BaTiO₃-Filled Epoxy Resin Composites: Numerical Modelling of Dielectric Constants

Abstract

The influence of BaTiO 3 content on the composite dielectric properties was investigated by finite element method (FEM). This method is attractive because of its technological applications such as those in electromagnetic shields, since it allows to determine the dielectric constant of heterogeneous mediums and show or display the electric field into the material in order to understand the interfacial behaviours. The dielectric response of an anisotropic and periodic heterostructure, was evaluated and quantified by means of a quasistatic approximation using Laplace's equation which was solved by 3D FEM.The numerical calculations were confronted with experimental data. Measurements of the effective permittivity were carried out in samples prepared by dipping technique.

BaTiO3–Epoxy Composites for Electronic Applications

“…Although not reported in this work, as expected, the dielectric constant of BaTiO 3 -epoxy composites increases with the increase in BaTiO 3 content. 15,[17][18][19][20] Both measures, e 0 and tand, were influenced by the THF addition and frequency. Dielectric loss decreases when frequency rises, until 1 kHz due to dc conductivity effect, and after that a broad peak is observed in all the samples.…”

“…It appears that silane acts as a molecular bridge between the polymer and the ceramic filler, which improves the dielectric properties, at least at low concentrations. 17 Besides the good microstructure obtained in these composites, the presence of the coupling agent assures higher permittivity values. 27 Nevertheless, higher silane amounts tend to lower dielectric properties because of higher porosity, particle agglomeration, and defect content.…”

“…20 In this model, the FEM was used to solve the mathematical problem. 17,20,21 The boundary conditions applied were a potential difference (DV 5 U 2 ÀU 1 ) of 1 V along the z direction (Dirichlet boundary condition) and gradients of potential equal to zero (Neumman boundary condition) for the other two Cartesian directions (qu/qn x 5 0 and qu/qn y 5 0), as shown in Fig. 1B.…”

“…Thus, numerical methods, such as the finite element method (FEM) or boundary element method, seem to be very suitable approaches to describe the behavior of these materials because these methods do not impose restrictions to the geometry, to the nonlinear properties of components, or to the number of phases of the composite material. [17][18][19][20] In this paper, we review our previous works related with dielectric properties of epoxy/BaTiO 3 composites. Parts of this information have been reported before but here it is presented in a general and brief way, and related with the dielectric performance of these composites.…”

Dielectric response, functionality and energy storage in epoxy nanocomposites: Barium titanate vs exfoliated graphite nanoplatelets

“…Nowadays a lot of research is carried out in developing compact systems with integrated nanocapacitors, which could act as electrical energy storing devices [3,15e17]. The latter could be used in emerging technological applications such as cellular phones, wireless personal digital assistants, acoustic emission sensors, stationary power systems and hybrid electric vehicles [3,5,18,19].…”