scholarly journals Damage Detection of Carbon Nanotube Cementitious Composites Using Thermal and Electrical Resistance Properties

2021 ◽  
Vol 11 (7) ◽  
pp. 2955
Author(s):  
Heeyoung Lee ◽  
Wonjun Yu ◽  
Wonseok Chung
Keyword(s):  
Carbon Nanotube ◽  
Cement Paste ◽  
Electrical Resistance ◽  
Curing Period ◽  
Mwcnt Concentration ◽  
Experimental Parameters ◽  
Cement Based Materials ◽  
Multi Walled Carbon Nanotubes ◽  
Heat Property ◽  
Walled Carbon Nanotubes

This study aimed to detect damage based on thermal and electrical resistance properties by fabricating composites in which multi-walled carbon nanotubes (MWCNTs) and cement-based materials are mixed. The experimental parameters used were the cement-based material type, MWCNT concentration, curing period, and presence of damage. The experimental results showed that damage in cement paste can be detected using the heat property at every MWCNT concentration, and damage in mortar can be detected at MWCNT concentrations of ≤0.25 wt%. However, damage to concrete is difficult to detect using the heat property. Damage to cement paste, mortar, and concrete can be detected at every concentration using the electrical resistance property. Furthermore, field emission scanning electron microscopy (FE-SEM) results revealed uniformly dispersed MWCNTs inside the composites without agglomeration or the formation of carbon nanotube (CNT) networks.

Effect of Expanded Temperature on Microstructure of Carbon Nanotubes/Expanded Graphite Composites

2013 ◽  
Vol 716 ◽  
pp. 373-378
Author(s):  
Qian Zhang ◽  
Xin Bao Gao ◽  
Tian Peng Li
Keyword(s):  
Carbon Nanotubes ◽  
Composite Material ◽  
High Temperature ◽  
Carbon Nanotube ◽  
Physical Adsorption ◽  
Expanded Graphite ◽  
Graphite Flake ◽  
Graphite Composite ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Carbon nanotube/expanded graphite composite material was prepared by expanding the mixture of multi-walled carbon nanotubes and expansible graphite under the condition of high temperature. The microstructure and composition was studied by using SEM and XRD. The study shows that the tubular structure of carbon nanotubes in the composite material is changed by high temperature expanding process, and the microstructure is different with different expanding temperature. When the expanding temperature was 900°C, carbon nanotubes transformed, then attached to the surface of expanded graphite flake, so carbon nanotubes and expanding graphite combined strongly; globular carbon nanotubes attached to the surface of expanded graphite flake at the temperature of 700°C, both were combined much more strongly; carbon nanotubes retained the tube structure at the temperature of 500°C, combination was looser due to the simple physical adsorption. The result shows that the choice of expanding temperature has an important effect on microstructure of carbon nanotube/expanded graphite composite material.

The Effect of Nanotube Loading and Dispersion on the Three-Dimensional Nanostructure of Carbon Nanotube-Conducting Polymer Composite Films

2002 ◽  
Vol 739 ◽  
Author(s):  
Mark Hughes ◽  
George Z. Chen ◽  
Milo S. P. Shaffer ◽  
Derek J. Fray ◽  
Alan H. Windle
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Conducting Polymer ◽  
Polymer Composite ◽  
Electrochemical Polymerization ◽  
Composite Films ◽  
Three Dimensional ◽  
Ionic Diffusion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

ABSTRACTNanoporous composite films of multi-walled carbon nanotubes (MWNTs) and either polypyrrole (PPy) or poly(3-methylthiophene) (P3MeT) were grown using an electrochemical polymerization technique in which the nanotubes and conducting polymer were deposited simultaneously. The concentration and dispersion of MWNTs in the polymerization electrolyte was found to have a significant effect on the thickness of polymer coated on each MWNT and hence the loading of MWNTs in the films produced. It has been shown that for an increasing concentration of MWNTs in the polymerization electrolyte, the thickness of polymer coated on each MWNT decreases. This relationship made it possible to minimize ionic diffusion distances within the nanoporous MWNT-PPy films produced, reducing their electrical and ionic resistance and increasing their capacitance relative to similarly prepared pure PPy films.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

Pebax-1657 mixed matrix membrane containing surface modified multi-walled carbon nanotubes for gas separation

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79563-79577 ◽  
Author(s):  
S. A. Habibiannejad ◽  
A. Aroujalian ◽  
A. Raisi
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Functional Groups ◽  
Gas Separation ◽  
Mixed Matrix Membrane ◽  
Mixed Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Surface Modified ◽  
Walled Carbon Nanotubes

In this study different functional groups on the surface of carbon nanotube enhanced the performance of Pebax 1657/MWNTs.

