Dielectric and piezoelectric properties of lead free BZT-BCT/PVDF flexible composites for electronic applications

Dielectric, electric, and piezoelectric properties of three‐phase piezoelectric composite based on castor‐oil polyurethane, lead zirconate titanate particles and multiwall carbon nanotubes

“…The ε' ( f ) magnitude decreased slightly when the ac electric field frequency increased, this frequency‐dependent behavior of ε' ( f ) can be attributed to the reduction in the dielectric constant of PZT particles with increasing frequency, as well as due to space charge interfacial polarization ascribed to the Maxwell–Wagner–Sillars (MWS) effect 46,47 . This behavior has also been observed by the Riquelme and Raman 48 in lead‐free BZT‐BCT/PVDF flexible composites and is attributed to polarization relaxation and interface polarization of space charge, as well as to difficulty of the dipole orientation polarization in the internal structure at the high frequency regime of the piezoelectric composite 48 …”

“…46,47 This behavior has also been observed by the Riquelme and Raman 48 in lead-free BZT-BCT/PVDF flexible composites and is attributed to polarization relaxation and interface polarization of space charge, as well as to difficulty of the dipole orientation polarization in the internal structure at the high frequency regime of the piezoelectric composite. 48 In the low frequency region, ε'(f ) of all piezoelectric composite samples increased because of the tendency of dipoles to orient themselves in the direction of an ac electric field. In high frequency region, ε'(f ) remains almost constant, that is, the frequency-independent behavior of ε'(f ) poses great difficulty to the orientation/rotation of the dipoles in the composite since the periodic reversal of the ac electric field change so fast that no excessive diffusion of charge carrier in its direction occurs, therefore the polarization process caused by charge accumulation is reduced and, as a result, there is a decrease in ε'(f ).…”

Influence of Ferroelectric Filler Size and Clustering on the Electrical Properties of (Ag–BaTiO3)–PVDF Sub-Percolative Hybrid Composites

“…Trying to reach a more substantial permittivity increase in polymer-based composites, it was considered that employing ferroelectric fillers (in particular relaxor oxides, characterized by a very high permittivity of 10 4 –10 5 in their bulk form) would provide a significant increase in the composite’s effective dielectric constant. However, values of the effective permittivity were in the same range as when using BaTiO 3 or other normal ferroelectrics with a permittivity of about 10 2 –10 3 or even non-ferroelectric simple oxide fillers with permittivity of a few tens, in the same compositional range. ,− …”

Functionalized graphene oxide/polyvinylidene fluoride composite membrane acting as a triboelectric layer for hydropower energy harvesting

“…Under the electric field, the electrical hysteresis loop (P‐E) of PVDF, GO/PVDF, F‐GO/PVDF membranes show the polarization property at 1 Hz and room temperature (Figure 4G). As we know that the quantity of β phase present determines the intensity of polarization in the PVDF membrane 31,41 . Therefore, the PVDF membrane with the lowest β phase content shows a weak P‐E loop while those of the other two membranes show a high polarization strength.…”

“…As we know that the quantity of β phase present determines the intensity of polarization in the PVDF membrane. 31,41 Therefore, the PVDF membrane with the lowest β phase content shows a weak P-E loop while those of the other two membranes show a high polarization strength. It is noteworthy that the strongest polarization achieved in the PVDF membrane containing F-GO is 0.11 μC/cm 2 , which is 2 times higher than the neat PVDF membrane.…”