Enhanced dielectric constant of polymer-matrix composites using nano-BaTiO3 agglomerates

Abstract

The epoxy/matrix composites incorporating with dispersed and agglomerated nano-BaTiO3 fillers were investigated. The relative dielectric constants of the composites with the agglomerated particles were significantly improved, compared to those of the composites with the well-dispersed particles. In addition, the experimental data were in better agreement with the values calculated by the Lichteneker's model than with those of the conventional Maxwell-Garnett's model which has been widely employed for the calculation of the dielectric constant of polymer/filler composites. In order to promote an agglomeration by interlocking between the nanoparticles, the BaTiO3 powders were heat-treated at various temperatures. An epoxy composite with 40 vol% BaTiO3 heat-treated at 800°C for 1 h exhibited an excellent relative dielectric constant of 67, along with high polarizability, low dielectric loss, and low leakage current. Similarly, the epoxy composites with agglomerated SrTiO3 fillers provided a higher dielectric constant than that of their dispersed counterparts. The origin of the increase in the relative dielectric constant achieved by the agglomeration effect is also suggested.

One-Step Solvent Evaporation-Assisted 3D Printing of Piezoelectric PVDF Nanocomposite Structures

“…58 Hence, the increased presence of β-phase in PVDF upon the addition of 10 wt.% NPs via ball-milling is attributed to the mechanical activation of the NPs and their dispersed agglomerates, leading to an increased dipole moment. 26,48 Further, given that the piezoelectric coefficients of the filler and the polymer have different signs, poling in a single direction would cancel out the d31 coefficients. 59 Hence, our approach to orient dipoles without the application of any electric field serves to improve the inherent piezoelectric properties in PVDF at low mass fraction.…”

“…Addition of ecofriendly and biocompatible , piezoelectric ceramic filler barium-titanate (BaTiO 3 NPs) − into PVDF has also shown to improve the ferro- and piezoelectric properties of PVDF without compromising its flexibility or strength. The incorporation of BaTiO 3 NPs into PVDF has been attempted so far via sonication ,, and ball-milling , approaches.…”

Design and application of piezoelectric biomaterials

“…The enhanced performance of the sensor was due to the improvement of inherent piezo electric prop erties of the PVDF film. The 10 wt.% BaTiO 3 piezoelectric fillers added in PVDF play the role of mechanical activation for the increase of dipole moments [74,75].…”

Ultrasonication optimisation and microstructural characterisation for 3D nanoparticle dispersion in thermoplastic and thermosetting polymers

“…As benchmarking systems, both a thermoset and thermoplastic matrix are selected as commonly used types of polymer matrices. First, BaTiO 3 is a polar ferroelectric particle often used as a fiducial marker for DVC or in dielectrics for capacitors [12,24,39,[41][42][43]. A strong agglomeration of BaTiO 3 has been observed in epoxy and needs to be resolved to not influence the final matrix properties [43].…”