Properties Modeling of Low-Dimensional Carbon Nanostructures

2011 ◽  
Vol 1284 ◽  
Author(s):  
Andrew Basteev ◽  
Leonid Bazyma ◽  
Mykhaylo Ugryumov ◽  
Yuriy Chernishov ◽  
Margarita Slepicheva
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanostructures ◽  
Single Wall Carbon Nanotubes ◽  
Wall Structure ◽  
Simulation Algorithm ◽  
Simulation Procedure ◽  
Event Driven ◽  
Thermodynamic Conditions ◽  
Low Dimensional ◽  
Theoretical Results

ABSTRACTThe modeling of single wall carbon nanotubes properties (length, diameter, chirality, defective wall structure) influence on sorption capability at different thermodynamic conditions (T= 80-273 К; P = 2-12 MPa) is presented in this work. The applied simulation procedure is the molecular dynamics as well the new event-driven simulation algorithm has been used. In the frameworks of this event-driven simulation algorithm the modeling of structure formation for carbon nanotubes have been done with different chirality and with wall defects presence. The analysis of obtained results and their comparison with published experimental and theoretical results are performed.

Pressure Isotherms of Hydrogen Adsorption in Carbon Nanostructures

2001 ◽  
Vol 706 ◽  
Author(s):  
Xiaohong Chen ◽  
Urszula Dettlaff-Weglikowska ◽  
Miroslav Haluska ◽  
Martin Hulman ◽  
Siegmar Roth ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Activated Carbon ◽  
Hydrogen Storage ◽  
Carbon Nanostructures ◽  
Room Temperature ◽  
Storage Capacity ◽  
Hydrogen Adsorption ◽  
Single Wall Carbon Nanotubes ◽  
Hydrogen Storage Capacity ◽  
Carbon And Graphite

AbstractThe hydrogen adsorption capacity of various carbon nanostructures including single-wall carbon nanotubes, graphitic nanofibers, activated carbon, and graphite has been measured as a function of pressure and temperature. Our results show that at room temperature and a pressure of 80 bar the hydrogen storage capacity is less than 1 wt.% for all samples. Upon cooling, the capacity of hydrogen adsorption increases with decreasing temperature and the highest value was observed to be 2.9 wt. % at 50 bar and 77 K. The correlation between hydrogen storage capacity and specific surface area is discussed.

scholarly journals Biocompatibility and Biomechanical Effect of Single Wall Carbon Nanotubes Implanted in the Corneal Stroma: A Proof of Concept Investigation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Alfredo Vega-Estrada ◽  
Joaquin Silvestre-Albero ◽  
Alejandra E. Rodriguez ◽  
Francisco Rodriguez-Reinoso ◽  
Jose A. Gomez-Tejedor ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanostructures ◽  
Corneal Stroma ◽  
Collagen Fibers ◽  
Single Wall Carbon Nanotubes ◽  
Corneal Tissue ◽  
Safe Procedure ◽  
Biomechanical Effect ◽  
Active Inflammation

Corneal ectatic disorders are characterized by a progressive weakening of the tissue due to biomechanical alterations of the corneal collagen fibers. Carbon nanostructures, mainly carbon nanotubes (CNTs) and graphene, are nanomaterials that offer extraordinary mechanical properties and are used to increase the rigidity of different materials and biomolecules such as collagen fibers. We conducted an experimental investigation where New Zealand rabbits were treated with a composition of CNTs suspended in balanced saline solution which was applied in the corneal tissue. Biocompatibility of the composition was assessed by means of histopathology analysis and mechanical properties by stress-strain measurements. Histopathology samples stained with blue Alcian showed that there were no fibrous scaring and no alterations in the mucopolysaccharides of the stroma. It also showed that there were no signs of active inflammation. These were confirmed when Masson trichrome staining was performed. Biomechanical evaluation assessed by means of tensile test showed that there is a trend to obtain higher levels of rigidity in those corneas implanted with CNTs, although these changes are not statistically significant (p>0.05). Implanting CNTs is biocompatible and safe procedure for the corneal stroma which can lead to an increase in the rigidity of the collagen fibers.

