**2. Experimental procedure**

**1. Introduction**

74 Ferroelectrics and Their Applications

roelectric particles, i.e., BaTiO3

for capacitors, transistors, and actuators.

with different percentages of BaTiO<sup>3</sup>

constituents.

matrix.

frequencies [8].

Biopolymers have attained significant market potential due to their numerous applications in diverse fields such as "bio-ceramic, bio-sensing, bio-encapsulation, and bio-inorganic nanoparticles" [1]. The main motivation for studying these biopolymers rises from their unique characteristics: bio-compatibility, low environmental impact, and nontoxicity (for human use) [2, 3]. Since these materials are biodegradable, they can be recycled, which translates into waste reduction and smaller recycling cost. An additional appealing feature is the low fabrication cost of these biopolymers when compared to petroleum-based ones.

Researchers have been using these biopolymers as matrices for composites containing fer-

seeking for an alternative for processable high permittivity materials with high dielectric constant, moderate dielectric strength, low dielectric loss, high electrical resistivity, among other properties [4, 5]. These electrical characteristics made these composites particularly suitable

For instance, Neagu et al. studied dielectric properties of bio-composites made of chitosan

tion methods available to produce the polymeric films, the authors selected the dry phase

the polymeric matrix raised the dielectric constant while lowering the dielectric loss. This led to a simple approach to create flexible electronic devices made of polymeric and ferroelectric

Moreover, Elimat evaluated the electrical properties of composites made of epoxy with various zinc oxide (ZnO) concentrations and reinforced with 1.0 wt% of conductive carbon black nanoparticles to dissipate any potential electrostatic charges [7]. The results revealed an increase in higher dielectric constant values as the temperature and the ZnO concentration heightened. However, that dielectric constant diminished for higher frequencies, namely from 0.1 to 1 MHz; this was attributed to the dipoles' lack of time to align with the electrical field. In addition, the authors demonstrated that higher concentrations of ZnO nanoparticles increased the electrical conductivity of the composites. Such higher electrical conductivity is due to the increase of the charge carriers' density in the polymeric

Petrov et al. studied the electrical properties of chitosan and hydroxyapatite (HA) biocomposites. In their study, they implemented an innovative approach via a corona discharge treatment to increase the charge surface of the polymeric matrix. The researchers tested the dielectric permittivity of the composites using dielectric spectroscopy and by employing a parallel plate capacitor for the electrical measurements. Their results evinced no difference in dielectric permittivity between the composites made of 6 and 10 g/L of chitosan solution. However, a notable difference was observed in the dielectric permittivity as a function of temperature and frequency. Although higher temperatures increased the dielectric permittivity of the composites, such permittivity decreased at higher

, and PbTiO3

particles: 0, 1 and 10% [6]. Among the different fabrica-

. In particular, they have been

concentrations in

, CaTiO3

, SrTiO3

inversion casting process. This research demonstrated that higher BaTiO3

The present research encompassed two stages. In the first one, the composites were synthesized to produce enough material for the second stage. Upon this stage, the composites underwent both mechanical and electrical characterization. This experimental section was completed in the facilities of the Nanotechnology Center hosted by the University of Puerto Rico – Mayagüez, from August 2013 to August 2015.
