title: Multifunctional properties of cyanate ester composites with SiO2 coated Fe3O4 fillers.
abstract: SiO2 coated Fe3O4 submicrometer spherical particles (a conducting core/insulating shell configuration) are fabricated using a hydrothermal method and are loaded at 10 and 20 vol % into a bisphenol E cyanate ester matrix for synthesis of multifunctional composites. The dielectric constant of the resulting composites is found to be enhanced over a wide frequency and temperature range while the low dielectric loss tangent of the neat cyanate ester polymer is largely preserved up to 160 °C due to the insulating SiO2 coating on individual conductive Fe3O4 submicrometer spheres. These composites also demonstrate high dielectric breakdown strengths at room temperature. Dynamic mechanical analysis indicates that the storage modulus of the composite with a 20 vol % filler loading is twice as high as that of neat resin, but the glass transition temperature considerably decreases with increasing filler content. Magnetic measurements reveal a large saturation magnetization and negligibly low coercivity and remanent magnetization in these composites.
authors: Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors: Weixing
authors: W
authors: Sun
authors: Wuzhu
authors: W
authors: Sun
authors: Michael R
authors: MR
authors: Kessler
authors: Nicola
authors: N
authors: Bowler
authors: Kevin W
authors: KW
authors: Dennis
authors: R William
authors: RW
authors: McCallum
authors: Qi
authors: Q
authors: Li
authors: Xiaoli
authors: X
authors: Tan