Download or read book New Properties and Applications of Polyvinylidene Based Ferroelectric Polymer written by J.L. Wang and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There are different kinds of novel properties and applications of polyvinylidene difluoride (PVDF)-based ferroelectric polymer films. Several issues associated with the structure, properties, and applications of PVDF-based ferroelectric polymer films are discussed. The main achievements of the research include high electric tunability of relaxor ferroelectric Langmuir-Blodgett (LB) terpolymer films, the creep process of the domain switching in poly(vinylidene fluoride-trifluoroethylene) ferroelectric thin films, transition from relaxor to ferroelectric-like phase in poly(vinylidene fluoride-trifluoroethylene -chlorofluoroethylene) terpolymer ultrathin films, abnormal polarization switching of relaxor terpolymer films at low temperatures, huge electrocaloric effect in LB ferroelectric polymer thin films, self-polarization in ultrathin LB polymer films, enhanced dielectric and ferroelectric properties in artificial polymer multilayers, and transition of polarization switching from extrinsic to intrinsic in ultrathin PVDF homopolymer films.
Download or read book Ferroelectric Materials written by Aimé Peláiz-Barranco and published by BoD – Books on Demand. This book was released on 2015-07-29 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferroelectric materials receive great attention from the scientific international community because of the interesting phenomena they exhibit and their multiple applications such as transducers, capacitors, pyroelectric sensors, sonars, random access memories, etc. The demand for ferroelectric materials for technological applications enforced the in-depth research, in addition to the improvement of processing and characterization techniques. This book contains nine chapters and offers the results of several researches covering fabrication, properties, theoretical topics, and phenomena at the nanoscale.
Download or read book PVDF Based Ferroelectric Polymers written by and published by de Gruyter. This book was released on 2017-05-23 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book begins by introducing signals and systems, and then discusses Time-Domain analysis and Frequency-Domain analysis for Continuous-Time systems. It also covers Z-transform, state-space analysis and system synthesis. The author provides abundant examples and exercises to facilitate learning, preparing students for subsequent courses on circuit analysis and communication theory.
Download or read book Ferroelectric Polymers written by Hari Singh Nalwa and published by CRC Press. This book was released on 1995-06-20 with total page 913 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work covers the chemistry and physics of polymeric materials and their uses in the fields of electronics, photonics, and biomedical engineering. It discusses the relationship between polymeric supermolecular structures and ferroelectric, piezoelectric and pyroelectric properties.
Download or read book Understanding the Composition structure property Relationships and Enhancing the Electromechanical Responses in Ferroelectric Polymers written by Zhubing Han and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Poly(vinylidene fluoride) (PVDF)-based ferroelectric polymers enable a wide range of advanced applications with new functionalities and structure designs due to their high electroactivity, intrinsic flexibility and biocompatibility. One unique feature of these polymers is that their dielectric, ferroelectric and electromechanical properties can be modulated by varying their chemical composition and the processing conditions. Despite the progress over the last decades, a more comprehensive understanding on the composition--structure--property relationships in PVDF-based ferroelectric polymers is still needed to achieve rational design of new materials with enhanced performance. The scope of this dissertation aims to understand the influence of monomer defects on the structures and ferroelectric properties of PVDF-based terpolymers, and to enhance their electromechanical performance enabled by the rational design of new polymer structures and compositions. After a general background introduction, the dissertation starts with two chapters discussing the effect of two different comonomers as chain defects on the structures and ferroelectric properties of the corresponding terpolymers. Chapter 2 reveals that the incorporation of bulky 2-chloro-1,1-difluoroethylene (CDFE) can gradually convert the ferroelectric P(VDF-TrFE) (TrFE: trifluoroethylene) into a relaxor ferroelectric terpolymer as confirmed by the dielectric and structural characterizations. The CDFE comonomer serves as an effective chain defect to destabilize the ferroelectric domain by introducing the gauche conformation. The P(VDF-TrFE-CDFE) with 3.8 mol% CDFE exhibits typically relaxor ferroelectric behaviors such as strong frequency-dependence of dielectric properties, broad and diffuse ferroelectric phase transition, and weak remanent polarization. Chapter 3 systematically investigates