Resistance sensing response optimization and interval loading continuity of multiwalled carbon nanotube/natural rubber composites: Experiment and simulation

Abstract

To achieve long-term and real-time monitoring of the deformation of isolation bearings, a conductive composite with a natural rubber (NR) matrix modified by multiwalled carbon nanotubes (MWCNTs) is processed by prestrain. The resistance-strain response of this composite indicates excellent uniformity, linearity, hysteresis, reproducibility and stability due to the prestrain process for the composite before application. To explain the mechanism of the resistance-strain response for the composite, a theoretical model is developed to analyze the relation between the conductivity and the MWCNT network structure. Mechanical and electrical testing under cyclic loads indicates that the prestrain of the composite could reduce or even eliminate the 'shoulder peak' effect of the resistance-strain curve. Meanwhile, the resistance-strain response behavior is independent of the prestrain temperature and discontinuous before and after the interval time. Furthermore, the coarse-grained molecular dynamics simulation and microstructure testing indicate that the resistance-strain response is induced by the changing orientation of MWCNT molecules in the rubber matrix under tension loading. All of the results and findings provide potential applications of this MWCNT/NR composite for deformation monitoring.

Modeling and Optimization of the Creep Behavior of Multicomponent Copolymer Nanocomposites

“…The tunnel effect theory is a conductivity theory based on the microscopic investigation of composite conductive polymer materials; according to the theory, the resistance of composite conductive polymer materials can be stated as [ 29 , 30 ]: where R represents the resistance of the sensing unit, L represents the number of particles on a single effective conducting path, N represents the number of effective conducting paths in the sensing unit, h represents Planck’s constant, e represents the electron charge, s represents the minimum distance between particles in the sensing unit, a 2 represents the effective cross-sectional area between two particles, m represents the electron mass and represents the potential barrier height.…”

The Effect of Filler Dimensionality and Content on Resistive Viscoelasticity of Conductive Polymer Composites for Soft Strain Sensors

“…Maintaining a high sensitivity of CPCs during cyclic stretching and relaxation is as important as obtaining high initial sensitivity. As shown in Figure 9 a,b, we introduced the relative resistance R / R 0 peak of the first cycle (P), the decrease of peak value during cyclic strains (D), and the change amplitude (A) of R / R 0 for CPCs to evaluate the decline of sensitivity [ 17 , 46 ]. The D/P represents the attenuation ratio, A/P describes the maintenance of sensitivity, and the increase in D/P and the decrease in A/P both represent the decline of sensitivity during cycling.…”

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

“…It is possible to combine the good qualities and synergistic effects of CPCs by doping them with nanofillers in a polymer matrix. As such, the choice of conductive nanofillers and matrix materials has a significant impact on the composites' performance [6].…”