In-situ Observations of Restructuring Carbon Nanotubes via Low-voltage Aberration-corrected Transmission Electron Microscopy

2011 ◽  
Vol 1284 ◽  
Author(s):  
Felix Börrnert ◽  
Alicja Bachmatiuk ◽  
Sandeep Gorantla ◽  
Jamie H. Warner ◽  
Bernd Büchner ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Carbon Nanostructures ◽  
Low Voltage ◽  
Single Wall Carbon Nanotubes ◽  
Structure And Dynamics ◽  
Transmission Electron ◽  
Aberration Corrected

ABSTRACTThe molecular structure and dynamics of carbon nanostructures is much discussed throughout the literature, mostly from the theoretical side because of a lack of suitable experimental techniques to adequately engage the problem. A technique that has recently become available is low-voltage aberration-corrected transmission electron microscopy. It is a valuable tool with which to directly observe the atomic structure and dynamics of the specimen in situ. Time series aberration-corrected low-voltage transmission electron microscopy is used to study the dynamics of single-wall carbon nanotubes in situ. We confirm experimentally previous theoretical predictions for the agglomeration of adatoms forming protrusions and subsequent removal. A model is proposed how lattice reconstruction sites spread. In addition, the complete healing of a multi-vacancy consisting of ca. 20 missing atoms in a nanotube wall is followed.

Studies on the Preparation and Characterisation of Carbon Nanostructures

2004 ◽  
Vol 99-100 ◽  
pp. 269-272
Author(s):  
R.J. Kalenczuk ◽  
E. Borowiak-Palen ◽  
T. Pichler ◽  
M. Rümmeli ◽  
J. Fink
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanostructures ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Single Wall Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
New Class ◽  
Chemically Modified ◽  
Transmission Electron

We present a study on the preparation of multiwalled carbon nanotubes (MWCNT) using chemical vapour deposition (CVD). The CVD produced MWCNT and single wall carbon nanotubes (SWCNT) produced with a laser ablation technique were then chemically modified by substituting carbon atoms with boron and nitrogen atoms. The morphology and the crystal structure of the new class of nanostructures were analyzed by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Anisotropy in the Phonon Dispersion Relations of Graphite and Carbon Nanotubes Measured by Raman Spectroscopy

2002 ◽  
Vol 737 ◽  
Author(s):  
Georgii G. Samsonidze ◽  
Riichiro Saito ◽  
Ado Jorio ◽  
Antonio G. Souza Filho ◽  
Alexander Grüneis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Phonon Dispersion ◽  
Double Resonance ◽  
Single Wall Carbon Nanotubes ◽  
Resonance Theory ◽  
Phonon Spectra ◽  
Device Use ◽  
Low Dimensional

ABSTRACTThe possible semiconducting device use of single wall carbon nanotubes (SWNTs) requires a technique for the determination of the exact structure of the nanotubes assembled in the device configuration. Raman spectroscopy has been established as a precise and non-destructive tool for the characterization of graphitic nanostructures. Double resonance theory, which is used to explain the dispersive nature of the Raman bands, has attracted much attention for its potential use for the characterization of the electronic and phonon spectra of these nanostructures. Dispersive features in the Raman spectra of low dimensional graphitic materials, such as carbon nanotubes, can be used to measure directly the anisotropy, or the trigonal warping effect, in the phonon dispersion relations about the hexagonal corner of the Brillouin zone (BZ) of graphite.

