Core‐shell structured poly(glycidyl methacrylate)/BaTiO3 nanocomposites prepared by surface‐initiated atom transfer radical polymerization: A novel material for high energy density dielectric storage |
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Authors: | Muhammad Ejaz Venkata S Puli Ravinder Elupula Shiva Adireddy Brian C Riggs Douglas B Chrisey Scott M Grayson |
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Institution: | 1. Department of Chemistry, Tulane University, New Orleans, Louisiana;2. Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana |
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Abstract: | Core‐shell structured barium titanate‐poly(glycidyl methacrylate) (BaTiO3‐PGMA) nanocomposites were prepared by surface‐initiated atom transfer radical polymerization of GMA from the surface of BaTiO3 nanoparticles. Fourier transform infrared spectroscopy confirmed the grafting of the PGMA shell on the surface of the BaTiO3 nanoparticles cores. Transmission Electron Microscopy results revealed that BaTiO3 nanoparticles are covered by thin brushes (~20 nm) of PGMA forming a core‐shell structure and thermogravimetric analysis results showed that the grafted BaTiO3‐PGMA nanoparticles consist of ~13.7% PGMA by weight. Upon incorporating these grafted nanoparticles into 20 μm‐thick films, the resultant BaTiO3‐PGMA nanocomposites have shown an improved dielectric constant (ε = 54), a high breakdown field strength (~3 MV/cm) and high‐energy storage density ~21.51 J/cm3. AC conductivity measurements were in good agreement with Jonscher's universal power law and low leakage current behavior was observed before the electrical breakdown field of the films. Improved dielectric and electrical properties of core‐shell structured BaTiO3‐PGMA nanocomposite were attributed to good nanoparticle dispersion and enhanced interfacial polarization. Furthermore, only the surface grafted BaTiO3 yielded homogenous films that were mechanically stable. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 719–728 |
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Keywords: | core‐shell structured nanocomposites atom transfer radical polymerization barium titanate poly(glycidyl methacrylate) grafted nanoparticles dielectric properties |
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