scholarly journals Mechanical, Thermal and Electromagnetic Shielding Effectiveness of MWCN-ABS Films

2021 ◽  
Author(s):  
R. B. Jagadeesh Chandra ◽  
B. Shivamurthy ◽  
M. Sathish Kumar ◽  
B. H. S. Thimmappa
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Tensile Strength ◽  
Petri Dish ◽  
Nanocomposite Films ◽  
Heating Process ◽  
Shielding Effectiveness ◽  
X Band ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractThe multi-walled carbon nanotubes (MWCNTs) and the poly(acrylonitrile-co-butadiene-co-styrene) (ABS) granulates are dispersed in acetone separately using a magnetic stirrer followed by ultrasonication. Further, both the solutions were mixed with magnetic stirring followed by ultrasonication. Neat-ABS film, 0.25 wt%, 0.5 wt% and 1 wt% of MWCNT-ABS nanocomposite films of the average thickness of 140 µm are fabricated by the solution molding using a petri dish, followed by room temperature curing and further hot compression to maintain uniform thickness. The tensile properties, thermal stability, electrical conductivity, and EMSE of all films are investigated. The results indicate that the addition of MWCNTs to ABS enhanced the mechanical properties and electrical conductivity, thermal stability, and EMSE. The 0.25 wt% MWCNT-ABS nanocomposite films show attractive mechanical, electrical, thermal, and EMSE as compared to neat-ABS films. More than 0.25 wt% MWCNTs in the ABS matrix deteriorates the tensile strength. However, 0.5 wt% MWCNT-ABS nanocomposites exhibit better tensile strength, Young’s modulus, electrical conductivity, and EMSE than neat-ABS. In this research, we used a low quantity of MWCNTs and followed a one-time heating process in the entire fabrication, and produced MWCNT-ABS nanocomposite films with reasonable properties. Hence, this may be one of the options to produce nanocomposites suitable for EMS materials. We recommend that these films may be used as interlayers to develop an X-band range electromagnetic wave shielding material.

scholarly journals Structure and electrical conductivity of polyvinyl alcohol films with multi-walled carbon nanotubes, cured in a magnetic field

2021 ◽  
Vol 13 (4) ◽  
pp. 457-464
Author(s):  
Sergey V. Vasin ◽  
◽  
Azat M. Nizametdinov ◽  
Viacheslav A. Sergeev ◽  
Michael S. Efimov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Polyvinyl Alcohol ◽  
Nanocomposite Films ◽  
Polymerization Process ◽  
Degree Of Orientation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Control Samples

The results of the study of the effect of the permanent magnetic field of a neodymium magnet on the polymerization process and the electrophysical characteristics of polyvinyl alcohol (PVA) films with the inclusion of multi-walled carbon nanotubes (MWCNTs) are presented. When studying the morphology of films using a scanning electron microscope, it was found that nanocomposite films with a thickness of 30 microns, cured in the presence of a magnetic field with the direction of the magnetic induction vector perpendicular to the surface of the films, have a homogeneous structure, while a significant number of MWCNTs agglomerations are observed in control samples of films. Measurements of the conductivity of films in the direction of the MWCNTs orientation at direct and alternating current showed that the conductivity of films obtained in a magnetic field significantly (by almost two orders of magnitude) exceeds the conductivity of control samples. The obtained results are analyzed on the basis of known models of electrical conductivity of nanocomposites with oriented MWCNTs. The degree of orientation of the MWCNTs during the curing of films in a magnetic field is estimated, taking into account the increase in the viscosity of the nanocomposite during the curing process.

scholarly journals The Effects of Multi-Walled Carbon Nanotubes and Steel Fibers on the AC Impedance and Electromagnetic Shielding Effectiveness of High-Performance, Fiber-Reinforced Cementitious Composites

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3591 ◽  
Author(s):  
Lee ◽  
Kim ◽  
Park
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
High Performance ◽  
Steel Fiber ◽  
Steel Fibers ◽  
Shielding Effectiveness ◽  
High Performance Fiber ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Electromagnetic Shielding Effectiveness

