scholarly journals A Study on Mechanical Characteristics of Cement Composites Fabricated with Nano-Silica and Carbon Nanotube

2020 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Ali Raza ◽  
Manan Bhandari ◽  
Hyeong-Ki Kim ◽  
Hyeong-Min Son ◽  
Baofeng Huang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Mechanical Strength ◽  
Cement Composites ◽  
Nano Silica ◽  
Dense Microstructure ◽  
Strength Tests ◽  
Multi Walled Carbon Nanotubes ◽  
Compressive And Flexural Strengths ◽  
Walled Carbon Nanotubes

In this study, cement composites were fabricated with various contents of added nano-silica (NS) and multi-walled carbon nanotubes (MWNTs). The compressive and flexural strengths of the resultant cement composites were examined. To explore the microstructures and MWNT distribution, electrical conductivity tests, and scanning electron microscopy were conducted. In addition, the strength results were analyzed based on thermal analysis and porosity evaluations. The electrical conductivity results indicated that MWNTs were satisfactorily distributed in the cement composites. In the mechanical strength tests, the composite with a 0.6% MWNT and 5% NS content and another with a 0.3% MWNT and 5% NS content yielded enhancements in the compressive and flexural strengths of 17.2% and 52% compared with the control samples, respectively. However, composites containing relatively large amounts of both NS and MWNTs showed degradation in the mechanical strength. The enhancement or degradation of the strength was supported by porosity evaluations and thermal analysis results. In particular, the degradation of the strength due to the incorporation of large amounts of both MWNTs and NS was explained by thermogravimetric analysis, which indicated a limited generation of calcium silicate hydrate (C-S-H) hydration products. The lower generation of C-S-H was likely due to the dense microstructure of MWNT/NS-incorporated cement hindering the reactions between calcium hydroxide and the NS.

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 Magnesium Oxychloride Cement Composites with MWCNT for the Construction Applications

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 484
Author(s):  
Michal Lojka ◽  
Anna-Marie Lauermannová ◽  
David Sedmidubský ◽  
Milena Pavlíková ◽  
Martina Záleská ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Mechanical Resistance ◽  
Cement Composites ◽  
Multi Walled Carbon Nanotubes ◽  
The Subject ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Phase And Chemical Composition ◽  
Walled Carbon Nanotubes ◽  
Oxychloride Cement

In this contribution, composite materials based on magnesium oxychloride cement (MOC) with multi-walled carbon nanotubes (MWCNTs) used as an additive were prepared and characterized. The prepared composites contained 0.5 and 1 wt.% of MWCNTs, and these samples were compared with the pure MOC Phase 5 reference. The composites were characterized using a broad spectrum of analytical methods to determine the phase and chemical composition, morphology, and thermal behavior. In addition, the basic structural parameters, pore size distribution, mechanical strength, stiffness, and hygrothermal performance of the composites, aged 14 days, were also the subject of investigation. The MWCNT-doped composites showed high compactness, increased mechanical resistance, stiffness, and water resistance, which is crucial for their application in the construction industry and their future use in the design and development of alternative building products.

scholarly journals Synthesis, Characterization and Study of DC Electrical Conductivity of Poly[MWCNT/Imidoselenium] Composite

2019 ◽  
Author(s):  
Abeer O. Obeid ◽  
Fatma Al-Yusufy ◽  
Sama A Al-Aghbari ◽  
omar alshujaa ◽  
Yassin Gaber ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Selenium Dioxide ◽  
Chemical Functionalization ◽  
Dc Electrical Conductivity ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

<p>The chemical functionalization of amino multi-walled carbon nanotubes (MWCNT-NH<sub>2</sub>) by selenium dioxide (SeO<sub>2</sub>) was used to produce Poly [MWCNT/Imidoselenium] composite. The prepared poly-composite was characterized by FTIR, SEM, TEM, XRD, UV, DSC and TGA. The DC electrical conductivity of poly-composite was 4.3×10<sup>-4</sup> S/cm due to the interaction between the nanotubes. </p>

Development of Carbon Nanotube Reinforced Conductive Polymer Composites for PEM Fuel Cells

2012 ◽  
Vol 729 ◽  
pp. 260-265
Author(s):  
M. Olah ◽  
Ferenc Ronkay
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composites ◽  
Filler Content ◽  
Conductive Polymer ◽  
High Viscosity ◽  
Pem Fuel Cells ◽  
Conductive Polymer Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Matrix Compound ◽  
Walled Carbon Nanotubes

Investigation of conductive polymer composites have been carried out using polypropylene (PP) and polyphenylene sulfonate (PPS) for matrix compound and graphite, carbon black and multi walled carbon nanotubes (MWCNT) for fillers. The comparison of these matrix materials with respect to the resulting electrical conductivity were investigated in depth. The effect of quantity of nanotubes and their dispersion on electrical conductivity and formability was also investigated. It has been found that PPS composites show much higher conductivity, however the high temperature needed for forming, and high viscosity in case of high filler content (50 wt% <) make the processing difficult, therefore the injection molding of the resulting material is currently not possible. Furthermore in contradiction to the literature the addition of MWCNT did not raise the conductivity significantly, therefore the focus have been kept on filler content instead.

The effect of functionalization on structure and electrical conductivity of multi-walled carbon nanotubes

2008 ◽  
Vol 10 (S1) ◽  
pp. 77-88 ◽  
Author(s):  
Cher Hon Lau ◽  
Raoul Cervini ◽  
Stephen R. Clarke ◽  
Milena Ginic Markovic ◽  
Janis G. Matisons ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

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.

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