Nanoparticle-Enhanced β-Phase Formation in Electroactive PVDF Composites: A Review of Systems for Applications in Energy Harvesting, EMI Shielding, and Membrane Technology

Abstract

With the continuous advancement of electronic devices, lightweight, flexible, and easily processable materials have gained substantial techno-commercial importance. Most electronic devices must possess a lightweight, high conductivity, high dielectric permittivity, low dielectric loss, and high breakdown strength. Hence, polymer-based piezoelectric materials are in great demand for design and development in energy storage, electromagnetic interference (EMI) shielding, and ultrafiltration applications. Among the piezoelectric polymers, poly­(vinylidene fluoride) (PVDF) with a predominantly polar β-phase is the most important. However, the main drawbacks of the PVDF matrix are its relatively low electrical conductivity and dielectric permittivity, and poor energy harvesting and EMI shielding performance. In this context, the incorporation of conductive nanofillers such as reduced graphene oxides, graphene quantum dots, and carbon nanotubes in the PVDF matrix has attracted considerable interest owing to their extraordinary properties. The final properties of these piezoelectric composites depend on the preparation methods, structural conformation, processing conditions, dispersion of nanofillers in the matrix, surface modification of fillers, and specific or nonspecific interaction of the fillers with the PVDF matrix. Herein, we have critically reviewed the formation mechanism of the electroactive β-phase in PVDF, the effects of nanofillers on the phase transformation of PVDF (dispersion and specific interaction), and the correlation of β-phase PVDF piezoelectric and dielectric properties with energy harvesting, EMI shielding, and membrane applications.

Boosting Energy Storage of Poly(vinylidene difluoride) Nanocomposite Based Flexible Self-Standing Film with Low Amount of Hydroxylated V2O5

“…After processing PVDF powder to PVDF film, the high intensity peaks of α-, β-, and γ-phases present at 2θ corresponding to 18.4°, 26.5°, 20.6°, 36.1°and 18.5°, 20.3°, 39.4°, respectively, are observed, as shown in Figure 2. 2,32 From previous literature reports, the PVDF film developed by the solution cast method in the solvent N,N-dimethylformamide at a temperature of 100 °C shows the presence of the α-, β-, and γ-phase. 33 The PVDF film shows a semicrystalline nature.…”

“…The increasing demand for electric vehicles and portable and wearable devices has made the researcher focus on flexible energy storage solutions. In recent years, polymer composites have attracted attention due to high energy density with extraordinary dielectric properties of some chosen functional inorganic fillers and the high breakdown strength, processability, and mechanical performance of a polymer matrix. , The ferroelectric polymers have high breakdown strength ( E b ) and low dielectric loss tan­(δ), but pure polymer has a much less dielectric constant around 10–15. However, ceramic ferroelectric materials like PbTiO 3 and BaTiO 3 etc.…”

“…have a higher dielectric constant around ε > 1000 due to large polarization but have a relatively lower dielectric breakdown strength than polymers . The addition of both provides enhanced dielectric properties depending on the type and nature of polymer matrices as well as fillers. , There are various types of polymers that are being used to prepare polymer composites on the basis of their properties including epoxy, polyimides, poly­(methyl methacrylate) (PMMA), and polydimethylsiloxane (PDMS) etc . Biaxial-oriented polypropylene (BOPP), the best commercial polymer ferroelectric material, has very low value of energy density ( U d ) = (1.2 J/cm 3 ) because of the low ε r which seriously limits its applications …”

Multi-responsive 3D Structured PVDF Cube Switch for Security System Using Piezoelectric Anisotropy

“…In this study, we employ this property to develop a device that operates with a single input to provide multiple output responses in accordance with the force and piezo element directions derived from the polarization direction. Previous studies on PVDF lms have generally focused on advancing fabrication methods, such as patterning processes [21,22] or modifying the molecular phase [23,24]. However, applications of PVDF lms with anisotropic [25] and three-dimensional (3D) structures have rarely been introduced.…”

Influencing the Crystalline Domains of Poly(vinylidenedifluoride) Composites Using Fluorinated Silica Nanoparticles as Drop-In Modifiers

“…On the other hand, partially fluorinated poly(vinylenedifluoride) - CF 2 CH 2 - (PVDF) is one of the most versatile fluoropolymers used in a plethora of manufacturing techniques and is highly adaptable to solvent blending for films and coatings, as well as melt processing for injection molded parts or drawn fibers [ 5 ]. Additionally, the ability to incorporate fillers such as particles and fibers, for example, demonstrates PVDF’s greater utility by manipulating its crystalline microstructure to enrich desired β-phase domains in order to hone in on its intrinsic properties as a novel piezoelectric material [ 6 ].…”