scholarly journals Resonance Raman and IR spectroscopy of aligned carbon nanotube arrays with extremely narrow diameters prepared with molecular catalysts on steel substrates

2017 ◽  
Vol 19 (45) ◽  
pp. 30667-30674 ◽  
Author(s):  
Sagar Motilal Jain ◽  
Federico Cesano ◽  
Domenica Scarano ◽  
Tomas Edvinsson
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Ir Spectroscopy ◽  
Resonance Raman ◽  
Nanotube Arrays ◽  
Molecular Catalyst ◽  
Carbon Nanotube Arrays ◽  
Molecular Catalysts ◽  
Steel Substrates ◽  
Raman And Ir Spectroscopy

Resonance and IR spectroscopy of carbon nanotubes with extremely narrow diameters grown directly on steel grids using a molecular catalyst.

scholarly journals The shape of the orientation distribution of carbon nanotubes in aligned arrays

2014 ◽  
Vol 70 (a1) ◽  
pp. C596-C596
Author(s):  
Ulla Vainio ◽  
Thea Schnoor ◽  
Sarathlal Koyiloth Vayalil ◽  
Karl Schulte ◽  
Martin Müller ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Iron Catalyst ◽  
Chemical Vapour ◽  
Orientation Distribution ◽  
Steric Interaction ◽  
Nanotube Arrays ◽  
X Ray ◽  
Carbon Nanotube Arrays ◽  
Vertically Aligned

Recent simulations of vertically aligned carbon nanotube arrays have shown that the shape of the orientation distribution of nanotubes within the array has a drastic effect on the electrical properties of the array. Orienting of shape-anisotropic objects can be carried out in several different ways such as shearing, magnetically steering, or by vibrating the objects. Nevertheless, perfect orientation is difficult if not impossible to achieve. In the case of the growth of carbon nanotube arrays, self-confinement can occur affecting the resultant orientation distribution. Yet so far the shape of the orientation distribution has not been quantified in great detail and it has been mostly assumed to be Gaussian or Lorentzian. In the present work, multi-walled carbon nanotube arrays were grown via aerosol-assisted chemical vapour deposition with iron catalyst and investigated using small-angle X-ray scattering, a method perfectly suited to characterizing the orientation of carbon nanotubes. Using a microfocused X-ray beam of 24 μm x 17 μm in size at beamline P03 of the PETRA III synchrotron storage ring in Hamburg, we determined the orientation distribution of the vertically aligned carbon nanotubes along the film height. Remarkably, the packing density of the carbon nanotubes seems to correlate not only with the width of the distribution but also its shape. The shape of the orientation distribution was then compared to that from different oriented systems. These findings indicate that by using alignment methods that are based on steric interaction between particles, such as shearing or self-confinement during particle growth, the system will reach an alignment with an orientation distribution closer to the Laplace distribution than to the normal distribution. Such a finding has profound implications for simulation studies of mechanical, electrical and other properties of many hierarchical materials.

Analysis of Visible Radiative Properties of Vertically Aligned Multi-Walled Carbon Nanotubes

2010 ◽  
Author(s):  
Hua Bao ◽  
Xiulin Ruan ◽  
Timothy S. Fisher
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Volume Fraction ◽  
Incidence Angle ◽  
Radiative Properties ◽  
Tube Length ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Finite-difference time-domain method is used to investigate the optical properties of vertical arrays of multi-walled carbon nanotubes. Individual carbon nanotubes are treated as solid circular cylinders with an effective dielectric tensor. Our results confirm that carbon nanotube arrays have extremely low reflectivity as observed in experiments. Compared with the commonly used Maxwell-Garnett theory, our calculations generally give larger reflectance and absorptance and smaller transmittance, which are attributed to the diffraction and scattering within the cylinder array structure. The effects of volume fraction, tube length, and incidence angle on radiative properties are investigated respectively. Low volume fraction and long tubes are more favorable to achieve low reflectance and high absorptance. The angular dependence study shows that there exists an optimum incidence angle at which the reflectance can be minimized, indicating that a small misalignment in carbon nanotube arrays can slightly enhance the absorptance. Our results also indicate that an even darker material could be achieved by using carbon nanotubes with good alignment on the top surface.

Selective sorting of metallic/semiconducting single-walled carbon nanotube arrays by ‘igniter-assisted gas-phase etching’

2018 ◽  
Vol 2 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Qiuchen Zhao ◽  
Zequn Wang ◽  
Lianming Tong ◽  
Zhe Zheng ◽  
Wenping Hu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Small Molecules ◽  
Gas Phase ◽  
Single Walled Carbon Nanotubes ◽  
Nanotube Arrays ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Carbon Nanotube Arrays ◽  
Walled Carbon Nanotubes

Small molecules are used as “igniters” for the selective sorting of metallic/semiconducting single-walled carbon nanotubes by a gas phasing etching process.

