scholarly journals Segregated network polymer/carbon nanotubes composites

2004 ◽  
Vol 2 (2) ◽  
pp. 363-370 ◽  
Author(s):  
A. Mierczynska ◽  
J. Friedrich ◽  
H. Maneck ◽  
G. Boiteux ◽  
J. Jeszka
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Network Formation ◽  
Processing Parameters ◽  
Low Grade ◽  
Single Walled Carbon ◽  
Conductive Composites ◽  
Grade Material

AbstractIn this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.

scholarly journals 3D Monte Carlo simulation modeling for the electrical conductivity of carbon nanotube-incorporated polymer nanocomposite using resistance network formation

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Nanzhu Zhao 1 ◽  
Yongha Kim 1 ◽  
Joseph H. Koo 1
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Carbon Nanotube ◽  
Network Formation ◽  
Polymer Nanocomposite ◽  
Electrical Percolation ◽  
Resistance Network ◽  
3D Monte Carlo

High electrical and thermal conductivity associated with high stiffness and strength offer tremendous opportunities to the development of a series of carbon nanotube incorporated composite materials for a variety of applications. In particular, a small amount of carbon fibers or carbon nanotubes in a non-conductive polymer will transform a composite into a conductive material, which reveals superb potential of their future application in electronic devices. The relation between the amount of carbon nanotubes in a polymer and the electrical conductivity of it can be studied experimentally as well as theoretically with various simulation models. A three-dimensional (3D) Monte Carlo simulation model using resistance network formation was developed to study the relation between the electrical conductivity of the polymer nanocomposite and the amount of carbon nanotubes dispersed in it. In this model, carbon nanotubes were modeled as curvy cylindrical nanotubes with various lengths and fixed tube diameter, all of which were randomly distributed in a non-conductive constrained volume, which represents polymer. The model can be used to find the volumetric electrical resistance of a constrained cubic structure by forming a comprehensive resistance network among all of the nanotubes in contact. As more and more nanotubes were added into the volume, the electrical conductivity of the volume increases exponentially. However, once the amount of carbon nanotubes reached about 0.1 % vt (volume percentage), electrical percolation was detected, which was consistent with the experimental results. This model can be used to estimate the electrical conductivity of the composite matrix as well as to acquire the electrical percolation threshold.

Investigation of dielectric relaxation phenomena and AC electrical conductivity in graphite/carbon nanotubes/engine oil nanofluids

2020 ◽  
pp. 073168442095185
Author(s):  
S Barnoss ◽  
BMG Melo ◽  
M El Hasnaoui ◽  
MPF Graça ◽  
ME Achour ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Complex Impedance ◽  
Engine Oil ◽  
Positive Temperature ◽  
Multiwalled Carbon ◽  
Remarkable Change ◽  
Ac Electrical Conductivity

In this paper, we report an investigation on electrical conduction mechanisms of nanofluids based on commercial engine oil loaded with graphite (Gt) and multiwalled carbon nanotubes, at different concentrations. The impedance spectroscopy technique was used to measure the resistance and capacity characterizing each sample in a frequency range 100 Hz–1 MHz and a temperature range 300–400 K. Two formalisms were used to analyze the data: (a) the electrical conductivity which has found to follow the Jonscher’s law with single and double exponents for carbon nanotube concentrations below and above the percolation threshold, respectively, and (b) the complex impedance that has permitted to identify the relaxation peaks according to the Cole–Cole model. Both the two formalisms showed that when the carbon nanotube concentration is higher than the percolation threshold, a positive temperature coefficient and a remarkable change in conductivity were observed, suggesting that the presence of the carbon nanotube greatly affect the electrical properties of the engine oil as a result of additional polarization effect induced by these nanoparticles. Furthermore, the analysis of the temperature dependence of dc conductivity and relaxation time using the Arrhenius equation indicated the addition of carbon nanotubes into engine oil increase the activation energies.

