Effect of high aspect ratio filler on dielectric properties of polymer composites: A study on barium titanate fibers and graphene platelets
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Authors
Wang, Zepu
Nelson, J. Keith
Miao, Jianjun
Linhardt, Robert J.
Schadler, Linda S.
Hillborg, Henrik
Zhao, Su
Issue Date
2012-06-01
Type
Article
Language
ENG
Keywords
Biology , Chemistry and chemical biology , Chemical and biological engineering , Biomedical engineering
Alternative Title
Abstract
High aspect ratio fillers are predicted to increase the dielectric constant of polymer composites more efficiently than spherical fillers according to the rule of mixtures. Using high aspect ratio fillers is a promising route for creating high dielectric constant, low loss materials at a low filler volume fraction, for use as capacitor and electric field grading materials. In this work, two high aspect ratio fillers were mixed into a polymer matrix, and the dielectric properties of composites were studied. Barium titanate fibers were synthesized by electrospinning a sol-gel, followed by a heat treatment to obtain a perovskite crystal structure. The heat treatment conditions were found to be crucial for obtaining tetragonal barium titanate fibers with high dielectric constant. Graphene platelets were prepared by a thermal shock method, which was found to result in a larger dielectric constant. A combination of barium titanate and graphene platelets yielded the highest dielectric constant when used in a polydimethyl siloxane matrix. The increase in dielectric loss over the pure matrix was small when the volume fraction was below the percolation threshold of graphene platelets. Electric flux density-electric field (D-E) measurements showed a linear dielectric constant in barium titanate filled composites and higher loss when graphene was added. The ac breakdown strength was reduced compared to the neat polymer and was affected by filler aspect ratio. The mechanisms that lead to the observed phenomena are discussed.
Description
IEEE Transactions on Dielectrics and Electrical Insulation, 19, 960-967
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Full Citation
Effect of high aspect ratio filler on dielectric properties of polymer composites: A study on barium titanate fibers and graphene platelets, Z. Wang, J. K. Nelson, J. Miao, R.J. Linhardt, L. S. Schadler, H. Hillborg, S. Zhao, IEEE Transactions on Dielectrics and Electrical Insulation, 19, 960-967, 2012.
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DOI
ISSN
10709878