This study aimed to investigate the effect of multi-walled carbon nanotubes (MWCNTs) and steel fibers on the AC impedance and electromagnetic shielding effectiveness (SE) of a high-performance, fiber-reinforced cementitious composite (HPFRCC). The electrical conductivity of the 100 MPa HPFRCC with 0.30% MWCNT was 0.093 S/cm and that of the 180 MPa HPFRCC with 0.4% MWCNT and 2.0% steel fiber was 0.10 S/cm. At 2.0% steel fiber and 0.3% MWCNT contents, the electromagnetic SE values of the HPFRCC were 45.8 dB (horizontal) and 42.1 dB (vertical), which are slightly higher than that (37.9 dB (horizontal)) of 2.0% steel fiber content and that (39.2 dB (horizontal)) of 0.3% MWCNT content. The incorporation of steel fibers did not result in any electrical percolation path in the HPFRCC at the micro level; therefore, a high electrical conductivity could not be achieved. At the macro level, the proper dispersion of the steel fibers into the HPFRCC helped reflect and absorb the electromagnetic waves, increasing the electromagnetic SE. The incorporation of steel fibers helped improve the electromagnetic SE regardless of the formation of percolation paths, whereas the incorporation of MWCNTs helped improve the electromagnetic SE only when percolation paths were formed in the cement matrix.

scholarly journals Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2998
Author(s):  
Sheik Ambarine Banon Auckloo ◽  
Khanisya Palaniandy ◽  
Yew Mun Hung ◽  
Giuseppe Lazzara ◽  
Siang-Piao Chai ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Polymer Coatings ◽  
Nanocomposite Films ◽  
Coating Films ◽  
Water Contact ◽  
Degradation Temperature ◽  
Novel Approach ◽  
Multi Walled Carbon Nanotubes ◽  
Heat Exchanges ◽  
Walled Carbon Nanotubes

This study, for the first time, focused on the fabrication of nonporous polyurea thin films (~200 microns) using the electrospinning method as a novel approach for coating applications. Multi-walled carbon nanotubes (MWCNTs) and hydrophilic-fumed nanosilica (HFNS) were added separately into electrospun polyurea films as nano-reinforcing fillers for the enhancement of properties. Neat polyurea films demonstrated a tensile strength of 14 MPa with an elongation of 360%. At a loading of 0.2% of MWCNTs, the highest tensile strength of 21 MPa and elongation of 402% were obtained, while the water contact angle remained almost unchanged (89°). Surface morphology analysis indicated that the production of polyurea fibers during electrospinning bonded together upon curing, leading to a nonporous film. Neat polyurea exhibited high thermal resistance with a degradation temperature of 380 °C. Upon reinforcement with 0.2% of MWCNTs and 0.4% of HFNS, it increased by ~7 °C. The storage modulus increased by 42 MPa with the addition of 0.2% of MWCNTs, implying a superior viscoelasticity of polyurea nanocomposite films. The results were benchmarked with anti-corrosive polymer coatings from the literature, revealing that the production of nonporous polyurea coatings with robust strength, elasticity, and thermal properties was achieved. Electrospun polyurea coatings are promising candidates as flexible anti-corrosive coatings for heat exchanges and electrical wires.

scholarly journals Functionalized multi-walled carbon nanotubes and hydroxyapatite nanorods reinforced with polypropylene for biomedical application

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fahad Saleem Ahmed Khan ◽  
N. M. Mubarak ◽  
Mohammad Khalid ◽  
Rashmi Walvekar ◽  
E. C. Abdullah ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Mechanical Characteristics ◽  
Biomedical Application ◽  
Thermal Study ◽  
Melt Compounding ◽  
Industry Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
And Cartilage