the effect of another comonomer defect, vinyl fluoride (VF), which has a smaller size than VDF. It is found that VF plays an opposite role compared with the bulky chlorinated comonomers. Increasing molar content of VF leads to an increase in the Curie temperature and the coercive field of the terpolymers. Structural characterizations and simulations evidences confirm that the all-trans conformation remain energetically more favored than the gauche conformation regardless of the VF content. The results stress the vital role of comonomer structure and size in modulating the structures and properties of the ferroelectric polymers. The next two chapters focus on improving the electromechanical performance of the PVDF-based polymers. In Chapter 4, a series P(VDF-TrFE-CTFE) (CTFE: chlorotrifluoroethylene) with systematic composition variations have been synthesized. Structural characterizations show that the terpolymers with 1.7 to 5.0 mol% CTFE exhibit a mixture and competition of the normal ferroelectric and relaxor ferroelectric phases as a result of the incorporation of CTFE. Specifically, a maximum longitudinal piezoelectric coefficient (d33) of -55.4 pm/V has been observed in P(VDF-TrFE-CTFE) 64.5/33.1/2.4 mol%, corresponding to an 85% improvement compared with the commercial benchmark P(VDF-TrFE) 65/35 mol%. This strategy can potentially be expanded to other polymer systems to improve the piezoelectric response. Chapter 5 aims to enhance the low-electric-field electrostrictive strain in relaxor ferroelectric polymers. The small electrostrain of current relaxor ferroelectric P(VDF-TrFE-CFE) (CFE: 1-chloro-1-fluoroethylene) and P(VDF-TrFE-CTFE) terpolymers at low electric field impedes their usefulness in actuating devices. In situ structural characterizations under the electric field reveal that the electrostrictive strain originates from the field-induced phase transition in P(VDF-TrFE-CFE) and the lattice compression in P(VDF-TrFE-CTFE). Inspired by the distinct functions of CFE and CTFE, a series of P(VDF-TrFE-CFE-CTFE) tetrapolymers have been synthesized, which exhibit significant enhancement of electrostrictive strain at both low and high electric fields due to the synergistic effect of CFE and CTFE. These results provide new insight into the origin of electrostriction in the relaxor ferroelectric polymers, and the tetrapolymers in this study can potentially be used to prototype soft actuators. It is anticipated that the materials, methodologies and results developed in this dissertation will not only provide new insights and understandings on the structure-property relationship in ferroelectric polymers, but also stimulate future work to further enhance the performance in these materials in order to meet the material requirement for practical applications.
Download or read book The Applications of Ferroelectric Polymers written by T. T. Wang and published by Springer. This book was released on 1988-06-30 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of 4th International Conference on Electrochemistry 2018 written by ConferenceSeries and published by ConferenceSeries. This book was released on with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: June 11-12, 2018 Rome, Italy Key Topics Theoretical and Computational Electrochemistry, Physical and Analytical Electrochemistry, Photoelectrochemistry, Electrochemical Energy, Sensors, Organic and Bioelectrochemistry, Batteries and Energy Storage, Corrosion Science and Technology, Electronic Materials and Processing, Carbon Nanostructures, Dielectric Science and Materials, Electrochemical Electroless Deposition, Electrochemical Water Treatment, Electrochemical Surface Science, Electrochemical Engineering, Environmental Electrochemistry, Applied Electrochemistry, Inorganic Electrochemistry, Market Surveillance of Electrochemistry,
Download or read book Development of the Piezoelectric Properties of Poly vinylidene Fluoride Based Ferroelectrics and Ferroelectrets Using Fillers and Mechanical Stretching written by Nusrat Jahan and published by . This book was released on 2018 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric polymers are very useful in various electromechanical applications because of their strong piezoelectric response, flexibility, lightweight and formability. In addition to ferroelectric ceramics, ferroelectric polymers (such as PVDF) and ferroelectrets are also popular as a new group of piezoelectrics. Ferroelectrics based on b-PVDF are interesting due to the ease of preparation with usable piezoelectric response in addition to the above mentioned advantages of polymers. Incorporating nanofillers (e.g. ceramic filler-BaTiO3, PZT, carbon nanotube, clay, ferrite nanoparticles etc.) into PVDF is one of the facile ways to produce b phase in PVDF often followed by mechanical stretching. While fillers nucleate b phase in the PVDF matrix, subsequent mechanical stretching helps in aligning the dipoles to some extent. Therefore, the aim of the first part of this study is to prepare ferroelectric b-PVDF films by incorporating a hybrid filler (micro-CaCO3+ nanoclay) followed by mechanical stretching. While nanoclay is one of the most widely