scholarly journals Self-sensing performance of metakaolin geopolymer with carbon nanotubes subjected to repeated compressive loading

2021 ◽  
Vol 1209 (1) ◽  
pp. 012043
Author(s):  
C Mizerová ◽  
P Rovnaník ◽  
I Kusák ◽  
P Schmid
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Continuous Monitoring ◽  
Compressive Loading ◽  
Conductive Filler ◽  
Applied Loading ◽  
Interest In Research ◽  
Metakaolin Geopolymer ◽  
Sensing Performance

Abstract Alkaline activated binders showing enhanced piezoresistive properties have recently attracted increased interest in research of their application in smart self-sensing components. This study is focused on metakaolin geopolymer mortar doped with 0.05 and 0.10% carbon nanotubes, a conductive filler that effectively increases electrical conductivity without considerable deterioration of mechanical properties. Self-sensing performance of composites incorporated with electrodes and attached strain gauge was tested during different regimes of compressive loading cycles with continuous monitoring of strain and resistivity. Although the differences in sensitivity and repeatability were observed, all samples including the reference material have shown good response to applied loading.

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

PLA/Carbon Nanotubes Multifilament Yarns for Relative Humidity Textile Sensor

2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Eric Devaux ◽  
Carole Aubry ◽  
Christine Campagne ◽  
Maryline Rochery
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Relative Humidity ◽  
Melt Spinning ◽  
Flexible Sensor ◽  
Spinning Process ◽  
Textile Sensor ◽  
Multifilament Yarns

Polylactide (PLA) was mixed with 4 wt.% of carbon nanotubes (CNTs) to produce electrical conductive multifilament yarns by melt spinning process for humidity detection. Thanks to a variation of electrical conductivity, this flexible sensor could detect the moisture presence. The introduction of plasticizer was necessary to ensure higher fluidity and drawability of the blend during the spinning process. The plasticizer modifies the crystallinity and the mechanical properties of the yarns. The effectiveness of this sensor (PLA/4 wt.% CNTs fibres) sensitive to humidity, is optimal when the spinning conditions are adapted. In this way, the temperature and the rate of the drawing roll were reduced. The influence of these parameters on the crystallinity, the mechanical properties and the sensitivity of the yarns were studied. Once the appropriate spinning conditions found, one humidity sensitive yarn was processed and the repeatability and efficient reversibility of its sensitivity were highlighted.

scholarly journals Assessing the Critical Multifunctionality Threshold for Optimal Electrical, Thermal, and Nanomechanical Properties of Carbon Nanotubes/Epoxy Nanocomposites for Aerospace Applications

Aerospace ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 7 ◽  
Author(s):  
Aikaterini-Flora Trompeta ◽  
Elias Koumoulos ◽  
Sotirios Stavropoulos ◽  
Theodoros Velmachos ◽  
Georgios Psarras ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Critical Concentration ◽  
Epoxy Composites ◽  
Micro Computed Tomography ◽  
Epoxy Nanocomposites ◽  
Aerospace Structures ◽  
Nanomechanical Properties

Epoxy composites are widely used in primary aerospace structures, where high impact damage properties are necessary. However, challenges appear when multiple functionalities, including electrical and thermal conductivity, are needed in parallel with increased mechanical properties. The current study aims at the assessment of a critical concentration of multiwalled carbon nanotubes (MWCNTs), incorporated in epoxy resin, which will indicate a threshold for optimal electrical, thermal and mechanical properties. For the evaluation of this optimal concentration, electrical conductivity, thermal stability and nanomechanical properties (Young modulus and nanohardness) have been assessed, for epoxy nanocomposites with 0 to 15 parts per hundred resin per weight (phr) MWCNTs. Percolation theory was applied to study the electrical conductivity for different contents of MWCNTs in the epoxy nanocomposite system. Thermogravimetric analysis was employed for the assessment of the epoxy composites’ thermal properties. Nanohardness and elastic modulus were measured, and the hardness versus modulus index was calculated. Emphasis was given to the dispersion of MWCNTs in the epoxy matrix, which was assessed by both microscopy techniques and X-ray micro–computed tomography. A correlation between the optimum dispersion and MWCNTs content in terms of electrical conductivity, thermal stability, and nanomechanical properties revealed a threshold concentration at 3 phr, allowing the manufacturing of aerospace structures with multifunctional properties.

