scholarly journals Macroscopic Ensembles of Aligned Carbon Nanotubes in Bubble Imprints Studied by Polarized Raman Microscopy

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Shota Ushiba ◽  
Jordan Hoyt ◽  
Kyoko Masui ◽  
Junichiro Kono ◽  
Satoshi Kawata ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Microscopy ◽  
Single Wall Carbon Nanotubes ◽  
Coffee Ring ◽  
Aligned Carbon Nanotubes ◽  
Wide Range ◽  
Optical Applications ◽  
Polarized Raman ◽  
Short Time ◽  
Opening Up

We study the alignment of single-wall carbon nanotubes (SWCNTs) in bubble imprints through polarized Raman microscopy. A hemispherical bubble containing SWCNTs is pressed against a glass substrate, resulting in an imprint of the bubble membrane with a coffee ring on the substrate. We find that macroscopic ensembles of aligned SWCNTs are obtained in the imprints, in which there are three patterns of orientations: (i) azimuthal alignment on the coffee ring, (ii) radial alignment at the edge of the membrane, and (iii) random orientation at the center of the membrane. We also find that the alignment of SWCNTs in the imprints can be manipulated by spinning bubbles. The orientation of SWCNTs on the coffee ring is directed radially, which is orthogonal to the case of unspun bubbles. This approach enables one to align SWCNTs in large quantities and in a short time, potentially opening up a wide range of CNT-based electronic and optical applications.

Biological Interactions of Functionalized Single-Wall Carbon Nanotubes in Human Epidermal Keratinocytes

2007 ◽  
Vol 26 (2) ◽  
pp. 103-113 ◽  
Author(s):  
Leshuai W. Zhang ◽  
Liling Zeng ◽  
Andrew R. Barron ◽  
Nancy A. Monteiro-Riviere
Keyword(s):  
Carbon Nanotubes ◽  
Cell Viability ◽  
Single Wall Carbon Nanotubes ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Single Wall Carbon ◽  
Biological Compatibility ◽  
Tnf Α ◽  
Wide Range ◽  
Significant Difference

Carbon nanotube–based nanovectors, especially functionalized nanotubes, have shown potential for therapeutic drug delivery. 6-Aminohexanoic acid–derivatized single-wall carbon nanotubes (AHA-SWNTs) are soluble in aqueous stock solutions over a wide range of physiologically relevant conditions; however, their interactions with cells and their biological compatibility has not been explored. Human epidermal keratinocytes (HEKs) were dosed with AHA-SWNTs ranging in concentration from 0.00000005 to 0.05 mg/ml. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability decreased significantly ( p < .05) from 0.00005 to 0.05 mg/ml after 24 h. The proinflammatory mediators of inflammation cytokines interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)- α, IL-10, and IL-1 β were also assessed. Cytokine analysis did not show a significant increase in IL-6 and IL-8 in the medium containing 0.000005 mg/ml of AHA-SWNTs from 1 to 48 h. IL-6 increased in cells treated with 0.05 mg/ml of AHA-SWNTs from 1 to 48 h, whereas IL-8 showed a significant increase at 24 and 48 h. No significant difference ( p < .05) was noted with TNF- α, IL-10, and IL-1 β expression at any time point. Transmission electron microscopy of HEKs treated with 0.05 mg/ml AHA-SWNTs for 24 h depicted AHA-SWNTs localized within intracytoplasmic vacuoles in HEKs. Treatment with the surfactant 1% Pluronic F127 caused dispersion of the AHA-SWNT aggregates in the culture medium and less toxicity. These data showed that the lower concentration of 0.000005 mg/ml of AHA-SWNTs maintains cell viability and induces a mild cytotoxicity, but 0.05 mg/ml of AHA-SWNTs demonstrated an irritation response by the increase in IL-8.

scholarly journals Functionalization of vertically aligned carbon nanotubes

2013 ◽  
Vol 4 ◽  
pp. 129-152 ◽  
Author(s):  
Eloise Van Hooijdonk ◽  
Carla Bittencourt ◽  
Rony Snyders ◽  
Jean-François Colomer
Keyword(s):  
Carbon Nanotubes ◽  
Surface Characteristics ◽  
High Carbon ◽  
Vertically Aligned Carbon Nanotubes ◽  
Aligned Carbon Nanotubes ◽  
Wide Range ◽  
Potential Applications ◽  
Vertically Aligned ◽  
Functionalization Of Carbon Nanotubes ◽  
Chemical Groups