used cost-effective fillers capable of nucleating b-PVDF, synergistic improvement in b phase formation as well as in mechanical, electrical and piezoelectric properties of hybrid composites have been reported in this part of the study. Additionally, the influence of subsequent mechanical stretching e.g. draw ratio, R (final length/initial length), has also been investigated. FTIR and XRD are employed to determine the b phase content in both stretched and unstretched samples. While the tensile properties show a gradual decrease, dielectric constant increased gradually with increasing CaCO3 content in the hybrid filler. The maximum piezoelectric d33 coefficient of 30 pC/N is obtained for stretched hybrid composite films. Ferroelectrets, on the other hand, are another type of functional polymer films with heterogeneous cellular structure and internal quasi-permanent dipole moments. The piezoelectricity in ferroelectrets originates from the change in dipole moments under an applied mechanical stress. Over the past few decades, cellular polypropylene (PP) films have been the most popular and widely investigated ferroelectrets and are already in commercial applications. While the piezoelectric d33 coefficient of PP ferroelectrets could exhibit up to 1000 pC/N or more, their working temperature is quite low, not higher than 60 °C. Recently developed fluoropolymer i.e. polytetrafluoroethylene (PTFE) and fluoroethylene propylene (FEP) based ferroelectrets exhibit strong piezoelectric response and excellent thermal stability. However, processing these fluoropolymer ferroelectrets using commercially viable manufacturing technique such as cast film extrusion poses few challenges because of their very high melt viscosity, high manufacturing temperature, degradation tendency and low tensile elongation. Therefore, in this part of the study, a new thermally stable ferroelectret has been investigated using commercial processing technique with strong piezoelectric response. Cast extrusion of the polymer/filler mixture followed by mechanical stretching is one of the promising techniques for preparing a cellular polymer. Micron scale fillers are usually employed for creating voids from interfacial delamination under applied stress. Polyvinylidene fluoride (PVDF) is a fluoropolymer which is easily melt-processable than other fluoropolymers and showing excellent physical, chemical and electrical properties. An "extrusion-stretching-inflation" process has been followed to prepare a cellular structure in PVDF films. Solid PVDF/hybrid filler (micro-CaCO3 + nanoclay) films were extruded and subsequently stretched to create the initial cellular structure inside the films. While CaCO3 acts as void nucleation centers, nanoclay increases the stretchability of the highly CaCO3 filled PVDF films. Gas diffusion expansion (GDE) or controlled inflation is preformed to adjust the voids dimensions to lens-shaped voids leading to lower elastic moduli and stronger piezoelectricity. Obviously, the gas permeation characteristics in polar polymers is different than non-polar polymers because of their different type of polymer/gas interaction and the final piezoelectric properties of the ferroelectrets strongly depend on the cellular morphology such as void size, shape and distribution. Therefore, two different inflation gases i.e. neutral N2 and polar CO2 are used with various inflation strategies. Combination of pressure, temperature and their way of application (direct or step-wise) is examined for various times to optimize the inflation level. The inflated films are then subjected to corona charging at room temperature to create the dipoles inside the voids. Finally, PVDF ferroelectrets show piezoelectric d33 coefficient as high as 251 pC/N with N2 inflation and 327 pC/N for CO2 treatment. As expected, PVDF ferroelectrets exhibit better thermal stability than PP, PETP, COP and PEN and as high as Teflon. Samples charged at room temperature have their working temperature up to 120 °C
Download or read book Confined Ferroelectric Properties in Poly vinylidene Fluoride PVDF based Random Copolymers and Graft Copolymers for Electric Energy Storage Applications written by Fangxiao Guan and published by . This book was released on 2010 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of High Pressure in the Study and Applications of the Ferroelectric Polymer Polyvinylidene Fluoride and Its Copolymers written by and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of frequency, temperature and hydrostatic pressure on dielectric properties, molecular relaxations, and phase transitions of PVDF and a copolymer with 30 mol % trifluoroethylene are discussed. Pressure causes large slowing down of the [beta] molecular relaxations as well as large increases in the, ferroelectric transition temperatures and melting points, but the magnitudes of the effects are different for the different transitions. These effects can be understood in terms of pressure-induced hindrance of the molecular motions and/or reorientations. A unique application of these polymers as time-resolved dynamic stress gauges based on PVDF studies under very high pressure shock compression is discussed.
