Polyethersulfone-expanded graphite nanocomposites: charge transport and impedance characteristics

TitlePolyethersulfone-expanded graphite nanocomposites: charge transport and impedance characteristics
Publication TypeJournal Article
Year of Publication2010
AuthorsRamanujam, BTS, Mahale, RY, Radhakrishnan, S
JournalComposites Science and Technology
Date PublishedNOV0
KeywordsDifferential scanning calorimetry (DSC), Electrical properties, Modeling, Polymers, Scanning/transmission electron microscopy (STEM)

Polyethersulfone (PES)-expanded graphite nanocomposites have been prepared by solution blending route after sonicating expanded graphite in dichloromethane. It has been observed that ultrasonication results in nanosheets formation leading to a low percolation threshold of 3 wt.%. At 5 wt.% filler loading the conductivity is of the order of 10(-2) S/cm. Hopping type of charge transport occurs at 3.2 wt.% expanded graphite in PES below which capacitive effects couple. The effective dielectric constant at low frequency increases with filler concentration. Impedance measurement has been carried out to evaluate interfacial capacitance which, for 3.2 wt.% expanded graphite addition in PES, increases to 110 pF from 32 pF for 1 wt.% expanded graphite in the polymer. DSC analysis shows an increment of 12 C in the T(g) of PES with 3 wt.% expanded graphite suggesting interaction between the polymer and filler. (C) 2010 Elsevier Ltd. All rights reserved.

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Polymer Science & Engineering