Percolation in Multi-Wall Carbon Nanotube-Epoxy Composites Influence of processing parameters, nanotube aspect ratio and electric fields on the bulk conductivity

2003 ◽  
Vol 788 ◽  
Author(s):  
Jan K.W. Sandler ◽  
Alan H. Windle ◽  
Christian A. Martin ◽  
Matthias-Klaus Schwarz ◽  
Wolfgang Bauhofer ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Aspect Ratio ◽  
Electric Fields ◽  
Processing Parameters ◽  
Bulk Conductivity ◽  
Multi Wall Carbon Nanotubes ◽  
Electrical Percolation ◽  
Mechanical Stirring ◽  
Multi Wall Carbon Nanotube

ABSTRACTA simple mechanical stirring process leads to charge-stabilised dispersions of aligned, substrate-grown, CVD-grown multi-wall carbon nanotubes in an epoxy resin. Subsequent sample processing, after the addition of the hardener, can be used to induce the nanotube agglomeration necessary to achieve electrically conductive bulk composites at low loading fractions. Both the nanotube percolation threshold and the resulting bulk conductivity can be adjusted by selection of suitable processing parameters and nanotube aspect ratio. This behaviour of aligned CVD-grown multi-wall carbon nanotubes allows lower electrical percolation thresholds than are possible with entangled multi-wall carbon nanotubes, single-wall carbon nanotube bundles, or carbon black in an epoxy matrix. Furthermore, the application of electric fields during composite processing induces the formation of aligned multi-wall carbon nanotube networks between electrodes dipped into the dispersion. Such composites show an electrical conductivity above the anti-static level and retain a degree of optical transmissivity.

Experimental investigation and modelling of drilling on multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposites

2016 ◽  
Vol 232 (11) ◽  
pp. 1943-1959 ◽  
Author(s):  
Kalyan Kumar Singh ◽  
Dhiraj Kumar
Keyword(s):  
Carbon Nanotubes ◽  
Surface Roughness ◽  
Carbon Nanotube ◽  
Feed Rate ◽  
Spindle Speed ◽  
Glass Fabric ◽  
Multi Wall Carbon Nanotubes ◽  
Weight Percentage ◽  
Drill Diameter ◽  
Multi Wall Carbon Nanotube

The primary objective of this research is to investigate the effect of multi-wall carbon nanotubes on drilling of multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposites. The experiments were conducted on composites with varying the weight percentage of multi-wall carbon nanotubes content to analyse drilling-induced delamination and surface roughness, which affect the quality and property of the drilled holes. The drilling parameters considered are spindle speed, feed rate and drill diameter. The microstructure of the holes was characterized using field emission scanning electron microscopy methods. For correlating the effect of the weight percentage of carbon nanotubes with the referred drilling parameters, a mathematical model was used, based on response surface methodology. For development of the mathematical model, four factors, namely, spindle speed, feed rate, diameter of drill and weight percentage of carbon nanotubes, were taken into account. The result established that delamination and surface roughness are reduced as multi-wall carbon nanotubes’ content increases. Maximum improvement in delamination factor was observed in the case of 1.0 wt% multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposite, which is 25% and 31.09% at the entrance and exit sides of the hole, respectively. With an increase in the feed rate and the drill diameter, delamination factor increases; however, with an increase in spindle speed, delamination factor decreases. Lower value of surface roughness (1.113 µm) was observed in 1.5 wt% of multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposite. However, surface roughness increases with an increase in feed rate and drill diameter.

Enhanced figure of merit in Mg2Si0.877Ge0.1Bi0.023/multi wall carbon nanotube nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65328-65336 ◽  
Author(s):  
Nader Farahi ◽  
Sagar Prabhudev ◽  
Matthieu Bugnet ◽  
Gianluigi A. Botton ◽  
Jianbao Zhao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Power Factor ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
Multi Wall Carbon Nanotubes ◽  
Energy Filtering ◽  
Multi Wall Carbon Nanotube

Adding multi wall carbon nanotubes to Mg2Si0.877Ge0.1Bi0.023 led to an increased power factor via energy filtering as well as a lowered thermal conductivity via increased phonon scattering, and thus an enhanced thermoelectric performance.

