scholarly journals Strengthening Mechanism of Electrothermal Actuation in the Epoxy Composite with an Embedded Carbon Nanotube Nanopaper

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1529
Author(s):  
Petr Slobodian ◽  
Pavel Riha ◽  
Robert Olejnik ◽  
Jiri Matyas

We assessed an effect of an embedded electro-conductive multiwalled carbon nanotube nanopaper in an epoxy matrix on the release of the frozen actuation force and the actuation torque in the carbon nanotube nanopaper/epoxy composite after heating above its glass transition temperature. The presence of the nanopaper augmented the recovery of the actuation stress by the factor of two in comparison with the pure epoxy strips. We proposed a procedure that allowed us to assess this composite strengthening mechanism. The strengthening of the composite was attributed to the interlocking of the carbon nanotubes with the epoxy. When reheated, the composite samples, which contained stretched mutually intertwined nanotubes and epoxy segments, released a greater actuation stress then the epoxy samples, which comprised of less elastic networks of crosslinked segments of pure epoxy.

2008 ◽  
Vol 23 (11) ◽  
pp. 2975-2983 ◽  
Author(s):  
Qunfeng Cheng ◽  
Jiaping Wang ◽  
Kaili Jiang ◽  
Qunqing Li ◽  
Shoushan Fan

A method to fabricate continuous and aligned multiwalled carbon nanotube (CNT)/epoxy composites is presented in this paper. CNT/epoxy composites were made by infiltrating an epoxy resin into a stack of continuous and aligned multiwalled CNT sheets that were drawn from super-aligned CNT arrays. By controlling the amount and alignment of the continuous multiwalled CNT sheets, a CNT/epoxy composite with high content of well-dispersed CNTs can be obtained. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results show that the thermal stability of these CNT/epoxy composites was not affected by the addition of CNTs. The mechanical properties and electrical properties of the CNT/epoxy composites were dramatically improved compared to pure epoxy, suggesting that the CNT/epoxy composites can serve as multifunctional materials with combined mechanical and physical properties.


2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Waris Obitayo ◽  
Tao Liu

The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.


2014 ◽  
Vol 38 (10) ◽  
pp. 4799-4806 ◽  
Author(s):  
Md. Shahinul Islam ◽  
Won San Choi ◽  
Tae Sung Bae ◽  
Young Boo Lee ◽  
Ha-Jin Lee

We report a simple protocol for the fabrication of multiwalled carbon nanotubes (MWCNTs) with a neuron-like structure for loading ultra-high densities of metal nanoparticles (NPs).


2003 ◽  
Vol 791 ◽  
Author(s):  
P. C. Ramamurthy ◽  
W. R. Harrell ◽  
R. V. Gregory ◽  
B. Sadanadan ◽  
A. M. Rao

ABSTRACTHigh molecular weight polyaniline / multi-walled carbon nanotube composite films were fabricated using solution processing. Composite films with various weight percentages of multiwalled carbon nanotubes were fabricated. Physical properties of these composites were analyzed by thermogravimetric analysis, tensile testing, and scanning electron microscopy. These results indicate that the addition of multiwalled nanotubes to polyaniline significantly enhances the mechanical properties of the films. In addition, metal–semiconductor (composite) (MS) contact devices were fabricated, and it was observed that the current level in the films increased with increasing multiwalled nanotube content. Furthermore, it was observed that polyaniline containing one weight percent of carbon nanotubes appears to be the most promising composition for applications in organic electronic devices.


RSC Advances ◽  
2017 ◽  
Vol 7 (33) ◽  
pp. 20422-20429 ◽  
Author(s):  
Tongfei Wu ◽  
Biqiong Chen

Viscoelastic rubber reinforced by multiwalled carbon nanotubes exhibited rapid, autonomous, mechanically and electrically self-healing properties and piezoresistive behavior.


Author(s):  
Cheng-Hsiung Kuo ◽  
Hwei-Ming Huang

This study measures the thermal conductivity of the MWNT/epoxy bulk composite material to enhance the heat transfer rates of the high power LED device. In this study, three different weight percentages (0.0 wt%, 0.3 wt% and 0.5 wt%) of MWNT/Epoxy composite and five different heat generating rates were employed for the investigation. The case of pure epoxy resins (0.0 wt%) was used as a reference. The responding time and the thermal conductivity of the composites were evaluated. The results show that the response is the fastest for composite with 0.5 wt% MWNT among three composites studied herein. The responses of the 0.3%wt and 0.5%wt composite are increased by 14.3%∼26.7% relative to that of the pure epoxy. Compare with that of the pure epoxy, the thermal conductivities for the cases with 0.3 wt% and 0.5 wt% MWNT/epoxy composite are increased by 15.9%∼44.9%. Further, the thermal conductivity does not vary with temperature for the temperature range studied herein. In the present study, the thermal conductivity of the composite material is found to increase mildly with the increasing heat generation rate.


Author(s):  
Yung J. Jung ◽  
Laila Jaber-Ansari ◽  
Xugang Xiong ◽  
Sinan Mu¨ftu¨ ◽  
Ahmed Busnaina ◽  
...  

We will present a method to fabricate a new class of hybrid composite structures based on highly organized multiwalled carbon nanotube (MWNT) and singlewalled carbon nanotube (SWNT) network architectures and a polydimethylsiloxane (PDMS) matrix for the prototype high performance flexible systems which could be used for many daily-use applications. To build 1–3 dimensional highly organized network architectures with carbon nanotubes (both MWNT and SWNT) in macro/micro/nanoscale we used various nanotube assembly processes such as selective growth of carbon nanotubes using chemical vapor deposition (CVD) and self-assembly of nanotubes on the patterned trenches through solution evaporation with dip coating. Then these vertically or horizontally aligned and assembled nanotube architectures and networks are transferred in PDMS matrix using casting process thereby creating highly organized carbon nanotube based flexible composite structures. The PDMS matrix undergoes excellent conformal filling within the dense nanotube network, giving rise to extremely flexible conducting structures with unique electromechanical properties. We will demonstrate its robustness under large stress conditions, under which the composite is found to retain its conducting nature. We will also demonstrate that these structures can be directly utilized as flexible field-emission devices. Our devices show some of the best field enhancement factors and turn-on electric fields reported so far.


2008 ◽  
Vol 42 (16) ◽  
pp. 6100-6104 ◽  
Author(s):  
Beatriz Suárez ◽  
Yolanda Moliner-Martínez ◽  
Soledad Cárdenas ◽  
Bartolomé M. Simonet ◽  
Miguel Valcárcel

2016 ◽  
Vol 52 (22) ◽  
pp. 4195-4198 ◽  
Author(s):  
Filippo S. Boi ◽  
Jian Guo ◽  
Shanling Wang ◽  
Yi He ◽  
Gang Xiang ◽  
...  

A key challenge in the fabrication of ferromagnetically filled carbon-nanotube buckypapers in the presence of Cl-radicals is the achievement of a preferential horizontal nanotube-alignment.


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