Enhancement of electroactive β phase crystallization and dielectric constant of PVDF by incorporating GeO₂ and SiO₂ nanoparticles

Abstract

Poly(vinylidene fluoride) (PVDF) nanocomposites are recently gaining importance due to their unique dielectric and electroactive responses. In this study, GeO2 nanoparticles/PVDF and SiO2 nanoparticles/PVDF nanocomposite films were prepared by a simple solution casting technique. The surface morphology and structural properties of the as-prepared films were studied by X-ray diffraction, scanning electron microscopy, and FT-IR spectroscopy techniques. The studies reveal that the incorporation of GeO2 or SiO2 nanoparticles leads to an enhancement in the electroactive β phase fraction of PVDF due to the strong interactions between the negatively charged nanoparticle surface and polymer. Analysis of the thermal properties of the as-prepared samples also supports the increment of the β phase fraction in PVDF. Variation of dielectric constant, dielectric loss, and ac conductivity with frequency and loading fraction of the nanoparticles were also studied for all the as-prepared films. Dielectric constant of the nanocomposite films increases with increasing nanofiller concentration in PVDF. 15 mass% SiO2-loaded PVDF film shows the highest dielectric constant, which can be attributed to the smaller size of SiO2 nanoparticles and the homogeneous and discrete dispersion of SiO2 nanoparticles in PVDF matrix.

Multiscale-structuring of polyvinylidene fluoride for energy harvesting: the impact of molecular-, micro- and macro-structure

“…A 15 wt% SiO 2 -loaded PVDF lm exhibited a high permittivity, due to the homogeneous dispersion and interfacial interaction of SiO 2 nanoparticles in the PVDF matrix. 131 For a P(VDF-co-HFP) matrix lled with mesoporous SiO 2 nanorods, the anisotropic shape of the SiO 2 nanorods and ordered mesopores doubled the amount of the -OH groups present. This increased the intermolecular interactions and enhanced the bphase content and ferroelectric properties of P(VDF-co-HFP).…”

Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites

“…However, the value of the dielectric constant is low as compared to that of the PVDF-KNN nanocrystal composites. The increase in dielectric constant in the nanocrystal composites is chiefly attributed to an increase in dipole-dipole interaction between the PVDF polymer and the KNN nanocrystals at the interface and also due to ion-dipole interaction between the surface of the nanocrystallites and the PVDF matrix [18,[54][55][56][57][58].…”

Preparation ofCuONPs@PVDF/Non-Woven Polyester Composite Membrane: Structural Influence of Nanoparticles Addition

“…The infrared spectrum of the PVDF films prepared in presence of CuONPs is shown in Figure 3b). Apparently, the presence of CuONPs did not dramatically affect the intensity and wavenumber It is reported that the addition of metal oxide nanoparticles to the PVDF casting solution causes the -to -phase conversion [13,22]. As can be noted, the F() values are similar within the studied CuONPs composition range (2-10 wt.…”

“…The infrared spectrum of PVDF mainly covers the low wavenumber region (Figure 3b). The -CF2 wagging (489 cm -1 ) and bending (610 cm -1 ), the skeletal bending (764 cm -1 ), the -CH2 rocking (795 cm -1 ) and twisting (975 cm -1 ) are some of the peaks characteristic of the non-polar -phase of PVDF (indicated by black arrows, Figure 3a) [13,21,22]. Two peaks, labeled with black arrows in Figure 3a (at 510 cm -1 and 840 cm -1 corresponding to the -CF2 stretching -CH2 rocking, respectively)…”

“…The intensity of the peak at 840 cm -1 suggests an important contribution of the polar -PVDF to the polymer structure. Interestingly, in neat PVDF prepared by phase inversion methods, the fraction of the polar -phase in the polymer structure is very low (F()<35%) [13,22]. The F() value of the polymer deposited onto the non-woven PET indicates that the 53 % corresponds to the -phase.…”