scholarly journals Theoretical Investigation on the Solubilization in Water of Functionalized Single-Wall Carbon Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Michael Mananghaya ◽  
Emmanuel Rodulfo ◽  
Gil Nonato Santos ◽  
Al Rey Villagracia
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional ◽  
Dipole Moments ◽  
Binding Energies ◽  
Single Wall Carbon Nanotubes ◽  
Free Energies ◽  
Hydrogen Atoms ◽  
Water Dispersible ◽  
Aromatic Dicarboxylic Acid ◽  
Walled Carbon Nanotubes

An important technique to increase the solubility and reactivity of carbon nanotube is through functionalization. In this study, the effects of functionalization of some single-walled carbon nanotubes (SWCNTs) were investigated with the aid of density functional theory. The SWCNT model used in the study consists of a finite, (5, 0) zigzag nanotube segment containing 60 C atoms with hydrogen atoms added to the dangling bonds of the perimeter carbons. There are three water-dispersible SWCNTs used in this study that were functionalized with (a) formic acid, as a model of carboxylic acid, (b) isophthalic acid, as a model aromatic dicarboxylic acid, and (c) benzenesulfonic acid, as a model aromatic sulfonic acid. Binding energies of the organic radicals to the nanotubes are calculated, as well as the HOMO-LUMO gaps and dipole moments of both nanotubes and functionalized nanotubes. Binding was found out to be thermodynamically favorable. The functionalization increases the electrical dipole moments and results in an enhancement in the solubility of the nanotubes in water manifested through favorable changes in the free energies of solvation. This should lower the toxicity of nanotubes and improve their biocompatibility.

scholarly journals Theoretical Investigation on Single-Wall Carbon Nanotubes Doped with Nitrogen, Pyridine-Like Nitrogen Defects, and Transition Metal Atoms

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Michael Mananghaya ◽  
Emmanuel Rodulfo ◽  
Gil Nonato Santos ◽  
Al Rey Villagracia ◽  
Alvin Noe Ladines
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Properties ◽  
Density Functional ◽  
Strong Dependence ◽  
Topological Defects ◽  
Binding Energies ◽  
Single Wall Carbon Nanotubes ◽  
Functional Theory ◽  
Transition Metal Atoms ◽  
Walled Carbon Nanotubes

This study addresses the inherent difficulty in synthesizing single-walled carbon nanotubes (SWCNTs) with uniform chirality and well-defined electronic properties through the introduction of dopants, topological defects, and intercalation of metals. Depending on the desired application, one can modify the electronic and magnetic properties of SWCNTs through an appropriate introduction of imperfections. This scheme broadens the application areas of SWCNTs. Under this motivation, we present our ongoing investigations of the following models: (i) (10, 0) and (5, 5) SWCNT doped with nitrogen (CNxNT), (ii) (10, 0) and (5, 5) SWCNT with pyridine-like defects (3NV-CNxNT), (iii) (10, 0) SWCNT with porphyrine-like defects (4ND-CNxNT). Models (ii) and (iii) were chemically functionalized with 14 transition metals (TMs): Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag, Pt and Au. Using the spin-unrestricted density functional theory (DFT), stable configurations, deformations, formation and binding energies, the effects of the doping concentration of nitrogen, pyridine-like and porphyrine-like defects on the electronic properties were all examined. Results reveal that the electronic properties of SWCNTs show strong dependence on the concentration and configuration of nitrogen impurities, its defects, and the TMs adsorbed.

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

A DFT-D study on the interaction between lactic acid and single-wall carbon nanotubes

RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97724-97733 ◽  
Author(s):  
Alireza Najafi Chermahini ◽  
Abbas Teimouri ◽  
Hossein Farrokhpour
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Theory ◽  
Lactic Acid ◽  
Density Functional ◽  
Single Walled Carbon Nanotubes ◽  
Single Wall Carbon Nanotubes ◽  
Acid Molecule ◽  
Functional Theory ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Density functional theory (DFT) was used to investigate the adsorption of lactic acid molecule on the surface of (4,4), (5,5), (6,6) and (7,7) single-walled carbon nanotubes (SWCNTs).

