Synergistic effects of double-walled carbon nanotubes and nanoclays on mechanical, electrical and piezoresistive properties of epoxy based nanocomposites

• Published in: Composites science and technology 2020-11, Vol.200, p.108459, Article 108459
• Main Authors: Esmaeili, A., Sbarufatti, C., Jiménez-Suárez, A., Hamouda, A.M.S., Rovatti, L., Ureña, A.
• Format: Article
• Language: English
• Subjects: Carbon; Carbon nanotubes; Conductivity; Crack bridging; Electrical resistivity; Electro-mechanical behaviour; Epoxy resins; Fracture testing; Mechanical properties; Microstructural analysis; Multi wall carbon nanotubes; Nano composites; Nanoclays; Nanocomposites; Nanotubes; Piezoresistivity
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2020.108459

Many studies performed on multifunctional properties of epoxy based nanocomposites reinforced with carbon nanotubes (CNTs) and nanoclay (NC) whereas their synergetic effects on piezoresistive behaviour of ternary state nanocomposites still remains unaddressed. Therefore, the hybrid effects of double-walled CNTs (DWCNTs) and NC on the mechanical, electrical and piezoresistive performances of the epoxy were addressed in this study. Nanocomposites were prepared in two different states, i.e. the binary state (DWCNTs/epoxy) and the ternary states (DWCNTs-NC/epoxy). SEM, FESEM, and XRD were used for the microstructural analysis of the materials while tensile and mode I fracture tests were performed for mechanical and piezoresistive characterizations. The addition of NC to CNTs doped epoxy resulted in a better CNT dispersion, hindering CNT re-agglomeration. A significant increase in KIC (94%) and GIC (254%) compared to the neat epoxy was obtained for the hybrid nanocomposites loaded at 1 wt% NC due to crack bridging and crack deflection. The electrical conductivity of the ternary state materials increased by 700% and 400% with respect to the binary nanocomposite, for 0.5 wt% and 1 wt% NC loadings, respectively. The hybrid nanocomposites also manifested higher piezoresistivity and a more robust signal in tensile and fracture tests, respectively. [Display omitted] •The first study on piezoresistivity performance of hybrid CNTs and nanoclay doped epoxy.•Developing a novel method using secondary nanofiller in order to thoroughly improve CNTs dispersion.•Ternary nanocomposite showed better mechanical, electrical and electromechanical properties compared to the binary one.