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 ◽  
...  

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

2018 ◽  
Vol 52 (23) ◽  
pp. 3209-3217 ◽  
Author(s):  
Eduardo H Backes ◽  
Fabio R Passador ◽  
Christian Leopold ◽  
Bodo Fiedler ◽  
Luiz A Pessan

Epoxy/multi-wall carbon nanotubes and epoxy/multi-wall carbon nanotubes/mineral fillers nanocomposites were produced via in situ polymerization assisted by three-roll-milling. Epoxy/multi-wall carbon nanotubes nanocomposites presented very low electrical percolation threshold, near to 0.05 wt %. In this study, we used different mineral fillers, with different aspect ratios: calcium carbonate, montmorillonite, and sepiolite. We evaluated the effect of the addition of these fillers on electrical, thermal, and thermo-mechanical properties of epoxy/multi-wall carbon nanotubes nanocomposites. The addition of calcium carbonate in epoxy/multi-wall carbon nanotubes nanocomposites increased the electrical conductivity of this nanocomposite, due to volume exclusion effect. The addition of sepiolite decreased the loss factor and improved electrical constant, however, reduced the electrical conductivity in these nanocomposites, when compared to epoxy/multi-wall carbon nanotubes. Regarding thermal properties, no significant change in glass transition was observed. Thermo-mechanical analysis for nanocomposites showed slight changes in tan (δ) and storage modulus, which is related to the interaction between epoxy, multi-wall carbon nanotubes and mineral fillers.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  

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.


2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Eric Devaux ◽  
Carole Aubry ◽  
Christine Campagne ◽  
Maryline Rochery

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.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4149
Author(s):  
Laura M. Echeverry-Cardona ◽  
Natalia Álzate ◽  
Elisabeth Restrepo-Parra ◽  
Rogelio Ospina ◽  
Jorge H. Quintero-Orozco

This study shows the energy optimization and stabilization in the time of solutions composed of H2O + TX-100 + Multi-Wall Carbon Nanotubes (MWCNTs), used to improve the mechanical properties of Portland cement pastes. For developing this research, sonication energies at 90, 190, 290, 340, 390, 440, 490 and 590 J/g are applied to a colloidal substance (MWCNTs/TX-100 + H2O) with a molarity of 10 mM. Raman spectroscopy analyses showed that, for energies greater than 440 J/g, there are ruptures and fragmentation of the MWCNTs; meanwhile at energies below 390 J/g, better dispersions are obtained. The stability of the dispersion over time was evaluated over 13 weeks using UV-vis spectroscopy and Zeta Potential. With the most relevant data collected, sonication energies of 190, 390 and 490 J/g, at 10 mM were selected at the first and the fourth week of storage to obtain Portland cement specimens. Finally, we found an improvement of the mechanical properties of the samples built with Portland cement and solutions stored for one and four weeks; it can be concluded that the MWCNTs improved the hydration period.


2012 ◽  
Vol 221 ◽  
pp. 351-358 ◽  
Author(s):  
Bernardo Marinho ◽  
Marcos Ghislandi ◽  
Evgeniy Tkalya ◽  
Cor E. Koning ◽  
Gijsbertus de With

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