Influence of graphene–carbon nanotubes and processing parameters on electrical and dielectric properties of polypropylene nanocomposites

2021 ◽  
pp. 002199832110067
Author(s):  
UO Uyor ◽  
API Popoola ◽  
OM Popoola ◽  
VS Aigbodion
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Graphene Nanosheets ◽  
Processing Parameters ◽  
Melt Processing ◽  
Future Research ◽  
Relative Dielectric Permittivity ◽  
Melt Compounding ◽  
Fabrication Parameters

In this study, the effect of carbon nanotubes (CNTs) and graphene nanosheets (GNs) on the microstructure, electrical conductivity and relative dielectric permittivity of polypropylene (PP) nanocomposites were investigated in relation to the melt compounding parameters. Although CNTs/GNs can significantly improve the conductivity and permittivity of PP nanocomposites, more significant results can be obtained by using optimal fabrication parameters. For optimal melt processing parameters using Taguchi optimization method, electrical conductivity and relative dielectric permittivity of about 3.08 × 10−5 S/m and 158.97 were achieved, whereas only about 1.34 × 10−11 S/m and 2.02 were measured for pure PP respectively. Therefore, this study showcased optimal melt compounding process parameters for the endless future research on PP-CNTs/GNs nanocomposites for various advanced engineering applications. This will also guide future research on the uniform use of melt fabrication parameters for proximity in comparison of results published on PP-CNTs/GNs nanocomposites.

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.

A Comparison of the Effect of Hydroxyl Modified Carbon Nanotubes and Graphenes on the Electrical and Mechanical Properties of Their Polyurethane Composites

2012 ◽  
Vol 622-623 ◽  
pp. 781-786
Author(s):  
Sarojini Swain ◽  
Subhendu Bhattacharya ◽  
Ram Avatar Sharma ◽  
Lokesh Chaudhari
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Filler Content ◽  
Graphene Nanosheets ◽  
Three Dimensional ◽  
Conduction System ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Conduction Mechanisms ◽  
Modified Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Hydroxyl modified multi-walled carbon nanotubes (OH-MWCNT)/ polyurethane (PU) and graphene nanosheets (GNS)/PU composites were prepared by dispersing the OH-MWCNT and GNS at different wt % in to the PU matrix. It was found that the electrical percolation threshold of the GNS/PU composite is much higher compared to that of OH-MWCNT/PU and also the electrical conductivity of the OH-MWCNT/PU composite is higher than the GNS/PU composite in the same level of filler content. This may be due to the two composites having different electrical conduction mechanisms: The OH-MWCNT/PU composite represents a three dimensional conduction system while, the GNS/PU composite represents a two dimensional conduction system. The improvement in the electrical conductivity with the incorporation of GNS as a filler in the composite is far lower than what theoretically expected. It is also observed that the tensile strength of the OH-MWCNT/PU composite is higher compared to the GNS/PU in the same level filler content.

Parameter optimization of aluminum alloy thin structures obtained by Selective Laser Melting

MRS Advances ◽  
2019 ◽  
Vol 4 (55-56) ◽  
pp. 2997-3005
Author(s):  
Malena Ley Bun Leal ◽  
Barbara Bermudez-Reyes ◽  
Patricia del Carmen Zambrano Robledo ◽  
Omar Lopez-Botello
Keyword(s):  
Selective Laser Melting ◽  
Process Parameters ◽  
Orthogonal Design ◽  
Processing Parameters ◽  
Future Research ◽  
Laser Melting ◽  
Complex Process ◽  
The Relationship ◽  
Fabrication Parameters

ABSTRACTSelective Laser Melting (SLM) involves numerous fabrication parameters, the interaction between those parameters determine the final characteristics of the resulting part and because of the latter, it is considered a complex process. Low-density components is one of the main issues of the SLM process, due to the incorrect selection of process parameters. These defects are undesired in high specialized applications (i.e. aerospace, aeronautic and medical industries). Therefore, the characterization of the defects (pores) found in aluminum parts manufacture by SLM and the relationship with fabrication parameters was performed. A robust orthogonal design of experiments was implemented to determine process parameters, and then parts were manufactured in SLM. Relative density of the samples was then characterized using the Archimedes principle and microscopy; the data was then statistically analyzed in order to determine the optimal process parameters. The main purpose of the present research was to establish the best processing parameters of an in-house SLM system, as well as to characterize the pore geometry in order to fully eliminate pores in a future research.

scholarly journals Rapid Prototyping of Efficient Electromagnetic Interference Shielding Polymer Composites via Fused Deposition Modeling

2018 ◽  
Vol 9 (1) ◽  
pp. 37 ◽  
Author(s):  
Luiz Ecco ◽  
Sithiprumnea Dul ◽  
Débora Schmitz ◽  
Guilherme Barra ◽  
Bluma Soares ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Electromagnetic Interference ◽  
Fused Deposition Modeling ◽  
Processing Parameters ◽  
Emi Shielding ◽  
Fused Deposition ◽  
Multi Walled Carbon Nanotubes ◽  
Deposition Modeling ◽  
Walled Carbon Nanotubes

Acrylonitrile–butadiene–styrene (ABS) filled with 6 wt.% of multi-walled carbon nanotubes and graphene nanoplatelets was extruded in filaments and additively manufactured via fused deposition modeling (FDM). The electrical conductivity and electromagnetic interference shielding efficiency (EMI SE) in the frequency range between 8.2 and 12.4 GHz of the resulting 3D samples were assessed. For comparison purposes, compression molded samples of the same composition were investigated. Electrical conductivity of about 10−4 S·cm−1 and attenuations of the incident EM wave near 99.9% were achieved for the 3D components loaded with multi-walled carbon nanotubes, almost similar to the correspondent compression molded samples. Transmission electron microscopy (TEM) images of ABS composite filaments show that graphene nanoplatelets were oriented along the polymer flow whereas multi-walled carbon nanotubes were randomly distributed after the extrusion process. The electrical conductivity and electromagnetic interference (EMI) shielding properties of compression molded and FDM manufactured samples were compared and discussed in terms of type of fillers and processing parameters adopted in the FDM process, such as building directions and printing patterns. In view of the experimental findings, the role of the FDM processing parameters were found to play a major role in the development of components with enhanced EMI shielding efficiency.

