Impedance spectroscopy study of polyester/carbon nanotube composites

Abstract

The electrical properties of carbon nanotubes loaded in polyester polymer matrix were studied by using the impedance spectroscopy technique. The study was carried out in the frequency range between 100 Hz and 1 MHz and temperature between 170 and 400 K. Cole–Cole representation was used to interpret the impedance spectra of all the samples. The variation of the electrical conductivity, as a function of temperature, for concentrations higher than the conduction threshold was analyzed. This variation undergoes a significant decrease from a critical temperature that corresponds to the phenomenon known as positive temperature coefficient in resistivity. Tunneling effect is responsible for the change of the conductivity. The carbon particles are not in physical contact and the electrons tunnel through the insulating polymer gap between particles. With the rise of temperature, the gap between particles increases and tunneling becomes less probable. Consequently, above this temperature, the electrical conductivity begins to increase, due to the fact that the temperature dependence of conductivity is mainly related with different thermal expansion of polymer matrix and carbon nanotubes. POLYM. COMPOS., 39:1297–1302, 2018. © 2016 Society of Plastics Engineers

Self‐Healing and Electrical Properties of Viscoelastic Polymer–Carbon Blends

“…The Nyquist plot of EIS results shows only one semicircle, which we attribute to the tunneling conductivity of materials. The tunneling current ceases to dominate at these voltage values, [ 38 ] and electrical breakdowns between separated CB particles and aggregates occur. Therefore, for the application of the composite, where high conductivity is required, a voltage higher than ≈2 V should be used to prevent the impact of nonlinear tunneling current.…”

Reduced Graphene Oxide Coated Silk Fabrics with Conductive Property for Wearable Electronic Textiles Application

“…Thus, great efforts have been dedicated to fabricating wearable electronic textiles using carbon nanotubes, carbon nanofibers, graphene‐based materials, or hybrids of them. Among them, some studies on wearable electronic textiles fabricated by traditional textiles like cotton, nylon‐6, polyester, and silk fabrics coated with graphene oxide (GO) by using bovine serum albumin (BSA) as glue have been reported. Yun et al reported a new e‐textile produced by RGO/nylon‐6 textiles by using BSA as a glue.…”

In Situ Direct Laser Writing of 3D Graphene‐Laden Microstructures

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“…In addition to being a useful method of characterizing the electrical performance of composite materials, [ 31 ] impedance spectroscopy is a common technique used in microfluidic devices with integrated microelectronics designed for biological analysis such as cell or bacterial detection, [ 32 ] particle detection, [ 33 ] and chemical sensing. [ 34 ] To investigate the AC performance of the microstructures fabricated with the developed photocomposite, an 8‐turn microcoil printed between two patterned ITO contact pads was printed (Movie S3, Supporting Information), with an rGO particle loading of 1 wt%.…”