AbstractModified multi-walled carbon nanotubes (f-MWCNTs) and hydroxyapatite nanorods (n-HA) were reinforced into polypropylene (PP) with the support of a melt compounding approach. Varying composition of f-MWCNTs (0.1–0.3 wt.%) and nHA (15–20 wt.%) were reinforced into PP, to obtain biocomposites of different compositions. The morphology, thermal and mechanical characteristics of PP/n-HA/f-MWCNTs were observed. Tensile studies reflected that the addition of f-MWCNTs is advantageous in improving the tensile strength of PP/n-HA nanocomposites but decreases its Young’s modulus significantly. Based on the thermal study, the f-MWCNTs and n-HA were known to be adequate to enhance PP’s thermal and dimensional stability. Furthermore, MTT studies proved that PP/n-HA/f-MWCNTs are biocompatible. Consequently, f-MWCNTs and n-HA reinforced into PP may be a promising nanocomposite in orthopedics industry applications such as the human subchondral bone i.e. patella and cartilage and fabricating certain light-loaded implants.

scholarly journals Enhancement of Electrical Conductivity of Aluminum-Based Nanocomposite Produced by Spark Plasma Sintering

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1150
Author(s):  
Nicolás A. Ulloa-Castillo ◽  
Roberto Hernández-Maya ◽  
Jorge Islas-Urbano ◽  
Oscar Martínez-Romero ◽  
Emmanuel Segura-Cárdenas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Spark Plasma Sintering ◽  
Experimental Tests ◽  
Powder Morphology ◽  
Plasma Sintering ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Ball Milling Technique ◽  
Walled Carbon Nanotubes

This article focuses on exploring how the electrical conductivity and densification properties of metallic samples made from aluminum (Al) powders reinforced with 0.5 wt % concentration of multi-walled carbon nanotubes (MWCNTs) and consolidated through spark plasma sintering (SPS) process are affected by the carbon nanotubes dispersion and the Al particles morphology. Experimental characterization tests performed by scanning electron microscopy (SEM) and by energy dispersive spectroscopy (EDS) show that the MWCNTs were uniformly ball-milled and dispersed in the Al surface particles, and undesirable phases were not observed in X-ray diffraction measurements. Furthermore, high densification parts and an improvement of about 40% in the electrical conductivity values were confirmed via experimental tests performed on the produced sintered samples. These results elucidate that modifying the powder morphology using the ball-milling technique to bond carbon nanotubes into the Al surface particles aids the ability to obtain highly dense parts with increasing electrical conductivity properties.

scholarly journals Cross-Linked Chitosan/Multi-Walled Carbon Nanotubes Composite as Ecofriendly Biocatalyst for Synthesis of Some Novel Benzil Bis-Thiazoles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1728
Author(s):  
Latifah A. Alshabanah ◽  
Sobhi M. Gomha ◽  
Laila A. Al-Mutabagani ◽  
Tariq Z. Abolibda ◽  
Nahed A. Abd El-Ghany ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Alternative Methods ◽  
Reaction Conditions ◽  
Chemical Structures ◽  
Weight Losses ◽  
Recyclable Catalysts ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Thermal Stability Of ◽  
Heterogeneous Biocatalyst

Aminohydrazide cross-linked chitosan (CLCS) and its MWCNTs (CLCS/MWCNTs) were formulated and utilized as a potent ecofriendly basic heterogeneous biocatalyst under ultrasonic irradiation for synthesis of two novel series of benzil bis-aryldiazenylthiazoles and benzil bis-arylhydrazonothiazolones from the reaction of benzil bis-thiosemicarbazone with 2-oxo-N′-arylpropanehydrazonoyl chlorides and ethyl 2-chloro-2-(2-phenylhydrazono) acetates, respectively. The chemical structures of the newly synthesized derivatives were elucidated by spectral data and alternative methods, where available. Additionally, their yield % was estimated using a traditional catalyst as TEA and green recyclable catalysts as CLCS and CLCS/MWCNTs composite in a comparative study. We observed that, under the same reaction conditions, the yield % of the desired products increased by changing TEA to CLCS then to CLCS/MWCNT from 72–78% to 79–83% to 84–87%, respectively. The thermal stability of the investigated samples could be arranged as CLCS/MWCNTs composite > CLCS > chitosan, where the weight losses of chitosan, CLCS and CLCS/MWCNTs composite at 500 °C were 65.46%, 57.95% and 53.29%, respectively.

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