Download or read book Ferroelectrics written by Ashim Kumar Bain and published by John Wiley & Sons. This book was released on 2017-01-30 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combining both fundamental principles and real-life applications in a single volume, this book discusses the latest research results in ferroelectrics, including many new ferroelectric materials for the latest technologies, such as capacitors, transducers and memories. The first two chapters introduce dielectrics and microscopic materials properties, while the following chapter discusses pyroelectricity and piezoelectricity. The larger part of the text is devoted to ferroelectricity and ferroelectric ceramics, with not only their fundamentals but also applications discussed. The book concludes with a look at the future for laser printed materials and applications. With over 600 references to recent publications on piezoelectric and ferroelectric materials, this is an invaluable reference for physicists, materials scientists and engineers.
Download or read book Ferroelectric Polymers for Organic Electronic Applications written by Nicoletta Spampinato and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic electronics represent a realistic alternative to conventional silicon-based technologies through the design, synthesis and implementation of functional organic materials into light and flexible devices. Organic materials, such as small molecules or organic polymers, are advantageous for their low-cost, flexibility and easy processing. Thanks to the economical and timesaving advantages, organic electronics have emerged as an innovative field with application in energy, environment, health, information and communication technologies.Organic electronics originates from the discovery of polymers with semiconducting functionalities. However, one should not neglect another class of outstanding polymers, the ferroelectric polymers. The electroactive nature of ferroelectric polymers, which are also pyroelectric and piezoelectric, combined with the intrinsic advantages of polymers have designated them as constituent elements of a widespread range of organic electronic devices. The most well-known family of ferroelectric polymers is that of poly(vinylidene fluoride), P(VDF), and its copolymers with trifluoroethylene, P(VDF-co-TrFE). Energy harvesting, data storage and sensing, main applications of organic electronics, can potentially all be realised using these exceptional functional materials.Since ferroelectricity is a structure-dependent property an insight into the interrelations between structure and final ferroelectric properties is indispensable in order to improve existing applications of ferroelectric polymers in organic electronics and to promote the introduction of P(VDF-co-TrFE) in new application fields. P(VDF-co-TrFE) as semi-crystalline polymer possess crystalline properties which are sensitive to thermal treatment. Since only the crystalline regions contribute to ferroelectric switching and not the amorphous ones, the degree of crystallinity is a key factor to modulate the ferroelectric properties. Moreover, crystallites orientation as well as the presence of defects within the crystallites are crucial parameters playing an important role in defining the final performance of the devices in which P(VDF-co-TrFE) is incorporated.Herein stands the aim of this thesis: reach an exhaustive understanding of processing-structure-function relationships that will serve as tool to modulate ferroelectric devices performances.Going one step further, the potential applications of P(VDF-co-TrFE) in organic electronics are explored by investigating it in: (1) medical piezoelectric catheter sensors for measuring cardiac function and eventually for detecting cardiac disease and (2) electronic devices in which P(VDF-co-TrFE) is blended with the semiconducting polymer poly(3-hexylthiophene), P3HT. The latter has already been applied in non-volatile ferroelectric memory diodes and the potential use in organic photovoltaics is explored.
