Frequency and Temperature Dependences of Dielectric Dispersion and Electrical Properties of Polyvinylidene Fluoride/Expanded Graphite Composites. (19th January 2010)

• Record Type: Journal Article
• Authors: Li, Yu Chao; Li, Robert Kwok Yiu; Tjong, Sie Chin
• Other Names: Mago Gaurav Academic Editor.
• Is Part Of: Journal of nanomaterials. Volume 2010(2010)
• Publication Date: 2010-01-19
• Subjects: Nanostructured materials -- Periodicals; Nanotechnology -- Periodicals; Nanomatériaux; Nanostructured materials; Nanotechnology; Nanostructures; Nanotechnology; Periodicals; Fulltext; Internet Resources; Periodicals; 620.115
• DOI: 10.1155/2010/261748
• Languages: English
• ISSNs: 1687-4110

Abstract

Abstract : A conductive nanofiller, expanded graphite (EG), was introduced into polyvinylidene fluoride (PVDF) by direct melt blending process. The electrical conductivity and dielectric properties of resulting PVDF/EG composites were investigated in a wide range of frequencies from 10 2 to 10 8 Hz. The dielectric dispersion and conductivity of the composite system exhibited a strong frequency dependence particularly in the vicinity of percolation threshold (Φ c = 6 vol%). Moreover, the dielectric permittivity tended to decrease with increasing frequency while the conductivity displayed a reverse trend. A large permittivity was found in the composite having EG content near Φ c . Accordingly, percolation concept and biased random walk approach can be used to describe the carrier transport of percolating PVDF/EG system. The conductivity and permittivity of percolating PVDF/EG composites were observed to be temperature dependent.