Direct Observation Of Iodine Atomic Chains In I-Doped Carbon Nanotubes

1999 ◽  
Vol 5 (S2) ◽  
pp. 144-145
Author(s):  
X. Fan ◽  
E.C. Dickey ◽  
S.J. Pennycook ◽  
L. Grigorian ◽  
P.C. Eklund ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Density Functional ◽  
Linear Chain ◽  
Single Wall Carbon Nanotubes ◽  
Contrast Imaging ◽  
Nanotube Bundles ◽  
Atomic Chains ◽  
Low Dimensional ◽  
Z Contrast

Single wall carbon nanotubes (SWNT) were doped with iodine, resulting in charge transfer between the iodine and carbon [1]. It was found that the iodine intercalation is air stable and also reversible by simple heat treatment. This behavior is in contrast to graphite and fullerenes which do not form charge transfer compounds with iodine. Although the iodine-induced charge transfer was not found in any other carbon polymorph solid, it has been found in some low dimensional organic polymers such as polyaniline,[2] forming charged linear-chain polyiodides (I3)- and (I5)-. This suggests that the geometric configuration of the carbon may play a very important role in iodine intercalation. In this study, we use Z-contrast imaging[3] in a VG Microscopes HB603U STEM to directly observe the configuration of iodine within the nanotube bundles. First-principles density-functional calculations are then used to explain the preference for the observed iodine configuration within the nanotubes.

Thermal and Thermoelectric Measurements of Low Dimensional Nanostructures

2003 ◽  
Author(s):  
Choongho Yu ◽  
Wanyoung Jang ◽  
Tobias Hanrath ◽  
Dohyung Kim ◽  
Zhen Yao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Thermoelectric Measurements ◽  
Improved Design ◽  
Sno2 Nanobelts ◽  
Low Dimensional

Low dimensional materials have unique thermal and thermoelectric properties that can be very different from their bulk counterparts. In a previous work, we and our collaborators have developed a microdevice for measuring thermal and thermoelectric properties of multiwall carbon nanotubes. Here, we used an improved design of the device for measuring single wall carbon nanotubes, Ge nanowires, and SnO2 nanobelts. These nanostructures are trapped between two adjacent symmetric silicon nitride membranes of the micro device using either a wet deposition method or in-situ chemical vapor deposition. The measurements provide the critically needed data of the unique thermophysical properties of these nanomaterials.

scholarly journals Carbon Nanotubes and its Application in Nanotechnology

2021 ◽  
pp. 1-4
Author(s):  
RC Jagessar ◽  
Keyword(s):  
Carbon Nanotubes ◽  
Materials Science ◽  
Van Der Waals Interactions ◽  
Single Wall Carbon Nanotubes ◽  
Wall Structure ◽  
Weakly Bound ◽  
End Effects ◽  
Single Wall Carbon ◽  
Multi Wall Carbon Nanotubes ◽  
The Individual

Carbon nanotubes often refer to single-wall carbon nanotubes (SWCNTs) with diameters in the range of a nanometer. Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate between fullerene cages and flat graphene. Carbon nanotubes also often refer to multi-wall carbon nanotubes(MWCNTs), consisting of nested single-wall carbon nanotubes, weakly bound together by van der Waals interactions in a tree ring-like structure. If not identical, these tubes are very similar to long straight and parallel carbon layers, cylindrically arranged around a hollow tube. Multi-wall carbon nanotubes are also sometimes used to refer to double and triple wall carbon nanotubes. Carbon nanotubes can also refer to tubes with an undetermined carbon wall structure and diameters less than 100 nanometers. While nanotubes of other compositions exist, most research has been focused on the carbon ones. The length of a carbon nanotube produced by common production methods is typically much larger than its diameter. Thus, for many purposes, end effects are neglected and the length of carbon nanotubes is assumed infinite. Carbon nanotubes can exhibit remarkable unique properties. These include electrical conductivity, while others are semiconductors. They also have exceptional tensile strengthand thermal conductivity, because of their nanostructure and strength of the bonds between carbon atoms. In addition, they can be chemically modified. Thus, due to their variable, unique properties, carbon nanotubes have found applications in many realms such as electronics, optics, composite materials nanotechnology, and other applications of materials science. In addition, carbon nanotubes can be integrated into other molecules to form novel structures with unique properties, different from the individual reactants. These unique products have also found application in many realms of nanotechnology

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