Highly sensitive compression sensors using three-dimensional printed polydimethylsiloxane/carbon nanotube nanocomposites

2019 ◽  
Vol 30 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Mohammad Charara ◽  
Mohammad Abshirini ◽  
Mrinal C Saha ◽  
M Cengiz Altan ◽  
Yingtao Liu
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Carbon Nanotube ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Multi Walled Carbon Nanotube ◽  
Highly Sensitive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This article presents three-dimensional printed and highly sensitive polydimethylsiloxane/multi-walled carbon nanotube sensors for compressive strain and pressure measurements. An electrically conductive polydimethylsiloxane/multi-walled carbon nanotube nanocomposite is developed to three-dimensional print compression sensors in a freestanding and layer-by-layer manner. The dispersion of multi-walled carbon nanotubes in polydimethylsiloxane allows the uncured nanocomposite to stand freely without any support throughout the printing process. The cross section of the compression sensors is examined under scanning electron microscope to identify the microstructure of nanocomposites, revealing good dispersion of multi-walled carbon nanotubes within the polydimethylsiloxane matrix. The sensor’s sensitivity was characterized under cyclic compression loading at various max strains, showing an especially high sensitivity at lower strains. The sensing capability of the three-dimensional printed nanocomposites shows minimum variation at various applied strain rates, indicating its versatile potential in a wide range of applications. Cyclic tests under compressive loading for over 8 h demonstrate that the long-term sensing performance is consistent. Finally, in situ micromechanical compressive tests under scanning electron microscope validated the sensor’s piezoresistive mechanism, showing the rearrangement, reorientation, and bending of the multi-walled carbon nanotubes under compressive loads, were the main reasons that lead to the piezoresistive sensing capabilities in the three-dimensional printed nanocomposites.

scholarly journals Accelerated Shape Forming and Recovering, Induction, and Release of Adhesiveness of Conductive Carbon Nanotube/Epoxy Composites by Joule Heating

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1030 ◽  
Author(s):  
Petr Slobodian ◽  
Pavel Riha ◽  
Robert Olejnik ◽  
Jiri Matyas
Keyword(s):  
Carbon Nanotube ◽  
Joule Heating ◽  
Adhesive Bonding ◽  
Recovery Process ◽  
Epoxy Adhesive ◽  
Porous Network ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Dc Current ◽  
Walled Carbon Nanotubes

The versatile properties of a nanopaper consisting of a porous network of multi-walled carbon nanotubes were applied to enhance the mechanical and electrical properties of a thermosetting epoxy polymer. The embedded nanopaper proved useful both in the monitoring of the curing process of the epoxy resin by the self-regulating Joule heating and in the supervising of tensile deformations of the composite by detecting changes in its electrical resistance. When heated by Joule heating above its glass transition temperature, the embedded carbon nanotube nanopaper accelerated not only the modelling of the composites into various shapes, but also the shape recovery process, wherein the stress in the nanopaper was released and the shape of the composite reverted to its original configuration. Lastly, in comparison with its respective epoxy adhesive, the internally heated electro-conductive carbon nanotube nanopaper/epoxy composite not only substantially shortened curing time while retaining comparable strength of the adhesive bonding of the steel surfaces, but also enabled a release of such bonds by repeated application of DC current.

Self-assembly fabrication of a graphene/multi-walled carbon nanotube hybrid material for suppressing potential heat radiation and toxic effluent

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103365-103372 ◽  
Author(s):  
Lei Liu ◽  
Dong Wang ◽  
Yuan Hu
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Graphene Oxide ◽  
Carbon Nanotube ◽  
Hybrid Material ◽  
Self Assembly ◽  
Heat Radiation ◽  
Multi Walled Carbon Nanotube ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Negative graphene oxide was combined with positive chitosan-modified multi-walled carbon nanotubes in aqueous solution and then thermally reduced to fabricate a multi-walled carbon nanotube/graphene (MWCNT/G) hybrid material.

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