Fracture Nucleation in Single-Wall Carbon Nanotubes Under Tension: A Continuum Analysis Incorporating Interatomic Potentials

2002 ◽  
Vol 69 (4) ◽  
pp. 454-458 ◽  
Author(s):  
P. Zhang ◽  
Y. Huang ◽  
H. Gao ◽  
K. C. Hwang
Keyword(s):  
Carbon Nanotubes ◽  
Continuum Theory ◽  
Single Wall Carbon Nanotubes ◽  
Great Promise ◽  
Interatomic Potentials ◽  
Bifurcation Instability ◽  
Continuum Analysis ◽  
Set Up ◽  
Walled Carbon Nanotubes ◽  
Fracture Nucleation

Carbon nanotubes show great promise for applications ranging from nanocomposites, nanoelectronic components, nanosensors, to nanoscale mechanical probes. These materials exhibit very attractive mechanical properties with extraordinarily high stiffness and strength, and are of great interest to researchers from both atomistic and continuum points of view. In this paper, we intend to develop a continuum theory of fracture nucleation in single-walled carbon nanotubes by incorporating interatomic potentials between carbon atoms into a continuum constitutive model for the nanotube wall. In this theory, the fracture nucleation is viewed as a bifurcation instability of a homogeneously deformed nanotube at a critical strain. An eigenvalue problem is set up to determine the onset of fracture, with results in good agreement with those from atomistic studies.

Studies of Energy and Mechanical Properties of Single-Walled Carbon Nanotubes via Higher Order Cauchy Born Rule

2007 ◽  
Vol 121-123 ◽  
pp. 1029-1032
Author(s):  
J.B. Wang ◽  
X. Guo ◽  
Hong Wu Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Continuum Theory ◽  
Single Walled Carbon Nanotubes ◽  
Higher Order ◽  
Interatomic Potentials ◽  
Born Rule ◽  
Graphite Sheet ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Brenner Potential

Based on the higher order Cauchy-Born rule, a nanoscale finite deformation continuum theory, which links interatomic potentials and atomic microstructure of carbon nanotubes to a constitutive model, is presented for analysis of the mechanics of carbon nanotubes. By using of Tersoff-Brenner potential with two sets of parameters, the energy and Young’s modulus of graphite sheet and single-walled carbon nanotubes are studied based on the theory presented. The findings are in good agreement with the existing experimental and theoretical results.

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.

A Finite-Temperature Continuum Theory Based on Interatomic Potentials

2005 ◽  
Vol 127 (4) ◽  
pp. 408-416 ◽  
Author(s):  
H. Jiang ◽  
Y. Huang ◽  
K. C. Hwang
Keyword(s):  
Temperature Dependence ◽  
Finite Temperature ◽  
Interatomic Potential ◽  
Coefficient Of Thermal Expansion ◽  
Harmonic Approximation ◽  
Continuum Theory ◽  
Single Wall Carbon Nanotubes ◽  
Interatomic Potentials ◽  
Atomistic Models ◽  
Continuum Theories

There are significant efforts to develop continuum theories based on atomistic models. These atomistic-based continuum theories are limited to zero temperature (T=0K). We have developed a finite-temperature continuum theory based on interatomic potentials. The effect of finite temperature is accounted for via the local harmonic approximation, which relates the entropy to the vibration frequencies of the system, and the latter are determined from the interatomic potential. The focus of this theory is to establish the continuum constitutive model in terms of the interatomic potential and temperature. We have studied the temperature dependence of specific heat and coefficient of thermal expansion of graphene and diamond, and have found good agreements with the experimental data without any parameter fitting. We have also studied the temperature dependence of Young’s modulus and bifurcation strain of single-wall carbon nanotubes.

scholarly journals Nanostructures and their application in antimicrobial drug delivery system

2017 ◽  
Vol 4 (1-4) ◽  
pp. 81-90
Keyword(s):  
Carbon Nanotubes ◽  
Noble Metals ◽  
Antimicrobial Properties ◽  
High Reactivity ◽  
Great Promise ◽  
Antimicrobial Drugs ◽  
Microbial Inhibition ◽  
Carbon Based Nanomaterials ◽  
Walled Carbon Nanotubes

