Large enhanced dielectric permittivity in polyaniline passivated core-shell nano magnetic iron oxide by plasma polymerization

Abstract

Commercial samples of Magnetite with size ranging from 25–30 nm were coated with polyaniline by using radio frequency plasma polymerization to achieve a core shell structure of magnetic nanoparticle (core)–Polyaniline (shell). High resolution transmission electron microscopy images confirm the core shell architecture of polyaniline coated iron oxide. The dielectric properties of the material were studied before and after plasma treatment. The polymer coated magnetite particles exhibited a large dielectric permittivity with respect to uncoated samples. The dielectric behavior was modeled using a Maxwell–Wagner capacitor model. A plausible mechanism for the enhancement of dielectric permittivity is proposed.

Polymer bilayers with enhanced dielectric permittivity and low dielectric losses by Maxwell–Wagner–Sillars interfacial polarization: Characteristic frequencies and scaling laws

“…Therefore, the toughest difficulty in designing a percolative dielectric material is to enhance its permittivity but maintain the dielectric loss as low as possible. In most cases, accompanied with enormous enhancement of dielectric permittivity, the formation of numerous local conductive paths brings about undesired leakage current causing a quite high dielectric loss, which greatly limits the future applications in charge storage field …”

Extreme enhancement and reduction of the dielectric response of polymer nanoparticulate composites via interphasial charges

“…Extreme enhancement and reduction of the dielectric response of polymer nanoparticulate composites via interphasial charges Over the past ten years, a host of experiments [1][2][3][4][5][6][7] have shown that the macroscopic (i.e., homogenized) permittivity of polymers filled with nanoparticles can be drastically different-higher or lower-from that of the same polymers unfilled or filled with microparticles. Motivated by prior work on suspensions of particles in electrolytic solutions, 8,9 in this Letter, we show theoretically how such "anomalous" behavior can be described and explained by the presence of interphasial charges.…”

“…It is straightforward to verify that the electric potential (7) satisfies identically the Poisson's equation (5). The jump conditions (6) entail that…”

Fe3O4@polyaniline yolk-shell micro/nanospheres as bifunctional materials for lithium storage and electromagnetic wave absorption

“…The relative complex permittivity (εr, εr=ε'-jε'', ε' and ε'' are the real and imaginary parts) and permeability (μr, μr=μ'-jμ'', μ' and μ'' are the real and imaginary parts) were determined from S-parameters taking advantage of the simulation program of the Reflection/Transmission Nicolson-Ross model [54]. The reflection loss was calculated by the following equation [42][43][44][45][46][47]:…”

“…Although different kinds of Fe3O4 and PANI composites have been synthesized by employing a wide range of polymerization routes or self-assembly methods [42][43][44][45][46], less attention has been paid to study the lithium storage properties of Fe3O4/PANI composite anodes.…”