This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs). The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers) to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

Scanning Tunneling Microscopy and Spectroscopy Studies of Single Wall Carbon Nanotubes

1998 ◽  
Vol 13 (9) ◽  
pp. 2380-2388 ◽  
Author(s):  
Teri Wang Odom ◽  
Jin-Lin Huang ◽  
Philip Kim ◽  
Min Ouyang ◽  
Charles M. Lieber
Keyword(s):  
Carbon Nanotubes ◽  
Scanning Tunneling Microscopy ◽  
Single Wall Carbon Nanotubes ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Metallic Behavior ◽  
Single Wall Carbon ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Spectroscopy Studies

Scanning tunneling microscopy and spectroscopy have been used to characterize the atomic structure and tunneling density of states of individual single wall carbon nanotubes (SWNT's) and ropes containing many SWNT's. Analysis of atomically resolved SWNT images shows that the nanotubes consist of a wide range of diameters and helicities with no one structure clearly dominant. Tunneling spectroscopy measurements made simultaneously on atomically resolved SWNT's exhibit semiconducting and metallic behavior that depend predictably on helicity and diameter. In addition the band gaps of the semiconducting tubes were also found to depend inversely on diameter. These results are compared to theoretical predictions, and the implications of these studies as well as important future directions are discussed.

Alignment and Deposition of Single Wall Carbon Nanotubes under the Influence of an Electric Field

2002 ◽  
Vol 761 ◽  
Author(s):  
Paul Jaynes ◽  
Thomas Tiano ◽  
Margaret Roylance ◽  
Charles Carey ◽  
Kenneth McElrath
Keyword(s):  
Carbon Nanotubes ◽  
Electric Field ◽  
Electronic Devices ◽  
Physical And Mechanical Properties ◽  
Single Wall Carbon Nanotubes ◽  
Enabling Technology ◽  
Single Wall Carbon ◽  
Nanoelectronic Devices ◽  
Wide Range ◽  
Field Lines

ABSTRACTSingle wall carbon nanotubes have aroused a great deal of interest because of their unique combination of electrical, physical and mechanical properties. However, the widespread use of SWNTs in composites and electronic devices is limited because of the difficulty of dispersing and processing these materials. This paper describes a method for depositing and aligning SWNTs from a dispersed solution onto a substrate under the influence of an electric field. Results indicate that SWNTs can be aligned in bulk in the direction of electric field lines, and that individual SWNT ropes may be deposited between two electrodes. The extent and type of deposition depends upon the electrode geometry and processing time. Electrical alignment of SWNTs is an enabling technology allowing manipulation of nanomaterials using standard processing. It could eventually lead to a wide range of products, such as nanocomposites with aligned fillers and nanoelectronic devices.

Polarized Raman Spectroscopy on Isolated Single-Wall Carbon Nanotubes

2000 ◽  
Vol 85 (25) ◽  
pp. 5436-5439 ◽  
Author(s):  
G. S. Duesberg ◽  
I. Loa ◽  
M. Burghard ◽  
K. Syassen ◽  
S. Roth
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Polarized Raman Spectroscopy ◽  
Polarized Raman

Carbon Nanotube-Based Stretchable Hybrid Material Film for Electronic Devices and Applications

2020 ◽  
Vol 20 (7) ◽  
pp. 4549-4556
Author(s):  
Laura Fazi ◽  
Daniele Mirabile Gattia ◽  
Luigi Pavone ◽  
Anna Prioriello ◽  
Valerio Scacco ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electronic Devices ◽  
Electrical Characterization ◽  
Technological Application ◽  
Single Wall Carbon Nanotubes ◽  
Inert Material ◽  
Wide Range ◽  
Strong Adhesion ◽  
Simple Technology