As multiresistant and pan-resistant infections continue to emerge, and because the development of novel antimicrobial drugs is a slow process, nanotechnology offers valuable alternatives for fighting resistant bugs, mainly by improving the therapeutic effect of current antimicrobials. Antibiotic resistance is one of the greatest global health threats of the 21st century, but nanotechnology is offering new solutions to the problem. Nanostructured biomaterials, nanoparticles in particular, have unique physicochemical properties such as ultra small and controllable size, large surface area to mass ratio, high reactivity, and functionalizable structure. These properties can be applied to facilitate the administration of antimicrobial drugs, thereby overcoming some of the limitations in traditional antimicrobial therapeutics. Carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles) show potent antimicrobial properties. Nanocoating and shuttle systems have shown great promise in vitro and animal models. Noble metals nanostructures, particularly silver, have attracted much attention in the fields of medicine due to their unique properties which are strongly dependent on the size and shape of metal nanomaterials. Recent development of nanocarriers, improved the drug therapy of different diseases, together with the mechanisms of microbial inhibition.

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).

Molecular Dynamics Simulation of Bi-Carboxyl Sidewall Functionalized Single-Wall Carbon Nanotubes in Water

2015 ◽  
Vol 1131 ◽  
pp. 106-109
Author(s):  
Shongpun Lokavee ◽  
Chatchawal Wongchoosuk ◽  
Teerakiat Kerdcharoen
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Single Wall Carbon Nanotubes ◽  
First Principles Calculations ◽  
Carboxylic Groups ◽  
Potential Applications ◽  
Walled Carbon Nanotubes ◽  
Defective Sites

Functionalized single-walled carbon nanotubes (f-SWNTs) have attracted great interest due to their enhancement of SWNT properties leading to an increase in potential applications beyond those of pristine SWNT. In this work, we have investigated the behavior of open-end (9,0) bi-carboxyl sidewall functionalized SWNTs in water using molecular dynamics (MD) technique within GROMACS software package based on the OPLS force fields with modified charges obtained from the first principles calculations. The model tubes including perfect and defective nanotubes covalently functionalized by bi-carboxylic groups on different sidewall surface orientation were fully optimized by B3LYP/6-31G(d,p). The simulations were performed at the constant volume and temperature in a rectangular box with periodic boundary conditions in which each system contains one model tube and ~1680 water molecules. The results form MD simulations showed that functionalization on the central carbon atom in the (C1,C ́1)SW-defective sites strongly affects on the dynamic behavior of CNT in water. Results showed that the hydrophilic behavior of the functionalized SWNT has been improved over the pristine and defective nanotubes.

Cutting Single Wall Carbon Nanotubes

1999 ◽  
Vol 593 ◽  
Author(s):  
I. Stepanek ◽  
G. Maurin ◽  
P Bernier ◽  
J. Gavillet ◽  
A. Loiseau
Keyword(s):  
Carbon Nanotubes ◽  
Nitrogen Adsorption ◽  
Diamond Powder ◽  
Single Wall Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Micrographs ◽  
Transmission Electron ◽  
Breaking Mechanism ◽  
Oxidation In Air ◽  
Walled Carbon Nanotubes

ABSTRACTIn this contribution, we report on a mechanical method to cut and open single walled carbon nanotubes. This technique is based on using an abrasive material (diamond powder) without any chemical treatments or oxidation in air at high temperature. We present highresolution transmission electron microscopy micrographs, which show firstly that the tubes are unambiguously opened and secondly, that the nanotubes have not suffered the treatment. x-ray diffraction pattern confirms a well-defined bundle organisation. A breaking mechanism of the nanotube bundles is proposed. Nitrogen adsorption measurements at 77K reveal the presence of new microporosities ranging in the average nanotube diameter, which confirm the opening of some tubes.

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