Effect of TiO₂on enhanced pyroelectric activity of PVDF composite

Abstract

Thin films of a ferroelectric polymer matrix made of poly(vinylidene fluoride) (PVDF) incorporated with a non-ferroelectric inclusion, TiO2, were prepared with different volume fractions (0–30 wt%). The dielectric and pyroelectric properties of the PVDF/TiO2 composite thin films are revealed as a function of different annealing temperatures (60 to 140 °C). Theoretical models, including Maxwell, Clausius–Mossotti, Furukawa and effective medium theory models were employed to describe the effective dielectric permittivity of the composites. This report also studies the effect of a non-ferroelectric inclusion, which contributed to the enhancement of pyroelectric activity after the poling process, in a ferroelectric polymer matrix based composite. An increase in the dc conductivity of the polymer matrix led to an easier poling process and reduced the required poling electric field from 260 to 120 MV m−1. The pyroelectric coefficient of the polymer composite has been enhanced at a much lower poling electric field. The surface and structural properties of the thin film composites were also characterized by scanning electron micrographs, Fourier transform infrared spectroscopy and x-ray diffractometry.

Enhancing pyroelectric and ferroelectric properties of PVDF composite thin films by dispersing a non-ferroelectric inclusion La2O3 for application in sensors

“…It reached about 42 lC/m 2 K, 40% higher than that of pure PVDF. As mentioned in our previous work, the increase in annealing temperature from 60°C to 140°C improved the crystallinity of the films, as indicated by the formation of the spherulite structure and the diffusion of the pin-holes [9]. The poor pyroelectric performance of annealing temperatures below 100°C was owed to the pin-hole effect, which reduced the effective poling electric field.…”

“…e l s e v i e r . c o m / l o c a t e / o r g e l activity in the composite [9,10]. Continuing this work, we introduced non-ferroelectric inclusion of La 2 O 3 with low volume fraction into a polymer matrix of Form II PVDF to form a two-phase composite system.…”

Hot Plate Annealing at a Low Temperature of a Thin Ferroelectric P(VDF-TrFE) Film with an Improved Crystalline Structure for Sensors and Actuators

“…The static (zero-frequency) pyroelectric coefficient, p , was obtained by measuring the induced pyroelectric current I p during the heating of the sample from 26 to 28 °C at a nearly constant heating rate $\frac{dT}{dt}$ (2–3 °C/s) with an effective area of 1 mm 2 for all samples. The relationship of the pyroelectric coefficient is given by [21–24]. $p=\frac{I_p}{A\left(\frac{dT}{dt}\right)}$…”

Advances in Piezoelectric Polymer Composites for Energy Harvesting Applications: A Systematic Review

“…Mechanical behavior of as‐prepared 2 wt% PVDF/iron oxide composites indicated a significant improvement in the storage modulus and enhancement in the thermal stability about 28 °C as compared to that of PVDF. Gan et al., in the same year, prepared a PVDF composite by using TiO 2 nanoparticles with different volume fractions (0–30 wt%) and reported an increase DC conductivity, leading to an easier poling process requiring less electric field (from 260 to 120 MV m −1 ).…”