Electrically conductive composites via infiltration of single-walled carbon nanotube-based aerogels

2010 ◽  
Vol 1258 ◽  
Author(s):  
Marcus A Worsley ◽  
Joshua D. Kuntz ◽  
Sergei Kucheyev ◽  
Alex V Hamza ◽  
Joe H Satcher ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Low Density ◽  
Electrically Conductive ◽  
Single Walled Carbon Nanotube ◽  
Insulating Materials ◽  
Conductive Composites ◽  
Electrical Conductivities

AbstractMany challenges remain in the effort to realize the exceptional properties of carbon nanotubes (CNT) in composite materials. Here, we report on electrically conductive composites fabricated via infiltration of CNT-based aerogels. The ultra low-density, high conductivity, and extraordinary robustness of the CNT aerogels make them ideal scaffolds around which to create conductive composites. Infiltrating the aerogels with various insulating materials (e.g. epoxy and silica) resulted in composites with electrical conductivities over 1 Scm-1 with as little as 1 vol% nanotube content. The electrical conductivity observed in the composites was remarkably close to that of the CNT scaffold in all cases.

Hexahapto-lanthanide interconnects between the conjugated surfaces of single-walled carbon nanotubes

2014 ◽  
Vol 43 (20) ◽  
pp. 7379-7382 ◽  
Author(s):  
Matthew L. Moser ◽  
Xiaojuan Tian ◽  
Aron Pekker ◽  
Santanu Sarkar ◽  
Elena Bekyarova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Lanthanide Metals ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanotube Networks

Organometallic bonding of lanthanide metals to the graphene sidewalls in single-walled carbon nanotube networks enhances the electrical conductivity, particularly in the case of Sm and Eu.

Effect of boron doping on the electrical conductivity of metallicity-separated single walled carbon nanotubes

Nanoscale ◽  
2018 ◽  
Vol 10 (26) ◽  
pp. 12723-12733 ◽  
Author(s):  
Kazunori Fujisawa ◽  
Takuya Hayashi ◽  
Morinobu Endo ◽  
Mauricio Terrones ◽  
Jin Hee Kim ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Boron Doping ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

We explored the effect of substitutional boron doping on the electrical conductivity of a metallicity-separated single walled carbon nanotube (SWCNT) assembly.

Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing

2021 ◽  
pp. 096739112110012
Author(s):  
Qingsen Gao ◽  
Jingguang Liu ◽  
Xianhu Liu
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Rheological Properties ◽  
Network Formation ◽  
Loss Modulus ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

Lipase on carbon nanotube - An active, selective, stable and easy to optimize nanobiocatalyst for kinetic resolutions

2021 ◽  
Author(s):  
Cristian Andrei Gal ◽  
Laura Edit Barabas ◽  
Judith Hajnal Bartha-Vari ◽  
Madalina Elena Moisa ◽  
Diana Balogh-Weiser ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Covalent Binding ◽  
Single Walled Carbon Nanotubes ◽  
Candida Antarctica ◽  
Flow Mode ◽  
Lipase B ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Kinetic Resolutions

An efficient nanobioconjugate of lipase B from Candida antarctica was prepared by the covalent binding on carboxy-functionalized single-walled carbon nanotubes and tested in batch and flow mode for the enzymatic...

scholarly journals Switching the optical and electrical properties of carbon nanotube hybrid films using a photoresponsive dispersant as a dopant

RSC Advances ◽  
2018 ◽  
Vol 8 (20) ◽  
pp. 11186-11190 ◽  
Author(s):  
H. Jintoku ◽  
Y. Matsuzawa ◽  
M. Yoshida
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electrical Properties ◽  
Single Walled Carbon Nanotubes ◽  
Optical And Electrical Properties ◽  
Hybrid Films ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

The light-induced switching of the optical and electrical properties of single-walled carbon nanotubes hybrid films with photoresponsive dispersant.

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