One approach to increasing capacitive energy storage is to study dielectrics composed of nanoparticles in a polymer matrix.1 Recently, several of the authors have presented results for nanodielectrics composed of poly(ether imide) (PEI) and nano-sized BaTiO3.2 This includes dielectric breakdown and audio frequency relative permittivity and loss studies (carried out from 5.5K to 400K), thermal measurements and electron microscopy (scanning and transmission) for a wide range of nanoparticle concentrations. The room temperature relative permittivity vs. nanoparticle content follows a recently proposed modified Hanai equation. A relaxation in the region of 20K was found and shown to be associated with the BaTiO3 nanoparticles, themselves, and gives insight into a long-standing discussion on bonding in perovskite-type ferroelectrics. In addition, a water-associated relaxation is found in the vicinity of 200K. Finally, the dielectric breakdown strength was found to decrease as the nanoparticle content increases. Microstructure-level simulations showed that matrix field intensification cannot account for all of the variation of breakdown strength with nanoparticle concentration. Detailed studies have also been reported for BaTiO3 nanoparticles in a cavity.3 In that case, the shape and intensity of the low temperature relaxation exhibited size effects. Results for BaTiO3nanoparticles in polycarbonate are discussed and compared with those for nanoparticles in PEI.Reference s  :  1. J. K. Nelson (ed), Dielectric Polymer Nanocomposites, 2010, (New York: Springer).2. J. F. Lomax, E. A. Lomax, S. C-L. Lu, L. Haverhals, J. P. Calame, J. J. Fontanella, C. A. Edmondson, M. C. Wintersgill, M. A. Westgate, J., Smart Mater. Struct., 2012, 21 (8) : 085017-1-9.3. J. F. Lomax, J. J. Fontanella, C. A. Edmondson, M. C. Wintersgill, M. A. Westgate, S. Eker, J. Phys. Chem. C, 2012, 116 (44)  , 23742-23748.

Poly(ether imide) and polycarbonate containing barium titanate nanoparticles

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.