Complex Permittivity Characteristics of Epoxy Nanocomposites at Low Frequencies

Singha, Santanu and Thomas, Joy M and Kulkarni, Ajit (2010) Complex Permittivity Characteristics of Epoxy Nanocomposites at Low Frequencies. In: IEEE Transactions on Dielectrics and Electrical Insulation, 17 (4). pp. 1249-1258.

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Abstract

The complex permittivity characteristics of epoxy nanocomposite systems were examined and an attempt has been made to understand the underlying physics governing some of the unique macroscopic dielectric behaviors. The experimental investigations were performed using two different nanocomposite systems with low filler concentrations over the frequency range of 10(-2)-400 Hz, but for some cases, the data has been reported upto 10(6) Hz for a better understanding of the behaviors. Results demonstrate that nanocomposites do possess unique permittivity behaviors as compared to those already known for unfilled polymer and microcomposite systems. The nanocomposite real permittivity and tan delta values are found to be lower than that of unfilled epoxy. In addition, results show that interfacial polarization and charge carrier mobilities are suppressed in epoxy nanocomposite systems. The complex permittivity spectra coupled with the ac conductivity characteristics with respect to frequency was found to be sufficient to identify several of the nanocomposite characteristics like the reduction in permittivity values, reduction in the interfacial polarization mechanisms and the electrical conduction behaviors. Analysis of the results are also performed using electric modulus formalisms and it has been seen that the nanocomposite dielectric behaviors at low frequencies can also be explained clearly using this formalism.

Item Type:	Journal Article
Publication:	IEEE Transactions on Dielectrics and Electrical Insulation
Publisher:	IEEE
Additional Information:	Copyright of this article belongs to IEEE.
Keywords:	Epoxy nanocomposites; nanodielectrics; permittivity; tan delta; interfacial polarization; conductivity; Cole-Cole plot; electric modulus
Department/Centre:	Division of Electrical Sciences > Electrical Engineering
Date Deposited:	29 Nov 2010 12:12
Last Modified:	02 Nov 2011 06:18
URI:	http://eprints.iisc.ac.in/id/eprint/33971

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