scholarly journals Comparing the performance of electrospun and cast nanocomposite film of polyamide-6 reinforced with multi-wall carbon nanotubes

2018 ◽  
Vol 35 (1) ◽  
pp. 45-64 ◽  
Author(s):  
N Ghane ◽  
S Mazinani ◽  
AA Gharehaghaji
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Polyamide 6 ◽  
Nanocomposite Films ◽  
Multi Wall Carbon Nanotubes ◽  
Nanofiber Diameter ◽  
Polymeric Emulsifier ◽  
Reported Data ◽  
Multi Wall Carbon Nanotube

This study aims at fabrication and characterization of two different structures of electrically conductive polyamide 6/multi-wall carbon nanotube nanocomposite films at different multi-wall carbon nanotube concentrations including electrospun nanofibrous and cast films. Morphology, embedded multi-wall carbon nanotubes into nanofiber, thermal behavior, electrical conductivity and wettability of films were characterized. Scanning electron microscopy images depicted that the nanofiber diameter decreased with increased nanofillers. Enhancement of crystallinity, electrical and tensile properties, and simultaneously achieving a low percolation threshold confirmed good nanotube dispersion by employing a polymeric emulsifier, polyvinylpyrrolidone. The electrospun film crystalline content increased 18.5% and the cast ones increased 46.8% at 7 wt.% multi-wall carbon nanotubes loading. The electrospun and cast membrane electrical conductivity increased by 10 and 12 orders of magnitude. These results demonstrated higher values compared to previously reported data for polyamide 6/multi-wall carbon nanotube nanocomposites. The electrospun film Young’s modulus increased 93% and that of casted one increased 267%, due to the increased crystallinity after adding carbon nanotubes into the films.

Online solid sampling platform using multi-wall carbon nanotube assisted matrix solid phase dispersion for mercury speciation in fish by HPLC-ICP-MS

2015 ◽  
Vol 30 (4) ◽  
pp. 882-887 ◽  
Author(s):  
Dongyan Deng ◽  
Shu Zhang ◽  
He Chen ◽  
Lu Yang ◽  
Hui Yin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Solid Phase ◽  
Mercury Speciation ◽  
Solid Sampling ◽  
Multi Wall Carbon Nanotubes ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Icp Ms ◽  
Multi Wall Carbon Nanotube

A method using multi-wall carbon nanotubes assisted matrix solid phase dispersion was developed to couple with HPLC-ICP-MS for mercury speciation.

scholarly journals Analyzing Effects of Multi-Wall Carbon Nanotubes (MWCNT) & Polyethylene Glycol (PEG) on Performance of Water Base Mud (WBM) in Shale Formation

2018 ◽  
Vol 11 (1) ◽  
pp. 29-47
Author(s):  
Koorosh Tookalloo ◽  
Javad Heidarian ◽  
Mohammad Soleymani ◽  
Alimorad Rashidi ◽  
Mahdi Nazarisaram
Keyword(s):  
Carbon Nanotubes ◽  
Polyethylene Glycol ◽  
Carbon Nanotube ◽  
Rheological Properties ◽  
Multi Wall Carbon Nanotubes ◽  
Local Water ◽  
Shale Recovery ◽  
Water Base ◽  
Stability Of Water ◽  
Multi Wall Carbon Nanotube

Background: Due to importance and unique properties of Multi-Wall Carbon Nanotube(s) (MWCNT), in the present study, effectiveness of these materials in Water Base Mud (WBM) is evaluated. Objective: The impacts of mud additives, local water and the addition of phases of bentonite and surfactants on the rheological properties, water loss and stability of water base mud in the absence of Multi-Wall Carbon Nanotube have been experimentally investigated. Materials and Methods: Then, the same experiment performed in the presence of Multi-Wall Carbon Nanotube to determine the efficiency and impact of Nanoparticles (NPs) on the properties of water base mud. The results have shown that additives, local water, Multi-Wall Carbon Nanotube dimensions, addition phase of bentonite and surfactants have influenced the rheological properties of the water base mud. Results: When Multi-Wall Carbon Nanotubes and polyethylene glycol alone or together are added, the performance terms of rheological properties decrease as by the subsequent order CNT; CNT + PEG; PEG. Multi-Wall Carbon Nanotube improves shale integrity and increases shale recovery. Conclusion: In general, the presence of Multi-Wall Carbon Nanotube increases the efficiency of polymers and rheological properties of the water base mud and eventually the shale stability is achieved.

