Impedance Spectroscopy of Dielectrics and Electronic Conductors

Bonanos, Nikolaos; Pissis, P.; Macdonald, J. Ross

doi:10.1002/0471266965.com121

Cited by 28 publications

(22 citation statements)

References 39 publications

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“…Moreover, the dielectric permittivity depends exponentially on the carbon nanofiller content, as reported in Fig. 12b and already observed in other literature studies [63][64]. This increase of ε' in the polymer nanocomposites caused by the growing percentage of conductive particles can be attributed to the enhancement of interfacial polarization [65].…”

Section: Ac Electrical Propertiessupporting

confidence: 79%

Electrical conductivity of carbon nanofiber reinforced resins: Potentiality of Tunneling Atomic Force Microscopy (TUNA) technique

Raimondo

Guadagno

Vertuccio

et al. 2018

Composites Part B: Engineering

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Epoxy nanocomposites able to meet pressing industrial requirements in the field of structural material have been developed and characterized. Tunneling Atomic Force Microscopy (TUNA), which is able to detect ultra-low currents ranging from 80 fA to 120 pA, was used to correlate the local topography with electrical properties of tetraglycidyl methylene dianiline (TGMDA) epoxy nanocomposites at low concentration of carbon nanofibers (CNFs) ranging from 0.05% up to 2% by wt. The results show the unique capability of TUNA technique in identifying conductive pathways in CNF/resins even without modifying the morphology with usual treatments employed to create electrical contacts to the ground.Epoxy matrix-based composite materials filled with MWCNTs or various carbon additives, such as natural, artificial and exfoliated graphites (EGs), activated carbons, and thick graphene exhibit many properties of great interest both from a scientific and industrial point of view such as low electrical percolation threshold (below 1.5 wt.%) as well as high electromagnetic interference (EMI) shielding capacity, good adhesive properties etc… [1].CNF-reinforced polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanofibers play a promising role due to their potential applications in order to improve mechanical, electrical, thermal performance and relative ease of processing in composites used in the aerospace field [2][3][4][5][6][7]. Moreover, in high performance resin formulations, CNFs can be used as effective low-cost replacements for carbon nanotubes (CNTs) since the cost of CNFs is much lower than that of CNTs while possessing similar physical properties. The tetrafunctional epoxy resin tetraglycidyl methylene dianiline (TGMDA) cured with the aromatic diamine 4,4'-diaminodiphenylsulfone (DDS) is one of the most widely employed matrices for the production of high performance fiber composites in the aircraft and spacecraft industries [8]. Carbon nanofibers with extremely high aspect ratios combined with low density possess high electrical conductivity. They are excellent nanofiller materials for transforming electrically non-conducting polymers into conductive materials which have a wide range of applications, namely in electromagnetic interference (EMI) shielding (which has become a critical issue in the last several years with the development and advancement of electrical devices), photovoltaic devices, transparent conductive coatings as well as electro-actuating the shape memory polymer composites [9][10][11][12][13][14][15][16][17][18] and others [19][20][21]. Therefore, they are highly sought-after candidate materials to replace traditional metallic materials for lightning strike protection of aircrafts. Modern aircrafts are made of advanced composite materials, which are significantly less conductive than aluminum. Lightning is initiated at the airplane's leading edges, which ionize, creating a strike opportunity. Lightning currents travel along the airplane and exit to the ...

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Section: Ac Electrical Propertiessupporting

confidence: 79%

Electrical conductivity of carbon nanofiber reinforced resins: Potentiality of Tunneling Atomic Force Microscopy (TUNA) technique

Raimondo

Guadagno

Vertuccio

et al. 2018

Composites Part B: Engineering

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“…The Nyquist plots (imaginary part vs. real part of the complex impedance) exhibit depressed arcs that can be modeled by a circuit equivalent of a resistor and a parallel constant phase element (CPE), as indicated in the figure. From the resistance R, the conductivity is calculated by

where d is the average nonwoven thickness and A is the cross-sectional area, corresponding to the contact area between the electrodes and the sample [ 94 ]. All three samples exhibit only negligible conductivity ( Table 1 ), which indicates that the low carbonization temperature of 500 °C does not lead to sufficient formation of conducting percolation paths along the CNFs.…”