Single-walled carbon nanotubes functionalized by a series of dichlorocarbenes: DFT study

2016 ◽  
Vol 30 (08) ◽  
pp. 1650118 ◽  
Author(s):  
Igor K. Petrushenko ◽  
Konstantin B. Petrushenko
Keyword(s):  
Carbon Nanotubes ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Young's Modulus ◽  
Strong Dependence ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

The structural and elastic properties of neutral and ionized dichlorocarbene (CCl2) functionalized single-walled carbon nanotubes (SWCNTs) were studied using density functional theory (DFT). The Young’s modulus of ionized pristine SWCNTs is found to decrease in comparison to that of neutral models. The interesting effect of increase in Young’s modulus values of ionized functionalized SWCNTs is observed. We ascribe this feature to the concurrent processes of the bond elongation on ionization and the local deformation on cycloaddition. The strong dependence of the elasticity modulus on the number of addends is also observed. However, the CCl2-attached SWCNTs in their neutral and ionized forms remain strong enough to be suitable for the reinforcement of composites. In contrast to the elastic properties, the binding energies do not change significantly, irrespective of CCl2 coverage.

scholarly journals Antimony Selenide Crystals Encapsulated within Single Walled Carbon Nanotubes-A DFT Study

2009 ◽  
Vol 6 (s1) ◽  
pp. S147-S152 ◽  
Author(s):  
Navaratnarajah Kuganathan
Keyword(s):  
Carbon Nanotubes ◽  
Binding Energy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Antimony Selenide ◽  
Walled Carbon Nanotubes

The structure and binding energies of antimony selenide crystals encapsulated within single-walled carbon nanotubes are studied using density functional theory. Calculations were performed on the simulated Sb2Se3structure encapsulated within single walled nanotube to investigate the perturbations on the Sb2Se3crystal and tube structure and electronic structure and to estimate the binding energy. The calculated structures are in good agreement with the experimental high resolution transmission electron microscopy images of the Sb2Se3@SWNT. The calculated binding energy shows that larger diameter tube could accommodate the Sb2Se3crystals exothermically. Minimal charge transfer is observed between nanotube and the Sb2Se3crystals.

Structures and Solid-Liquid Phase Transition of High-Density Hydrogen Confined in Single-Walled Carbon Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 67-70 ◽  
Author(s):  
Yue Yuan Xia ◽  
Ming Wen Zhao ◽  
Xiang Dong Liu ◽  
Yan Ju Ji
Keyword(s):  
Phase Transition ◽  
Carbon Nanotubes ◽  
Liquid Phase ◽  
Density Functional ◽  
Single Walled Carbon Nanotubes ◽  
Hydrogen Atoms ◽  
Liquid Phase Transition ◽  
Single Walled Carbon ◽  
Solid Liquid ◽  
Walled Carbon Nanotubes

Hydrogen with ultrahigh density confined in single-walled carbon nanotubes (SWCNTs) was investigated using density functional theory (DFT) and first principles molecular dynamics simulations (MDSs). Hydrogen atoms injected in to the cages of the SWCNTs via atomic collisions gradually form solid H2 molecular lattice with a characteristic of spiral multi-strands structure. The concentration of H2 confined in the SWCNTs can be as high as ~ 1.77×1023H2 /cm3, and the pressure between the H2 lattice and the wall of the SWCNT can be as high as ~ 77 GPa. When the system was heated to temperature higher than 700K, a solid-liquid phase transition was observed. When temperature rose to 1000K, a few H2 molecules dissociated forming a mixed liquid of H atoms, H2 molecules, and hydrogen trimers. Electron states near the Fermi level were appeared, which were attributed to the H atoms and the trimers. The electronic properties of the quasi-one-dimensional hydrogen confined in the SWNTs were thus substantially changed.

