Abstract In contrast to the comprehensive understanding of novel ferroelectric [i.e., relaxor ferroelectric (RFE) and antiferroelectric] behavior in ceramics, RFE and double-hysteresis-loop (DHL) behavior in crystalline ferroelectric polymers have only been studied in the past fifteen years. A number of applications such as electrostriction, electric energy storage, and electrocaloric cooling have been realized by utilizing these novel ferroelectric properties. Nonetheless, fundamental understanding behind these novel ferroelectric behaviors is still missing for polymers. In this feature article, we intend to unravel the basic physics via systematic studies of poly(vinylidene fluoride- co -trifluoroethylene) [P(VDF-TrFE)]-based terpolymers, electron-beam (e-beam) irradiated P(VDF-TrFE) copolymers, and PVDF graft copolymers. It is found that both the crystal internal structure and the crystal–amorphous interaction are important for achieving the RFE and DHL behaviors. For the crystal internal structure effect, dipole switching with reduced friction and nanodomain formation by pinning the polymer chains are essential, and they can be achieved through crystal repeating-unit isomorphism (i.e., defect modification). Physical pinning [e.g., in P(VDF-TrFE)-based terpolymers] induces a reversible, electric field-induced RFE↔FE phase transition and thus the DHL behavior, whereas chemical pinning [e.g., in e-beam irradiated P(VDF-TrFE)] results in the RFE behavior. Finally, the crystal–amorphous interaction (or the nanoconfinement effect) results in a competition between the polarization and depolarization local fields. When the depolarization field becomes stronger than the polarization field, a DHL behavior is observed. Obviously, the physics for ferroelectric polymers is different from that for ceramics/liquid crystals and can be largely attributed to the long-chain nature of semicrystalline polymers. This understanding will help us to design new ferroelectric polymers with improved properties and/or better applications.

Novel Polymer Ferroelectric Behavior via Crystal Isomorphism and Nanoconfinement Effect

Rational design of nanomaterials for high energy density dielectric capacitors via electrospinning

Polymer dielectrics are the key component in film capacitors, which are one of the most fundamental elements in modern electronics and power systems [1–3]. Film capacitors are capable of storing energy when voltage is applied, in the form of electric charges separated by a dielectric material sandwiched by a pair of metal electrodes. Film capacitors possess the advantages of high breakdown strength, low power loss and processing flexibility compared with their counterparts in competition such as electrolytic capacitors and ceramic capacitors [4], meaning they can sustain high voltage, have great efficiency in electrical energy storage and can be manufactured in low-cost and efficient methods. Moreover, the unique self-clearing (sometimes referred to as self-healing) characteristic of polymer dielectrics ensures reliable operation of film capacitors [5], which is of paramount significance since capacitors storing a large amount of electrical energy can explode when catastrophic failure occurs. To be specific, the self-clearing is a process that when localized breakdown occurs at a spot of metallized film capacitors (i.e., a film capacitor using dielectric polymer films with metallic electrodes deposited on the surface [5], [6]), the energy released in the breakdown process can "clear" the breakdown-site, forming an open circuit. This process protects the capacitor from catastrophic failure (Figure 1) [7]. Serving as a device for charge storage and control, film capacitors are commonly used in many types of circuits such as snubbers, phase shifters, filters and AC/DC converters/inverters. In particular, film capacitors are capable of releasing the stored energy in an extremely short period of time to supply a high power density [8–10], which is desirable for the pulsed power application [1]. However, sizeable energy storage has not yet been achievable with film capacitors due to the limited volumetric energy density (usually measured in Joule per cubic centimeter at the material level). This shortcoming has caused a major issue in the electrical apparatus and electrified systems where capacitors constitute a large volume and weight fraction, i.e., a bulky, and sometimes even cumbersome size. For instance, in the 800 kV voltage source converter-based high voltage direct current transmission system, each converter tower has a volume of approximately 480 m3, where capacitors are ∼60% of the converter weight, and ∼50% of the volume.

Polymer nanocomposites for high-energy-density capacitor dielectrics: Fundamentals and recent progress

Towards high efficient nanodielectrics from linear ferroelectric P(VDF-TrFE-CTFE)-g-PMMA matrix and exfoliated mica nanosheets

Montmorillonite/PVDF-HFP-based energy conversion and storage films with enhanced piezoelectric and dielectric properties

Due to the appealing piezoelectric, pyroelectric, and ferroelectric (FE) properties, poly(vinylidene fluoride) (PVDF)-based dielectric polymers have been attracting great attention from both the academic and industrial communities. Depending on the molecular structure and the processing method, PVDF-based dielectric polymers can exhibit rich dielectric polarisation behaviours covering normal FE, relaxor FE, anti-FE-like and linear dielectric responses, which enables a wide spectrum of application fields such as non-volatile memories, piezoelectric and pyroelectric sensors, actuators, electrocaloric refrigeration, and film capacitors. In this study, the authors first briefly introduce the current practical/promising applications of PVDF-based dielectric polymers, and the corresponding optimum dielectric polarisation behaviour and crystal structure are proposed accordingly. The chemical synthesis and modification strategies for obtaining various fluoropolymers beyond PVDF homopolymer are then summarised with an emphasis on the relationship between the molecular structure and the dielectric polarisation behaviour. In addition, the effect of processing methods on the crystal structure and dielectric properties of the PVDF-based polymers is discussed. Finally, some newly developed processing techniques applicable to PVDF-based polymers are described.

Design, synthesis and processing of PVDF-based dielectric polymers

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Shan Wang

Author Tools

Chat about Author

Papers

Design, synthesis and processing of PVDF-based dielectric polymers