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

Abstract

Flexible inorganic-organic magneto-electric (ME) nanocomposite films (PVDF, PVDF-GO, PVDF-Fe3O4 and PVDF-GO-Fe3O4), composed of well-dispersed graphene oxide (GO 5 wt%) and magnetic Fe3O4 nanoparticles (5 wt%) embedded into a poly(vinylidene-fluoride) (PVDF) matrix, have been prepared by a solvent casting route. The magnetic, ferroelectric, dielectric, magneto-dielectric (MD) coupling and structural properties of these films have been systematically investigated. Magnetic (Ms = 2.21 emu g(-1)) and ferroelectric (P = 0.065 μC cm(-2)) composite films of PVDF-GO-Fe3O4 (PVDF loaded with 5% GO and 5% Fe3O4) with an MD coupling of 0.02% at room temperature (RT) showed a three times higher dielectric constant than that of the pure PVDF film, with a dielectric loss as low as 0.6. However, the PVDF-Fe3O4 film, which exhibited improved magnetic (Ms = 2.5 emu g(-1)) and MD coupling (0.04%) properties at RT with a lower dielectric loss (0.3), exhibited decreased ferroelectric properties (P = 0.06 μC cm(-2)) and dielectric constant compared to the PVDF-GO-Fe3O4 film. MD coupling measurements carried out as a function of temperature on the multi-functional PVDF-GO-Fe3O4 film showed a systematic increase in MD values up to 100 K and a decrease thereafter. The observed magnetic, ferroelectric, dielectric, MD coupling and structural properties of the nanocomposite films are attributed to the homogeneous dispersion and good alignment of Fe3O4 nanoparticles and GO in the PVDF matrix along with a partial conversion of nonpolar α-phase PVDF to polar β-phase. The above multi-functionality of the composite films of PVDF-Fe3O4 and PVDF-GO-Fe3O4 paves the way for their application in smart multiferroic devices.

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

“…The addition of GO, magnetic iron oxide (Fe 3 O 4 ) nanoparticles of size 10-12 nm, or the combination of both GO and Fe 3 O 4 led to the transformation of PVDF from the a-phase to the b-phase, which may be due to the heterogeneous nucleating effects of the nanoparticles and interfacial interactions. 182 With the addition of 5 wt% GO and 5 wt% Fe 3 O 4 , the maximum saturation polarisation was 0.065 mC cm À2 , this is higher than PVDF (mainly a-phase, 0.038 mC cm À2 ) and PVDF/Fe 3 O 4 (0.058 mC cm À2 ), but lower than that of PVDF/GO (0.1 mC cm À2 ), which may be due to the conducting nature of Fe 3 O 4 . A higher permittivity was observed for the composite lms (3 0 ¼ 12-19) than the pure PVDF lm (3 0 $ 6), with a dielectric loss of approximately 0.6.…”

Flexible electroactive PVDF/ZnO nanocomposite with high output power and current density

“…Polymers like polyvinylidene fluoride (PVDF) are widely used in harnessing energy from human locomotion due to their lightweight, flexibility, and inherent piezoelectric properties. [ 4, 5 ] They mainly exhibit four crystalline forms of which the polar β‐phase exhibits piezoelectric properties.. [ 6, 7 ] Conventionally, the PVDF films are prepared using techniques like melt casting, [ 8 ] spin coating, [ 9 ] solution casting, [ 10 ] phase‐inversion, [ 11 ] and compression molding. [ 12 ] However, they usually result in non‐polar α‐phase dominant films.…”

Mechanical, thermal, and dielectric properties of polyvinylidene fluoride nanocomposites fabricated by introducing functional MWCNTs/barium titanate compounding dielectric nanofillers

“…[2][3][4][5][6] In the past few years, it has been well established that electrically functional nanofillers could be introduced into PVDF matrix to fabricate PDNs. Functional nanofillers including ceramic fillers [7][8][9][10] (e.g., PbTiO 3 , CCTO, BaTiO 3 ) and conductive fillers [11][12][13][14] (e.g., Ni, GO, CNTs, Ag) have been widely researched in previous works. However, it seems inefficient and expensive due to high content requests for ceramic fillers (usually more than 50 vol%) in ceramic/PVDF nanocomposites in order to achieve a significant improvements in dielectric constant.…”