The Attachment of Carbon Nanotube on a Blunt AFM Tip Using Electric Fields

2004 ◽  
Author(s):  
Hyung Woo Lee ◽  
Soon Geun Kwon ◽  
Soo Hyun Kim ◽  
Yoon Keun Kwak ◽  
Chang Soo Han
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Electric Fields ◽  
Low Cost ◽  
Reliable Technique ◽  
Force Microscopy ◽  
Atomic Force

We report a simple, low cost, reliable technique of making carbon nanotube (CNT) modified atomic force microscopy (AFM) tip. We used the dielectrophoresis and the electrophoresis to align and deposit carbon nanotubes on the end of the AFM tip. From the simulation and the various experiments, we obtained the optimal electric condition, 0.32Vpp/μm. Also, we found that the blunt shape of the tip’s apex is more effective than sharpened one. Through the experiments, we verified that the blunt shape is more effective over 50% than the sharpened one in the attachment of CNTs. By comparing the scanning results between the CNT modified tip and a normal AFM tip, we obtained the improvement in efficiency of 23%.

Highly Organized Carbon Nanotube-PDMS Hybrid System for Multifunctional Flexible Devices

2007 ◽  
Author(s):  
Yung J. Jung ◽  
Laila Jaber-Ansari ◽  
Xugang Xiong ◽  
Sinan Mu¨ftu¨ ◽  
Ahmed Busnaina ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electric Fields ◽  
Composite Structures ◽  
Field Enhancement ◽  
Chemical Vapor ◽  
Casting Process ◽  
Dip Coating ◽  
Network Architectures ◽  
Multiwalled Carbon

We will present a method to fabricate a new class of hybrid composite structures based on highly organized multiwalled carbon nanotube (MWNT) and singlewalled carbon nanotube (SWNT) network architectures and a polydimethylsiloxane (PDMS) matrix for the prototype high performance flexible systems which could be used for many daily-use applications. To build 1–3 dimensional highly organized network architectures with carbon nanotubes (both MWNT and SWNT) in macro/micro/nanoscale we used various nanotube assembly processes such as selective growth of carbon nanotubes using chemical vapor deposition (CVD) and self-assembly of nanotubes on the patterned trenches through solution evaporation with dip coating. Then these vertically or horizontally aligned and assembled nanotube architectures and networks are transferred in PDMS matrix using casting process thereby creating highly organized carbon nanotube based flexible composite structures. The PDMS matrix undergoes excellent conformal filling within the dense nanotube network, giving rise to extremely flexible conducting structures with unique electromechanical properties. We will demonstrate its robustness under large stress conditions, under which the composite is found to retain its conducting nature. We will also demonstrate that these structures can be directly utilized as flexible field-emission devices. Our devices show some of the best field enhancement factors and turn-on electric fields reported so far.

Ultrasound promoted green oxidation of alkenes with hydrogen peroxide in the presence of iron porphyrins supported on multi-walled carbon nanotubes

2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Heterogeneous Catalyst ◽  
Multi Wall Carbon Nanotubes ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

In the present work, oxidation of alkenes with hydrogen peroxide in the presence of meso-tetrakis(4-hydroxyphenyl)porphyrinatoiron(III) chloride supported onto surface of functionalized multi-wall carbon nanotubes (FMWCNT), [ Fe ( THPP ) Cl@MWCNT ], is reported. The simple heterogeneous catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and also thermal analysis. The amount of the catalyst loaded on the nanotubes was determined by atomic absorption spectroscopy. This heterogeneous catalyst proved to be an efficient and green catalyst and was successfully able to activate hydrogen peroxide without any additive toward the oxidation of alkenes in ethanol as a green solvent. Performance of the catalyst in oxidation of various alkenes was inspected under reflux, ultrasonic irradiation and mechanical stirring. Moreover, the catalyst can be reused several times under similar conditions.

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