In-Situ Characterization of MWCNTs Reinforced Epoxy Nanocomposite Under Mechanical Load

Author(s):  
Xinnan Wang ◽  
Peng Cui ◽  
X. W. Tangpong

In this study, the mechanical properties of multi-walled carbon nanotubes (MWCNTs) reinforced epoxy nanocomposite were measured with the custom-built micro/nano three point bending tester mounted on an atomic force microscope (AFM). With in-situ observation of the AFM, the movement of an individual MWCNT on the sample surface was traced, captured, and quantified using the image correlation technique. The Halpin-Tsai and Hui-shia models were applied and compared with the experimental data. Results showed that the elastic modulus from the experiment is much lower than the predicted values from the two models. Detailed mechanical deformation behavior and MWCNT reinforcement mechanism were discussed.

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 510
Author(s):  
Gerald Singer ◽  
Philipp Siedlaczek ◽  
Gerhard Sinn ◽  
Patrick Kirner ◽  
Reinhard Schuller ◽  
...  

Sample preparation is an important step when testing the mechanical properties of materials. Especially, when carbon nanotubes (CNT) are added to epoxy resin, the increase in viscosity complicates the casting of testing specimens. We present a vacuum casting approach for different geometries in order to produce specimens from functional nanocomposites that consist of epoxy matrix and oxidized multi-walled carbon nanotubes (MWCNTs). The nanocomposites were characterized with various mechanical tests that showed improved fracture toughness, bending and tensile properties performance by addition of oxidized MWCNTs. Strengthening mechanisms were analyzed by SEM images of fracture surfaces and in-situ imaging by digital image correlation (DIC).


2011 ◽  
Vol 70 ◽  
pp. 249-254 ◽  
Author(s):  
Hiroyuki Toda ◽  
Kentaro Uesugi ◽  
Yoshio Suzuki ◽  
Masakazu Kobayashi

X-ray microtomography (XMT) has been utilized for the in-situ observation of various structural materials under external disturbance such as loading. In-situ XMT provides a unique possibility to access the three-dimensional (3D) character of internal microstructure and its time evolution behaviours non-destructively, thereby enabling advanced techniques for measuring local strain distribution. Local strain mapping is readily enabled by processing such high-resolution tomographic images either by the particle tracking technique or the digital image correlation technique. Procedures for tracking microstructural features which have been developed by the authors, have been applied to analyse localised deformation and damage evolution in a material. Typically several tens of thousands of microstructural features, such as particles and pores, are tracked in a tomographic specimen (0.2 - 0.3 mm3in volume). When a sufficient number of microstructural features is dispersed in 3D space, the Delaunay tessellation algorithm is used to obtain local strain distribution. With these techniques, 3D strain fields can be measured with reasonable accuracy. Even local crack driving forces, such as local variations in the stress intensity factor, crack tip opening displacement and J integral along a crack front line, can be measured from discrete crack tip displacement fields.


RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 1109-1114
Author(s):  
Peng Lv ◽  
Yeyun Meng ◽  
Lingxia Song ◽  
Hao Pang ◽  
Weiqu Liu

A robust self-supported electrode was prepared by a facile combination of ultrasonic dispersion and consequent in situ polymerization.


2021 ◽  
Author(s):  
Shankar S. Narwade ◽  
Shivsharan M. Mali ◽  
Bhaskar R. Sathe

A study on the in situ decoration of ethylenediamine (EDA) on acid functionalized multi-walled carbon nanotubes (O-MWCNTs) for overall water splitting reactions at all pH as an efficient and inexpensive metal-free multifunctional electrocatalyst.


2021 ◽  
Vol 9 ◽  
Author(s):  
R. He ◽  
L. He ◽  
B. Guan ◽  
C. M. Yuan ◽  
J. Xie ◽  
...  

Insight into the difference between the mechanical properties of rocks at low and in situ deep reservoir temperatures is vital for achieving a better understanding of fracking technologies with supercritical CO2 and liquid nitrogen. To address this issue, the fracking-related mechanical properties of the Shaximiao Formation sandstone (SS) were investigated through direct tension, uniaxial compression, and three-point bending fracture tests at a typical low temperature (Tlow) of −10°C and a reservoir temperature (Tin situ) of 70°C. The results showed that the tensile strength σt, compressive strength σc, and fracture toughness KIC of the SS were all higher at Tlow than at Tin situ, although to different extents. The KIC of the SS increased slightly more than σt at the lower temperature, while both σt and KIC of the SS increased significantly more than σc at the lower temperature. In addition to the strength, the stiffness (particularly the tensile stiffness) and the brittleness indices of SS were similarly higher at Tlow than at Tin situ. In situ monitoring using the digital image correlation technique revealed that a highly strained band (HSB) always appeared at the crack front. However, because of the inhomogeneous microstructure of the SS, the HSB did not always develop along the line connecting the notch tip to the loading point. This was a possible cause of the highly dispersed KIC values of the SS. The HSB at the crack front was notably narrower at Tlow than at Tin situ, suggesting that low temperatures suppress the plastic deformation of rocks and are therefore beneficial to reservoir stimulation.


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