Optimization of the Electrical Conductivity of ABS Nanocomposites filled with Carbon Black and Carbon Nanotubes

2006 ◽  
Vol 977 ◽  
Author(s):  
Shantanu Talapatra ◽  
Rosario A. Gerhardt
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Black ◽  
Processing Parameters ◽  
Electrical Performance ◽  
Single Wall Carbon Nanotubes ◽  
Structural Applications ◽  
Filler Fraction ◽  
Using Data

AbstractPoly(acrylonitrile-co-butadiene-co-styrene) (ABS) is a thermoplastic polymer that is used in numerous structural applications as a result of its excellent mechanical properties. For those applications where good electrical conductivity is also desired, carbon black is often used as the filler of choice. Most reports in the literature indicate that at least 8 wt% carbon black filler is needed in order to achieve percolation. Our group recently reported that by manual mixing of ABS pellets and carbon black to create a segregated microstructure, percolation was achieved at an unprecedented low filler fraction of less than 0.01 wt% carbon black, a value which is comparable to or even better than that obtained using single wall carbon nanotubes as the filler. While the ABS/CB composites had excellent electrical performance, with a conductivity as high as 10-1 S/m, their mechanical strength was compromised.In this paper we report on new experiments designed to maintain high electrical conductivity while improving on the mechanical behavior of percolating ABS/CB nanocomposites. The experiments were aimed at controlling the processing parameters such as temperature, pressure and time during hot pressing of the mechanically mixed precursor materials. Using data obtained at the various temperature-pressure combinations used, it will be shown that similar volume percentages of carbon black and carbon nanotubes can be used to obtain equivalent conductivities, suitable for EMI shielding, while still maintaining good mechanical properties.

The Influence of Surface Modification of Multi-Walled Carbon Nanotubes on the Electrical Property of its Polyethylene Composites

2008 ◽  
Vol 47-50 ◽  
pp. 1145-1148 ◽  
Author(s):  
Na Xie ◽  
Qing Jie Jiao ◽  
Chong Guang Zang
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Mass Fraction ◽  
Good Method ◽  
Processing Technique ◽  
Melt Processing ◽  
Multi Walled Carbon Nanotubes ◽  
Ldpe Composites ◽  
Surface Modified ◽  
Walled Carbon Nanotubes

A good method for dispersing Multi-walled carbon nanotubes (MWNTs) in LDPE matrix by melt processing technique had been developed. The surface of MWNTs was modified by HNO3, then, treated with γ-aminopropyltriethoxy Silane. The surface-modified MWNTs homogeneous LDPE composites with 0-0.35 mass fraction MWNTs loading had been evaluated for electrical conductivity. The composites’ electrical conductivity (σDC) was improved for the good dispersion of MWNTs in LDPE matrix. The values of σDC obeyed a percolation power law with MWNTs concentration threshold 0.10 mass fraction. 10-2 s/cm conductivity for 0.15 mass fraction MWNTs loading indicated that the composites could be used as lightweight electrostatic shielding materials.

scholarly journals Electric/dielectric properties of composites filled with onion-like carbon and multiwalled carbon nanotubes

2015 ◽  
Vol 55 (2) ◽  
Author(s):  
Ieva Kranauskaitė ◽  
Jūras Banys ◽  
Ewa Talik ◽  
Vladimir Kuznetsov ◽  
Nicolas Nunn ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Dielectric Permittivity ◽  
Average Distance ◽  
Wide Frequency Range ◽  
Electric Properties ◽  
Multiwalled Carbon ◽  
Conductivity Increase ◽  
Polyurethane Composites ◽  
Properties Of Composites

The dielectric/electric properties of polyurethane composites filled with carbon nanotubes (CNTs), onion-like carbon (OLC) and mixed onion-like carbon/carbon nanotubes are compared across a wide frequency range from hertz to terahertz. The highest value of dielectric permittivity and electrical conductivity is observed in composites with carbon nanotubes. However, the dielectric/electric properties of composites filled with onion-like carbon are also very attractive and can be improved by addition of small amounts of carbon nanotubes due to the strong synergy effect. In composites with inclusions of mixed onion-like carbon/ carbon nanotubes, the dielectric permittivity and electrical conductivity increase due to the decreasing of both the potential barrier for carrier tunneling and the average distance between nanocarbon clusters.

Thermal conductivity from hierarchical heat sinks using carbon nanotubes and graphene nanosheets

Nanoscale ◽  
2015 ◽  
Vol 7 (44) ◽  
pp. 18663-18670 ◽  
Author(s):  
Chien-Te Hsieh ◽  
Cheng-En Lee ◽  
Yu-Fu Chen ◽  
Jeng-Kuei Chang ◽  
Hsi-sheng Teng
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Thermal Management ◽  
Graphene Nanosheets ◽  
Consumer Electronics ◽  
Experimental Results ◽  
Heat Sinks ◽  
Empirical Equations ◽  
The Relationship

The relationship between thermal conductivity (k) and electrical conductivity (ε) values was well described by two empirical equations. The experimental results were obtained within the 323–373 K range, suitably complementing the thermal management of chips for consumer electronics.

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