Modification of Electrical and Mechanical Properties of Single Wall Carbon Nanotubes by Reaction with SOCl2

2003 ◽  
Vol 772 ◽  
Author(s):  
Urszula Dettlaff-Weglikowska ◽  
Viera Skakalova ◽  
Ralf Graupner ◽  
Lothar Ley ◽  
Siegmar Roth
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Functional Groups ◽  
Carboxyl Groups ◽  
Single Wall Carbon Nanotubes ◽  
Chemical Methods ◽  
Chemical Functionalization ◽  
Single Wall Carbon ◽  
Bucky Paper

AbstractAttaching chemical functional groups to single wall carbon nanotubes (SWNTs) has been achieved by chemical methods. Oxidized purified nanotubes have been treated by thionyl chloride in order to convert carboxyl groups into acylchloride groups. We observe by XPS and EDX that not only chlorine atoms but sulphur containing functional groups are covalently bound to the nanotubes. This chemical functionalization also causes significant changes in the electrical and mechanical properties of the nanotubes. The electrical conductivity measured on mats (bucky paper) increases from 500 S/cm in pristine tubes to 2500 S/cm in modified tubes. Similarly, the Young's modulus of bucky paper increases by about 100 %.

Enhanced electrical conductivity and piezoresistive sensing in multi-wall carbon nanotubes/polydimethylsiloxane nanocomposites via the construction of a self-segregated structure

Nanoscale ◽  
2017 ◽  
Vol 9 (31) ◽  
pp. 11017-11026 ◽  
Author(s):  
Ming Wang ◽  
Kai Zhang ◽  
Xin-Xin Dai ◽  
Yin Li ◽  
Jiang Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Multi Wall Carbon Nanotubes ◽  
Segregated Structure

Self-segregated PDMS/MWCNT nanocomposites exhibit high piezoresistive sensitivity, low percolation threshold and an enhanced mechanical properties.

Multiwalled Carbon Nanotubes-Incorporated Polyurethane Nanocomposites

2008 ◽  
Vol 47-50 ◽  
pp. 1109-1112
Author(s):  
Ye Seul Kim ◽  
Rira Jung ◽  
Hun Sik Kim ◽  
Hyoung Joon Jin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Multiwalled Carbon Nanotubes ◽  
Physical And Mechanical Properties ◽  
High Reactivity ◽  
Multiwalled Carbon ◽  
Contact Points ◽  
Conductive Fillers

Polyurethane was used as adhesive due to high reactivity, high flexibility, and mechanical properties. Electrically conductive adhesives (ECAs) are an alternative to tin-lead solder in order to provide conductive paths between two electrical device components, which typically consist of a polymeric resin that contributes physical and mechanical properties, and conductive fillers. However, ECAs have low electrical conductivity and unstable network due to large contact points of the few micrometer-sized metal particles. In order to overcome these restrictions, multiwalled carbon nanotubes (MWCNTs) with high aspect ratio and smaller nanometer scale can be used as conductive fillers. In this study, ECAs were based on polyurethane filled with two kinds of fillers, raw MWCNTs and acid treated MWCNTs, respectively. Electrical conductivity was measured by using four-point probe. Morphology and dispersibility of fillers were observed by scanning electron microscopy and transmission electron microscopy.

Mechanical properties of a carbon fabric-reinforced epoxy composite with carbon nanotubes and a flame retardant

2016 ◽  
Vol 7 (5) ◽  
pp. 630-644 ◽  
Author(s):  
Martin Kadlec ◽  
Robin Hron ◽  
Liberata Guadagno
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Fibre ◽  
Flame Retardant ◽  
Mechanical Test ◽  
Fibre Volume ◽  
Morphological Properties ◽  
Flame Resistance ◽  
Content Type

Purpose The purpose of this paper is to present the mechanical and morphological characterization of new multifunctional carbon fibre-reinforced composites (CFRCs) that are able to overcome two of the main drawbacks of aeronautical composite materials: reduced electrical conductivity and poor flame resistance. Multiwall carbon nanotubes and glycidyl POSS (GPOSS) were used to simultaneously enhance electrical conductivity and flame resistance. The effect of these two combined components on the mechanical and morphological properties of the manufactured CFRCs was analysed. Design/methodology/approach This paper describes the mechanical test results obtained for interlaminar shear strength, three-point bending, and tensile and fracture toughness in mode I tests. Carbon fibre-reinforced epoxy resin plates were manufactured in two series with blank resin and CNT+flame retardant GPOSS-enhanced resin. Findings The mechanical properties were decreased by no more than 10 per cent by combined influence of CNTs and GPOSS. Agglomerates of CNTs were observed using scanning electron microscopy. The agglomerates were large enough to be visible to the naked eye as black spots on the delaminated fracture surface. The decrease of the mechanical properties could be caused by these agglomerates or by a changed fibre volume content that was affected by the difficult infusion procedure due to high resin viscosity. Originality/value If we consider the benefit of CNTs as a nanofiller to increase electrical conductivity and the GPOSS as a component to increase the flame resistance of the resin, the decrease of strength seems to be insignificant.

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