scholarly journals Mechanical characterization of sol-gel alumina-based ceramics with intragranular reinforcement of multiwalled carbon nanotubes

2020 ◽  
Vol 46 (12) ◽  
pp. 19723-19730 ◽  
Author(s):  
Pedro Rivero-Antúnez ◽  
Rafael Cano-Crespo ◽  
Luis Esquivias ◽  
Nicolás de la Rosa-Fox ◽  
Camilo Zamora-Ledezma ◽  
...  
2018 ◽  
Vol 126 (12) ◽  
pp. 984-991 ◽  
Author(s):  
Yusuf TIJJANI ◽  
Faizah MOHD YASIN ◽  
Mohd Halim S. ISMAIL ◽  
Azmah Hanim MOHAMED ARIFF

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4283 ◽  
Author(s):  
Nataliya A. Sakharova ◽  
André F. G. Pereira ◽  
Jorge M. Antunes ◽  
José V. Fernandes

The elastic properties of armchair and zigzag multiwalled carbon nanotubes were investigated under tensile, bending, and torsion loading conditions. A simplified finite element model of the multiwalled carbon nanotubes, without taking into account the van der Waals interactions between layers, was used to assess their tensile, bending, and torsional rigidities and, subsequently, Young’s and shear moduli. Relationships between the tensile rigidity and the squares of the diameters of the outer and inner layers in multiwalled carbon nanotubes, and between the bending and torsional rigidities with the fourth powers of the diameters of the outer and inner layers, were established. These relationships result in two consistent methods, one for assessment to the Young’s modulus of armchair and zigzag multiwalled carbon nanotubes, based on tensile and bending rigidities, and the other to evaluate shear modulus using tensile, bending, and torsional rigidities. This study provides a benchmark regarding the determination of the mechanical properties of nonchiral multiwalled carbon nanotubes by nanoscale continuum modeling approach.


2007 ◽  
Vol 40 (4) ◽  
pp. 997-1003 ◽  
Author(s):  
Seth D. McCullen ◽  
Derrick R. Stevens ◽  
Wesley A. Roberts ◽  
Satyajeet S. Ojha ◽  
Laura I. Clarke ◽  
...  

2016 ◽  
Vol 30 (3) ◽  
pp. 404-415 ◽  
Author(s):  
Hongyan Xie ◽  
Qing Ye ◽  
Jin Liu ◽  
Guanglian Zhou ◽  
Wei Liu ◽  
...  

Two kinds of multiwalled carbon nanotubes/silica nanohybrids (CNTs/SiO2) were synthesized via a sol–gel method by coating SiO2 on the surfaces of CNTs that had been functionalized with poly(sodium- p-styrenesulfonate) (PSS). The influence of the nanohybrids on the thermal properties of poly(vinyl alcohol) (PVA) and polyurethane (PU) composites was investigated. Characterization of CNTs/SiO2 nanohybrids, elucidated with scanning electron microscopy and X-ray diffraction, showed that PSS played a key role in the final morphology and resulted in a “core/shell” and “candied haws on a stick”-like structure. The thermal degradation and thermo-oxidation of PVA and PU composites evaluated by thermogravimetic analyses suggested that the thermal properties of PVA/(CNTs/SiO2) composites were improved at relative high temperature range when compared with pure PVA, and the improvement mainly depended on the loading fraction of the nanohybrids, while for PU/(CNTs/SiO2) composites, a small fraction of the nanohybrids increased the materials thermal properties, but the improvements were influenced by the type of CNTs/SiO2 nanohybrids.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 285
Author(s):  
Lingfei Li ◽  
Qiu Sun ◽  
Xiangqun Chen ◽  
Zhaohua Jiang ◽  
Yongjun Xu

The low dielectric constant of the nonpolar polymer poly(1-butene) (PB-1) limits its application as a diaphragm element in energy storage capacitors. In this work, Ba(Zr0.2Ti0.8)O3-coated multiwalled carbon nanotubes (BZT@MWCNTs) were first prepared by using the sol–gel hydrothermal method and then modified with polydopamine (PDA) via noncovalent polymerization. Finally, PB-1 matrix composite films filled with PDA-modified BZT@MWCNTs nanoparticles were fabricated through a solution-casting method. Results indicated that the PDA-modified BZT@MWCNTs had good dispersion and binding force in the PB-1 matrix. These characteristics improved the dielectric and energy storage performances of the films. Specifically, the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film exhibited the best dielectric performance. At 1 kHz, the dielectric constant of this film was 25.43, which was 12.7 times that of pure PB-1 films. Moreover, its dielectric loss was 0.0077. Furthermore, under the weak electric field of 210 MV·m−1, the highest energy density of the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film was 4.57 J·cm−3, which was over 3.5 times that of PB-1 film (≈1.3 J·cm−3 at 388 MV·m−1).


Nano Letters ◽  
2007 ◽  
Vol 7 (4) ◽  
pp. 1086-1090 ◽  
Author(s):  
Paul Rice ◽  
T. Mitch Wallis ◽  
Stephen E. Russek ◽  
Pavel Kabos

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