Effect of conductivity transportation from carbon nanotubes (CNT) to polymer matrix surrounding CNT on the electrical conductivity of nanocomposites

Abstract

In this article, the interphase thickness in polymer carbon nanotubes (CNTs) nanocomposites (PCNT) is correlated to CNT radius and the extent of conductivity transportation from CNT to polymer matrix surrounding the CNT (K). In addition, CNT properties and “K” are applied to suggest the simple equations for percolation threshold and the fraction of networked CNT. A simple model is developed to predict the conductivity of PCNT assuming CNT size, “K” and tunneling resistance. The impacts of different parameters on the interphase thickness, percolation threshold, the fraction of networked CNT, and the conductivity of nanocomposites are studied and many experimental results are used to confirm the predictions. Thin and large CNT as well as high “K” cause low percolation threshold, large conductive networks and desirable conductivity in nanocomposites. Moreover, high tunneling resistivity and large tunneling distance negatively affect the conductivity, but the exceptional CNT conductivity is ineffective. The reasonable roles of all parameters in the predicted conductivity and the fine agreement between predictions and experimental results confirm the developed model.

Highly Sensitive Flexible Sensors for Human Activity Monitoring and Personal Healthcare

“…Herein, we proposed a solid self-assemble strategy to prepare a stretchable and conductive MWCNT/GNFs@PDMS nanomaterials sensor by transferring graphene nanosheets (GNFs) films onto a interleaved carboxylated MWCNT layer on polydimethylsiloxane (PDMS) conductive substrate through electrostatic adsorption. , The van der Waals force endows the inner carbon tube with strong robustness without breaking. The network bridge structure allows the transmission of electrons in the microscopic state in the form of tunneling effect in which the tunneling effect can still be achieved even though the connection of carbon nanotubes is broken due to high tensile strength, so as to ensure the relatively stable conductivity of the film . In addition, due to the form of a dense conductive network, GNFs integrate with MWCNT, which ensures the conductive continuity during the strain process of the device.…”

“…The network bridge structure allows the transmission of electrons in the microscopic state in the form of tunneling effect in which the tunneling effect can still be achieved even though the connection of carbon nanotubes is broken due to high tensile strength, so as to ensure the relatively stable conductivity of the film. 49 In addition, due to the form of a dense conductive network, GNFs integrate with MWCNT, which ensures the conductive continuity during the strain process of the device. This study aims to achieve further innovation in material and device structure, improve and optimize the sensing performance of conductive materials, and enable the production of large area and low-cost flexible sensors.…”

A 3D viscoelastic–viscoplastic behavior of carbon nanotube‐reinforced polymers: Constitutive model and experimental characterization

“…Nowadays, carbon nanotube (CNT)‐based polymer nanocomposites have become one of the most vibrant research areas in the development of nanotechnology. Low density (1.8–2 gr/cm 3 ), excellent mechanical properties (0.5–1 TPa), high yield strength (20–100 GPa), very good thermal and electrical conductivity (10 13 A/cm 2 ), and high aspect ratios of CNTs, have significantly improved the mechanical and physical properties of the resulting nanocomposites 1–10 . By adding only one percent of CNT to epoxy resin, 12%, 64%, and 39% increase in modulus, tensile strength, and fracture toughness have been achieved, respectively, compared to pure epoxy 10 .…”

Modeling of the piezoresistive behavior of carbon nanotube/polymer composites during stress relaxation

“…[5][6][7][8][9][10][11][12][13][14][15][16][17] The tunneling effect, which refers to electron hopping through an insulating polymer matrix between CNTs, is the main mechanism underlying the electrical conductivity of CNT composites. [18][19][20] Resistance change during deformation can be explained by changes in tunneling resistance. Studies have established that changes in the distance between CNTs due to deformation of the composite affects the overall resistance thereof.…”