To meet the increasing demand, for stretchable conductive materials in a wide range of applications, innovative conductors based on single wall carbon nanotubes (SWCNT) self-grafted on different polymer films, are assembled. Aiming at a simple technology for flexible and stretchable electronic devices, and contrary to what commonly reported for carbon nanotubes (CNT), no chemical functionalization of SWCNT is necessary for stable grafting onto several polymeric surfaces. The novelty and functionality of our composite materials stand in the synergy among the intrinsic biocompatibility of CNT, a fully inert material, their electrical conductivity, and the stretchable-viscoelastic properties of the polymer-nanotube bundles composites. Electrical characterization of both unstretched and strongly stretched planar film conductors is provided, demonstrating the use of this new composite material for technological application. Also, an insight into the mechanisms of strong adhesion to the polymer is obtained by scanning electron microscopy (SEM) of the surface composite. As an example of technological application of such stretchable circuitry, the electrical functionality of a carbon nanotube-based six-sensor (electrode) grid is used to record subdural electrocorticograms in freely-moving laboratory rats over approximately three months.

scholarly journals Dispersion of single-wall carbon nanotubes with supramolecular Congo red – properties of the complexes and mechanism of the interaction

2017 ◽  
Vol 8 ◽  
pp. 636-648 ◽  
Author(s):  
Anna Jagusiak ◽  
Barbara Piekarska ◽  
Tomasz Pańczyk ◽  
Małgorzata Jemioła-Rzemińska ◽  
Elżbieta Bielańska ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Targeted Delivery ◽  
Congo Red ◽  
Binding Capacity ◽  
Aqueous Media ◽  
Strong Interactions ◽  
Single Wall Carbon Nanotubes ◽  
Scanning Calorimetry ◽  
Single Wall Carbon ◽  
Wide Range

A method of dispersion of single-wall carbon nanotubes (SWNTs) in aqueous media using Congo red (CR) is proposed. Nanotubes covered with CR constitute the high capacity system that provides the possibility of binding and targeted delivery of different drugs, which can intercalate into the supramolecular, ribbon-like CR structure. The study revealed the presence of strong interactions between CR and the surface of SWNTs. The aim of the study was to explain the mechanism of this interaction. The interaction of CR and carbon nanotubes was studied using spectral analysis of the SWNT–CR complex, dynamic light scattering (DLS), differential scanning calorimetry (DSC) and microscopic methods: atomic force microscopy (AFM), transmission (TEM), scanning (SEM) and optical microscopy. The results indicate that the binding of supramolecular CR structures to the surface of the nanotubes is based on the "face to face stacking". CR molecules attached directly to the surface of the nanotubes can bind further, parallel-oriented molecules and form supramolecular and protruding structures. This explains the high CR binding capacity of carbon nanotubes. The presented system – containing SWNTs covered with CR – offers a wide range of biomedical applications.

Electron Transport in Deformed Carbon Nanotubes

2004 ◽  
Vol 126 (3) ◽  
pp. 222-229 ◽  
Author(s):  
H. T. Johnson ◽  
B. Liu ◽  
Y. Y. Huang
Keyword(s):  
Carbon Nanotubes ◽  
Electron Transport ◽  
Electrical Properties ◽  
Unit Length ◽  
Homogeneous Deformation ◽  
Single Wall Carbon Nanotubes ◽  
Strain Effect ◽  
Material System ◽  
Modeling Methods ◽  
Wide Range

Carbon nanotubes are a material system of increasing technological importance with superb mechanical and electrical properties. It is well known that depending on details of atomic structure, nanotubes may be electrically conducting, semiconducting, or insulating, so deformation is believed to have strong effects on nanotube electrical properties. In this paper, a combination of continuum, empirical atomistic, and quantum atomistic modeling methods are used to demonstrate the effect of homogeneous deformation—tension, compression, and torsion—on the electrical conductance and current versus voltage (I(V)) characteristics of a variety of single wall carbon nanotubes. The modeling methods are used in a coupled and efficient multiscale formulation that allows for computationally inexpensive analysis of a wide range of deformed nanotube configurations. Several important observations on the connection between mechanical and electrical behavior are made based on the transport calculations. First, based on the I(V) characteristics, electron transport in the nanotubes is evidently fairly insensitive to homogeneous deformation, though in some cases there is a moderate strain effect at either relatively low or high applied voltages. In particular, the conductance, or dI/dV behavior, shows interesting features for nanotubes deformed in torsion over small ranges of applied bias. Second, based on a survey of a range of nanotube geometries, the primary determining feature of the I(V) characteristics is simply the number of conduction electrons available per unit length of nanotube. In other words, when the current is normalized by the number of free electrons on the tube cross section per unit length, which itself is affected by extensional (but not torsional) strain, the I(V) curves of all single walled carbon nanotubes are nearly co-linear.

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