(Invited) Periodic Buckling as Predominant Deformation Mechanism in Carbon Nanotube Foams as Revealed by In situ Uniaxial Compression Experiments and Modeling

1970 ◽  
Vol 26 ◽  
pp. 22-30
Author(s):  
Rameshwor Adhikari ◽  
Reinhold Godehardt ◽  
Werner Lebek ◽  
Goerg H. Michler ◽  
Petra Potschke

Deformation behavior of nanocomposites based on an ethylene/1-octene copolymerand multiwalled carbon nanotube (CNT) was investigated by means of an atomic forcemicroscope (AFM). Via a special tensile module integrated to an optical microscope, it waspossible to record the stress-strain diagrams of the composites using miniaturized tensilespecimens. By analyzing strain induced structural changes occurring at differentsuccessively applied loads, it was possible to correlate the deformation mechanismsoccurring on various length scales (i.e. at macroscopic, microscopic as well as nanoscopiclevels) to different degrees of deformation. It was noteworthy that, contrasting theproperties of other nanocomposites described so far in the literature, both the strength andtoughness of the composites were found to enhance. It was found that the deformation of thecomposite on nanoscopic scale was inhomogeneous owing to anisotropic properties of theCNTs and their alignments. After unloading the sample, the nanostructure of the originalmaterial was fully regenerated explaining the macroscopically observed elastomericproperties.Keywords: Ethylene/1-octene copolymer; CNT; Deformation mechanism; AFM; In situ deformation testsDOI: 10.3126/jncs.v26i0.3626Journal of Nepal Chemical SocietyVol. 26, 2010Page: 22-30


2021 ◽  
Vol 202 ◽  
pp. 109535
Author(s):  
Yadong Wu ◽  
Xiuyan Cheng ◽  
Shaoyun Chen ◽  
Bo Qu ◽  
Rui Wang ◽  
...  

2020 ◽  
Vol 9 (1) ◽  
pp. 478-488 ◽  
Author(s):  
Yun-Fei Zhang ◽  
Fei-Peng Du ◽  
Ling Chen ◽  
Ka-Wai Yeung ◽  
Yuqing Dong ◽  
...  

AbstractElectroactive hydrogels have received increasing attention due to the possibility of being used in biomimetics, such as for soft robotics and artificial muscles. However, the applications are hindered by the poor mechanical properties and slow response time. To address these issues, in this study, supramolecular ionic polymer–carbon nanotube (SIPC) composite hydrogels were fabricated via in situ free radical polymerization. The polymer matrix consisted of carbon nanotubes (CNTs), styrene sulfonic sodium (SSNa), β-cyclodextrin (β-CD)-grafted acrylamide, and ferrocene (Fc)-grafted acrylamide, with the incorporation of SSNa serving as the ionic source. On applying an external voltage, the ions accumulate on one side of the matrix, leading to localized swelling and bending of the structure. Therefore, a controllable and reversible actuation can be achieved by changing the applied voltage. The tensile strength of the SIPC was improved by over 300%, from 12 to 49 kPa, due to the reinforcement effect of the CNTs and the supramolecular host–guest interactions between the β-CD and Fc moieties. The inclusion of CNTs not only improved the tensile properties but also enhanced the ion mobility, which lead to a faster electromechanical response. The presented electro-responsive composite hydrogel shows a high potential for the development of robotic devices and soft smart components for sensing and actuating applications.


Nanoscale ◽  
2021 ◽  
Author(s):  
Qiufan Wang ◽  
Jiaheng Liu ◽  
Guofu Tian ◽  
Daohong Zhang

The rapid development of human-machine interface and artificial intelligence is dependent on flexible and wearable soft devices such as sensors and energy storage systems. One of the key factors for...


2009 ◽  
Vol 1240 ◽  
Author(s):  
Ji-Ye Kang ◽  
Su-Mi Eo ◽  
Loon-Seng Tan ◽  
Jong-Beom Baek

AbstractSingle-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) were functionalized with 3,4-diaminobenzoic acid via “direct” Friedel-Crafts acylation reaction in PPA/P2O5 to afford ortho-diamino-functionalized SWCNT (DIF-SWCNT) and MWCNT (DIF-MWCNT). The resultant DIF-SWCNT and DIF-MWCNT showed improved solubility and dispersibility. To improve interfacial adhesion between CNT and polymer matrix, the grafting of ABPBI onto the surface of DIF-SWCNT (10 wt%) or DIF-MWCNT (10 wt%) was conducted by simple in-situ polymerization of AB monomer, 3,4-diaminobenzoic acid dihydrochloride, in PPA. The resultant ABPBI-g-MWCNT and ABPBI-g-SWCNT showed improved the mechanical and electrical properties.


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