Corrections to the Optical Transition Energies in Single-Wall Carbon Nanotubes of Smaller Diameters

2004 ◽  
Vol 858 ◽  
Author(s):  
Georgii G. Samsonidze ◽  
Riichiro Saito ◽  
Jie Jiang ◽  
Alexander Grüneis ◽  
Naoki Kobayashi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Transition ◽  
Density Functional ◽  
Accurate Determination ◽  
Small Diameter ◽  
Binding Energies ◽  
Single Wall Carbon Nanotubes ◽  
Transition Energies ◽  
Single Wall Carbon ◽  
Electronic Transition Energies

ABSTRACTOptical spectroscopy characterization of carbon nanotube samples requires accurate determination of their band structure and exciton binding energies. In this paper, we present a non-orthogonal density-functional based tight-binding calculation for the electronic transition energies in single-wall carbon nanotubes. We show that the curvature-induced rehybridization of the electronic orbitals, long-range atomic interactions, and geometrical structure relaxation all have a significant impact on the electronic transition energies in the small diameter limit. After including quasiparticle corrections and exciton binding energies, the calculated electronic transition energies show good agreement with the experimental transition energies observed by photoluminescence and resonance Raman spectroscopy.

Density Functional Theory Calculations of Atomic Hydrogen Adsorption on (3, 3) Single-Wall Carbon Nanotubes with Vacancy Defects

2014 ◽  
Vol 687-691 ◽  
pp. 4315-4318
Author(s):  
Zong Sheng Li
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Theory ◽  
Hydrogen Atom ◽  
Density Functional ◽  
Single Wall Carbon Nanotubes ◽  
Adsorbed Hydrogen ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Single Wall Carbon

In this paper, we have employed density functional theory (DFT) to investigate the adsorption mechanisms of atomic hydrogens on the sidewalls of (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. All the calculations were performed using the generalized gradient approximation (GGA) with the Perdew, Burke and Ernzerhof (PBE) correlation functional.Our results show that hydrogen atoms can chemically adsorb on the defective nanotube. Bonding energy of per hydrogen atom decreases with the number of adsorbed hydrogen atoms. The hydrogen atoms will enhance the electrical conductivity of the (3, 3) nanotube. Besides one hydrogen atom adsorbing on the nanotube with a vacancy defect (MVD), hydrogen atoms move towards the MVD of the nanotube.

Effects of prenatal exposure to single-wall carbon nanotubes on reproductive performance and neurodevelopment in mice

2014 ◽  
Vol 32 (7) ◽  
pp. 1293-1301 ◽  
Author(s):  
Saeed Ivani ◽  
Isaac Karimi ◽  
Seyed Reza Fatemi Tabatabaei ◽  
Leila Syedmoradi
Keyword(s):  
Carbon Nanotubes ◽  
Prenatal Exposure ◽  
Motor Development ◽  
Behavioral Changes ◽  
Single Wall Carbon Nanotubes ◽  
Control Group ◽  
Plus Maze ◽  
Righting Reflex ◽  
Novel Drug ◽  
Walled Carbon Nanotubes

Carbon nanotubes with extraordinary properties may become a novel drug and gene delivery tool in nanomedicine; however, insufficient information is available regarding their biosafety. Therefore, this work was performed to study the effect of prenatal exposure of single-walled carbon nanotubes (SWCNTs) on reproductive and neurobehavioral endpoints in mice. Thirty pregnant female mice were assigned to three groups ( n = 10 for each group). The two treated groups were injected intraperitoneally (i.p.) with 1 or 10 mg/kg body weight (b.w.) of SWCNTs suspended in 1 ml of phosphate buffer saline (PBS) on gestational days 0 and 3. The control group was injected i.p. with an equal volume of PBS. The neurobehavioral ontogeny of pups was evaluated using a modified Fox battery. A decrease in litter size on postnatal day 2 was observed in the group treated with 10 mg/kg b.w. of SWCNTs whereas no significant differences between groups were observed in any other parameters. The behavioral development of pups did not show significant differences during growth except for the surface righting reflex, which showed significant delay compared to control in the group treated with 1 mg/kg b.w. SWCNTs. Moreover, exposed offspring (10 mg/kg b.w. SWCNTs) displayed enhanced anxiety in the elevated plus maze; however, other ethological analysis (Morris water maze and open field test) did not show behavioral changes in the experimental groups. In conclusion, the present results demonstrated small changes in offspring sensory and motor development following exposure to SWCNTs and support the idea that SWCNT risk assessment merits further investigation.

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