Dielectric properties estimation of nanodielectric interphase by numerical modeling and dielectric spectroscopy

This paper proposes a method to estimate the frequency dependent dielectric properties of the interphase which exists in nanodielectrics that consist of polypropylene filled with nanoparticles of SiO
₂
. This method is based on a 3D electroquasistatic numerical model, built by considering the nanocomposite subdomains (polymer matrix, nanoparticles and interphase) as dispersive materials. The frequency dependent properties of the polymer matrix are obtained from dielectric spectroscopy. The frequency dependent dielectric properties of the interphase are obtained by using semi-analytic formulas (linear mixture and Bruggeman) corrected if necessary by means of an optimization procedure. The numerical results in the frequency range of 10
^-2
- 10
⁶
Hz are close to the experimental ones, which proves that this approach can be useful to estimate the properties of the nanodielectric interphase.