Preparation and characterization of flexible PVDF-HFP film for piezoelectric applications

Abstract

We report on the preparation of electroactive β-phase in polyvinylidene fluoride hexafluoropropylene (PVDF-HFP) without any electrical poling treatment. The PVDF-HFP film with various mass fractions (wt%) of magnesium chloride hexahydrate salt (MgCh∼6H2O) was fabricated by a solution casting technique. The morphological, mechanical, structural and dielectric properties were investigated. Results founded that the PVDF-HFP composite films show a large number of micro-pores on the top surface as a sponge-like structure. The Young’s modulus and crystallinity values tend to be linearly decreased with the MgCh2⋗6H2O concentration leading to enhance flexibility. The largest β-phase fraction of 87.2% is found in the composite with 1 wt% MgCh2⋗6H2O filler. The obtained value is 4 times higher than the value of unfilled PVDF-HFP. Moreover, the maximum value of dielectric constant is about 19.2 at 10 Hz for 4 wt% MgCh2⋗6H2O filler. Therefore, the modified composites with the excellent flexibility, dielectric constant and β-phase may be a promising material for applications in the field of piezoelectric energy conversion.

Enhancement of piezoelectric β‐polymorph formation and properties of graphene oxide and PZT‐incorporated in PVDF‐HFP matrix for energy harvesting applications

“…As a result, a highly flexible film develops significantly and deforms easily when a force is applied, indicating that the composite sample is more suitable for piezoelectric applications. [ 50 ]…”

Enhanced electroactive β‐phase and dielectric properties in P(VDF‐HFP) composite flexible films through doping with three calcium chloride salts: CaCl2, CaCl2·2H2O, and CaCl2·6H2O

“…Furthermore, the values for tensile strength and elongation at break of the composites consistently decline with an increase in calcium salt concentrations, regardless of the type of salt. This can be attributed to the interaction between the salt filler and the polymer matrix, which restricts the mobility of polymer chains, leading to a decrease in tensile strength and elongation at break with increased filler loading 62,63 …”

“…This can be attributed to the interaction between the salt filler and the polymer matrix, which restricts the mobility of polymer chains, leading to a decrease in tensile strength and elongation at break with increased filler loading. 62,63 The enhancement in the mechanical properties of the nanocomposite films, associated with enhanced salt loading, is attributed to the homogeneous dispersion of salts in the polymer matrix, as depicted in the SEM image in Figure 3. Additionally, the constrained mobility of the P(VDF-HFP) polymer chains, coupled with the ongoing increase in salt molecular weight, likely results in a reduction in the crystallinity of the composites, as elucidated in the subsequent XRD results.…”

Al2O3/graphene/PVDF‐HFP radiative cooling coating reinforced heat dissipation of BIPV modules

“…28 Reducing the acoustic impedance mismatch between the polymer matrix and the solid filler is equivalent to reducing the modulus mismatch, thereby reducing the interfacial thermal resistance and improving the thermal conductivity of the polymer material. [29][30][31] Because the modulus of alumina ($380 GPa 32 ) is between graphene ($1100 GPa 33,34 ) and PVDF-HFP ($1.56 GPa 35 ), the addition of alumina reduces the modulus mismatch between graphene and PVDF-HFP, thus effectively decreases the interfacial thermal resistance of Al 2 O 3 /graphene/PVDF-HFP composite coatings, and improves the thermal conductivity. Therefore, it is helpful to enhance the heat dissipation performance of the composite coatings.…”