Section: Resultsmentioning

confidence: 99%

“…where d is the average nonwoven thickness and A is the cross-sectional area, corresponding to the contact area between the electrodes and the sample [94]. All three samples exhibit only negligible conductivity (Table 1), which indicates that the low carbonization temperature of 500 • C does not lead to sufficient formation of conducting percolation paths along the CNFs.…”

Section: Electrical Propertiesmentioning

confidence: 99%

Chemical and Morphological Transition of Poly(acrylonitrile)/Poly(vinylidene Fluoride) Blend Nanofibers during Oxidative Stabilization and Incipient Carbonization

et al. 2020

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Thermally stabilized and subsequently carbonized nanofibers are a promising material for many technical applications in fields such as tissue engineering or energy storage. They can be obtained from a variety of different polymer precursors via electrospinning. While some methods have been tested for post-carbonization doping of nanofibers with the desired ingredients, very little is known about carbonization of blend nanofibers from two or more polymeric precursors. In this paper, we report on the preparation, thermal treatment and resulting properties of poly(acrylonitrile) (PAN)/poly(vinylidene fluoride) (PVDF) blend nanofibers produced by wire-based electrospinning of binary polymer solutions. Using a wide variety of spectroscopic, microscopic and thermal characterization methods, the chemical and morphological transition during oxidative stabilization (280 °C) and incipient carbonization (500 °C) was thoroughly investigated. Both PAN and PVDF precursor polymers were detected and analyzed qualitatively and quantitatively during all stages of thermal treatment. Compared to pure PAN nanofibers, the blend nanofibers showed increased fiber diameters, strong reduction of undesired morphological changes during oxidative stabilization and increased conductivity after carbonization.

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“…LECTROCHEMICAL impedance spectroscopy (EIS) [1,2] is the extremely powerful technique for characterization of either different electrode materials toward their electrical/dielectrical, [3] electrocatalytic [4] and corrosive properties, [5] or different electrochemical devices such as energy conversion/storage devices [6] or electrochemical sensors. [7] Impedance measurements are based on measuring the electrical response to some small periodic electrical excitation of the system.…”

Section: Introductionmentioning

confidence: 99%

Frequency Response Analysis of a Nonstationary System: Electrochemical Transition of Polyaniline

Košiček¹,

Horvat-Radošević²,

Kvastek³

2018

Croat. Chem. Acta

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In this work, impedance spectra of polyaniline film electrode recorded at some redox transition potentials have been corrected for nonstationarity by application of Stoynov's 4-D method. The procedure consisted from: a) conventional measurements of a series of impedance spectra under strictly same experimental conditions, which are accompanied by monitoring of real operating time intervals for measurement of each particular impedance spectrum of the series, b) determination of functional dependence(s) between iso-frequency impedance values and operating time, and c) calculations of instantaneous IS for the time instant of the beginning of the first IS measurement. Comparison between measured and instantaneous impedance spectra, and also between their individual impedance parameter values pointed toward significant differences in charge transfer and transport resistance values. The results suggest that erroneous (either underestimated or overestimated) charge transfer and transport resistance values will be obtained if measured impedance spectra were not corrected for nonstationarity.

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Impedance Spectroscopy of Dielectrics and Electronic Conductors

Cited by 28 publications

References 39 publications

Electrical conductivity of carbon nanofiber reinforced resins: Potentiality of Tunneling Atomic Force Microscopy (TUNA) technique

Electrical conductivity of carbon nanofiber reinforced resins: Potentiality of Tunneling Atomic Force Microscopy (TUNA) technique

Chemical and Morphological Transition of Poly(acrylonitrile)/Poly(vinylidene Fluoride) Blend Nanofibers during Oxidative Stabilization and Incipient Carbonization

Frequency Response Analysis of a Nonstationary System: Electrochemical Transition of Polyaniline

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