Improvement of Magnetodielectric Coupling by Surface Functionalization of Nickel Nanoparticles in Ni and Polyvinylidene Fluoride Nanohybrids

Abstract

A facile surface hydroxylation treatment to modify the surface of nickel nanoparticles dispersed in ferroelectric polyvinylidene fluoride (PVDF) is reported. A remarkable increase in the amount of polar β phase of PVDF has been observed upon dispersion of nickel nanoparticles in the PVDF matrix. The leakage current reduces drastically in the composite with surface-modified nickel nanoparticles. This improvement has been observed with concurrent enhancement of electrical polarization in the surfacemodified nickel−PVDF composite. However, the magnetic moment of the modified composite is found to be slightly lower than that of the unmodified composite. Most importantly, the composite with surface-modified nickel exhibits magnetodielectric coupling significantly higher than that of the unmodified composite. The magnetodielectric coupling appears to be facilitated by surface hydroxyl groups on nickel. These results establish the potential of facile surface functionlization of nanoparticles toward the design of nanocomposites with higher magnetoelectric coupling.

Improvement of β-phase crystal formation in a BaTiO3-modified PVDF membrane

“…This implies that the β-phase induction effect of the BaTiO 3 nanoparticles was greatly improved by the plasma modification. This result was consistent with the reports on surface-modified nickel −PVDF composite by Mandal et al [45] and the PVDF/CNT system prepared by solution sonication by Yu et al [46]. Melting curves of the PVDF/BaTiO 3 membranes at different processing voltages are displayed in figure 6.…”

4′‐Chlorochalcone‐Assisted Electroactive Polyvinylidene Fluoride Film‐Based Energy‐Storage System Capable of Self‐Charging Under Light

“…The interaction and different phases of the CPP‐doped PVDF films and pure PVDF were investigated by using XRD (Figure b). The diffraction peaks that correspond to the nonpolar α phase at approximately 2 θ =17.6° (1 0 0), 18.3° (0 2 0), 19.9° (0 2 1), and 26.6° [(2 0 1), (3 1 0)] are completely diminished in the diffraction patterns of chlorochalcone‐doped PVDF samples, and only one peak at approximately 20.5° [(1 1 0), (2 0 0)] is prominent, which confirms the nucleation of the electroactive β polymorphs in the PCC samples . In the XRD patterns of the PCC samples that have a high concentration of chlorochalcone, we also observe a small peak at approximately 2 θ =24.3°, which is characteristic of chlorochalcone (Figure S3 in the Supporting Information).…”

“…In the XRD patterns of the PCC samples that have a high concentration of chlorochalcone, we also observe a small peak at approximately 2 θ =24.3°, which is characteristic of chlorochalcone (Figure S3 in the Supporting Information). The amounts of the α and β phases in the samples were measured qualitatively by the ratio of the peaks intensities at 20.5° and 18.3° ( I 20.5 / I 18.3 ; Figure c) . The maximum value of the ratio is 28.3 obtained for PCC20.…”

Fabrication of flexible and self-standing inorganic–organic three phase magneto-dielectric PVDF based multiferroic nanocomposite films through a small loading of graphene oxide (GO) and Fe3O4nanoparticles

“…11, which shows MD at 300 K and 30 kHz, it can be observed that diamagnetic PVDF and PVDF-GO samples do not show any change in dielectric constant upon the application of the magnetic field, as expected. On the other hand, the samples loaded with magnetic Fe 3 O 4 show variation in dielectric constant upon the application of the magnetic field, with the samples PVDF-Fe 3 O 4 and PVDF-GO-Fe 3 O 4 showing a MD of ∼0.035% and 0.02%, respectively, at 300 K. It may be noted that Mandal et al 59 studied the dielectric and magneto-dielectric coupling (MD%) properties of a hydroxylated Ni-PVDF based system and have observed that the magneto-dielectric coupling value of Ni-PVDF samples was about 0.02% at room temperature. Our present sample (PVDF-GO-Fe 3 O 4 ) shows a higher MD coupling (0.04%) at room temperature compared to the Ni-PVDF sample.…”