Effects of Carbon Nanotube Structure on Protein Adsorption

2005 ◽  
Author(s):  
Sungwon S. Kim ◽  
Tom T. Huang ◽  
Timothy S. Fisher ◽  
Michael R. Ladisch
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Protein Adsorption ◽  
Hydrophobic Interactions ◽  
High Surface ◽  
Blocking Agent ◽  
Growth Conditions ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Biosensor Applications

Outstanding transport characteristics and high surface-to-volume ratios are several advantages that carbon nanotubes possess that make them attractive candidates for protein immobilization matrices in biosensor applications. A further advantage of using carbon nanotubes is that their structure (e.g., diameter, length, density) can potentially be controlled during synthesis. In the present study, the effects of carbon nanotube structure on enzyme immobilization onto carbon nanotube arrays are investigated. Bovine serum albumin (BSA) serves as both a blocking agent for prevention of nonspecific adsorption and as a support for anchoring bioreceptors. BSA, a globular protein having a 4 to 6 nm characteristic dimension, is stably adsorbed through mechanisms that involve hydrophobic interactions between surfaces presented by the carbon nanotubes and the spacing between the nanotubes with the protein. Protein adsorption is confirmed by fluorescence microscopy of surfaces that have been exposed to fluourescein isothiocyanate (FITC) labeled BSA. The adsorption of biotinylated BSA can be used, through a sandwich immobilization scheme, to provide an anchor for streptavidin, which in turn has at least one other adsorption site that is specific for other biotinylated proteins such as glucose oxidase that would form a biorecognition or catalytic element in a functional biosensor. Correlation between carbon nanotube structure and protein adsorption at the nano-bio interface could eventually lead to growth conditions that yield carbon nanotubes for biosensor applications with optimal protein adsorption characteristics.

Fluffy carbon nanotubes produced by shearing vertically aligned carbon nanotube arrays

Carbon ◽  
2009 ◽  
Vol 47 (2) ◽  
pp. 538-541 ◽  
Author(s):  
Qiang Zhang ◽  
Guang-Hui Xu ◽  
Jia-Qi Huang ◽  
Wei-Ping Zhou ◽  
Meng-Qiang Zhao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Vertically Aligned

scholarly journals Characterization of contact resistances in ceramic-coated vertically aligned carbon nanotube arrays

RSC Advances ◽  
2019 ◽  
Vol 9 (13) ◽  
pp. 7266-7275
Author(s):  
Meng Li ◽  
Ning Yang ◽  
Vanessa Wood ◽  
Hyung Gyu Park
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nanotube Arrays ◽  
Aligned Arrays ◽  
Carbon Nanotube Arrays ◽  
Vertically Aligned

End- and side-contact resistances between carbon nanotubes and contacts are easily probed in vertically aligned arrays.

The Internal Buckling Behavior Induced by Growth Self-restriction in Vertical Multi-walled Carbon Nanotube Arrays

MRS Advances ◽  
2018 ◽  
Vol 3 (45-46) ◽  
pp. 2815-2823 ◽  
Author(s):  
Quan Zhang ◽  
Guo-an Cheng ◽  
Rui-ting Zheng
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Van Der Waals ◽  
Nanotube Arrays ◽  
Nanotube Array ◽  
Static Compression ◽  
Carbon Nanotube Array ◽  
Carbon Nanotube Arrays ◽  
Compression Model ◽  
Quasi Static Compression

ABSTRACTThe internal buckling is a common phenomenon in the as-grown carbon nanotube arrays. It makes the physical properties of carbon nanotube array in experiment lower than that in theory. In this work, we analyzed the formation and evolution mechanism of the internal buckling based on quasi-static compression model, which is different from collective effect of the van der Waals interactions. The self-restriction effect and the different growth rate of carbon nanotubes verify the possibility of the quasi-static compression model to explain the morphology evolution of vertical carbon nanotube arrays, especially the phenomenon of the quasi-straight and bent carbon nanotubes coexisted in the array. We generalized the Euler beam to wave-like beam and explained the mechanism of high-mode buckling combined with the van der Waals interaction. The calculated result about the link between compressive stress and strain confirms with the stage of collective buckling in the quasi-static compression test of carbon nanotube array. Preparation of well-organized carbon nanotube arrays was strong evidence verified the effect of self-restriction in experiment.

scholarly journals Permeation of Water Nanodroplets on Carbon Nanotubes Forests

MRS Advances ◽  
2017 ◽  
Vol 2 (02) ◽  
pp. 123-128
Author(s):  
Ygor M. Jaques ◽  
Douglas S. Galvao
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulations ◽  
Pore Size ◽  
Water Droplet ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Tube Arrays ◽  
Dynamics Simulations

ABSTRACT Fully atomistic molecular dynamics simulations were carried out to investigate how a liquid-like water droplet behaves when into contact with a nanopore formed by carbon nanotube arrays. We have considered different tube arrays, varying the spacing between them, as well as, different chemical functionalizations on the uncapped nanotubes. Our results show that simple functionalizations (for instance, hydrogen ones) allow tuning up the wetting surface properties increasing the permeation of liquid inside the nanopore. For functionalizations that increase the surface hydrophilicity, even when the pore size is significantly increased the droplet remains at the surface without tube permeation.

Sign in / Sign up

Export Citation Format

Share Document