Resistance-strain sensitive rubber composites filled by multiwalled carbon nanotubes for structuraldeformation monitoring

Abstract

In this article, multiwalled carbon nanotube/natural rubber composites with resistance-strain sensitivity were prepared by solution method, when the electrical percolation threshold of multiwalled carbon nanotube is only ∼3.5 wt%. The mechanical properties and resistance-strain response sensitivity were studied and analyzed systematically. The dispersion of multiwalled carbon nanotubes in the natural rubber matrix was characterized by field-emission scanning electron microscope and X-ray diffractometer. The composite exhibits good deformation sensitivity (gauge factor >27), large strain sensing range (>200%), and high signal stability when multiwalled carbon nanotube content was appropriate. The composite is suited to application in strain monitoring of large deformation structures since the resistance-strain response is more stable when strain exceeds 100%. To understand the mechanism of the resistance-strain response, the ‘shoulder peak’ of resistance-strain curve was researched and explained by the digital image correlation method, and an analytical model was developed when considering the effects of electronic tunneling and hopping in multiwalled carbon nanotube networks. Both experiment and analytical results confirm the break-restructure process of multiwalled carbon nanotube networks under applied strain cause the resistance-strain response. Finally, the practical application of the composite to monitoring strain load of rubber isolation bearing was realized.

The Effect of the Co−Blending Process on the Sensing Characteristics of Conductive Chloroprene Rubber/Natural Rubber Composites

“…This behavior is due to the rupture of the interface between the MWCNTs and the matrix during the first few cycling stages that formed new conductive paths [32], which resulted in a decrease in the resistance of the composite. After several cycles, the competition between the breakdown and formation of the conductive network was gradually balanced, and the resistance eventually stabilized [33]. Under cyclic loading, the MWCNT/CR−NR composites possessed high repeatability of the resistance-strain response and strain monitoring potential.…”

“…"Shoulder peaks" were also detected in CR-6CNT/NR, CR-3CNT/NR-3CNT, and CR/NR-6CNT composites, as described in many publications. The competition between the breakdown and repair of the conductive network under cyclic stress, as well as the viscoelasticity of the substrate, are the primary causes of the "shoulder" phenomena [33]. Furthermore, by comparing the magnitude of the ∆R/R 0 values of the composites with different blending processes, the CR-6CNT/NR composite had the greatest amplitude of resistance change, indicating that it had the greatest resistance-strain response sensitivity, which was consistent with the phenomenon observed in Figure 6.…”

The role of CNT in surface defect passivation and UV emission intensification of ZnO nanoparticles

“…30 Furthermore, combining CNT with rubber increases the resistance-strain response of the composite. 31 CNT are produced by several different synthesis routes such as chemical vapour deposition, electric arc discharge and laser ablation. 32 Due to their inertness, functionalizing CNT, that is, attaching functional organic moieties to the walls of the CNT is a prerequisite to combining them with other organic and inorganic materials.…”

Carbon nanotubes, nanorings, and nanospheres: Synthesis and fabrication via chemical vapor deposition—a review

“…Since Iijima. (1991) 3 found CNTs accidentally while synthesizing fullerene by arc discharge method, undoubtfully it became the headlines of nanotechnology due to their unique mechanical, 4,5 thermal, and electrical properties. 6,7 Recently, toroidal CNTs catch the attention of researchers because they can be used directly as a nanoscale device.…”