaction of indomethacin and diclofenac solutions, on multi-walled carbon nanotube. After investigated comparative study and assigned to either indomethacin or diclofenac adsorption isotherms. The adsorption equilibrium isotherms were fitted by Freundlich, Langmuir, and Temkin models. It was found that the Freundlich model described the adsorption process better than othe...