Download or read book Ferroelectric Materials for Energy Applications written by Haitao Huang and published by John Wiley & Sons. This book was released on 2019-01-04 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive overview of the emerging applications of ferroelectric materials in energy harvesting and storage Conventional ferroelectric materials are normally used in sensors and actuators, memory devices, and field effect transistors, etc. Recent progress in this area showed that ferroelectric materials can harvest energy from multiple sources including mechanical energy, thermal fluctuations, and light. This book gives a complete summary of the novel energy-related applications of ferroelectric materials?and reviews both the recent advances as well as the future perspectives in this field. Beginning with the fundamentals of ferroelectric materials, Ferroelectric Materials for Energy Applications offers in-depth chapter coverage of: piezoelectric energy generation; ferroelectric photovoltaics; organic-inorganic hybrid perovskites for solar energy conversion; ferroelectric ceramics and thin films in electric energy storage; ferroelectric polymer composites in electric energy storage; pyroelectric energy harvesting; ferroelectrics in electrocaloric cooling; ferroelectric in photocatalysis; and first-principles calculations on ferroelectrics for energy applications. -Covers a highly application-oriented subject with great potential for energy conversion and storage applications. -Focused toward a large, interdisciplinary group consisting of material scientists, solid state physicists, engineering scientists, and industrial researchers -Edited by the "father of integrated ferroelectrics" Ferroelectric Materials for Energy Applications is an excellent book for researchers working on ferroelectric materials and energy materials, as well as engineers looking to broaden their view of the field.
Download or read book Magnetoelectric Polymer Based Composites written by Senentxu Lanceros-Méndez and published by John Wiley & Sons. This book was released on 2017-06-21 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on this topic provides a comprehensive and well-structured overview of the fundamentals, synthesis and emerging applications of magnetoelectric polymer materials. Following an introduction to the basic aspects of polymer based magnetoelectric materials and recent developments, subsequent chapters discuss the various types as well as their synthesis and characterization. There then follows a review of the latest applications, such as memories, sensors and actuators. The book concludes with a look at future technological advances. An essential reference for entrants to the field as well as for experienced researchers.
Download or read book Effects of Configurational Changes on Molecular Dynamics in Polyvinylidene Fluoride and Poly vinylidene Fluoride trifluoroethylene Ferroelectric Polymers written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we present a comparative study of proton dynamics in unpoled non-ferroelectric polymer polyvinylidene fluoride (PVDF) and in its trifluoroethylene containing ferroelectric copolymer (with 70/30 molar proportion), using quasi-elastic neutron scattering. The neutron data reveal the existence of two distinct types of molecular motions in the temperature range investigated. Moreover, the slower motion, which is characterized in details here, is ascribed to protons jump diffusion along the polymeric carbon chains, while the faster motion could be attributed to localized rotational motion of methylene groups. At temperatures below the Curie point (T-c similar to 385 K) of the composite polymer, the slower diffusive mode experiences longer relaxation times in the ferroelectric blend than in the bare PVDF, although the net corresponding diffusion coefficient remains comparatively the same in both polymers with characteristic activation energy of E-A approximate to 27-33 kJ/mol. This arises because of a temperature dependent jump length r(0), which we observe to be effectively longer in the copolymer, possibly due to the formation of ordered ferroelectric domains below Tc. Above Tc, there is no appreciable difference in r(0) between the two systems. Our observation directly relates the known dependence of Tc on molar ratio to changes in r(0), providing fundamental insight into the ferroelectric properties of PVDF-based copolymers.
Download or read book Organic Ferroelectric Materials and Applications written by Kamal Asadi and published by Woodhead Publishing. This book was released on 2021-10-27 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic Ferroelectric Materials and Applications aims to bring an up-to date account of the field with discussion of recent findings. This book presents an interdisciplinary resource for scientists from both academia and industry on the science and applications of molecular organic piezo- and ferroelectric materials. The book addresses the fundamental science of ferroelectric polymers, molecular crystals, supramolecular networks, and other key and emerging organic materials systems. It touches on important processing and characterization methods and provides an overview of current and emerging applications of organic piezoelectrics and ferroelectrics for electronics, sensors, energy harvesting, and biomedical technologies. Organic Ferroelectric Materials and Applications will be of special interest to those in academia or industry working in materials science, engineering, chemistry, and physics. Provides an overview of key physical properties of the emerging piezoelectric and ferroelectric molecular and supramolecular systems Discusses best practices of processing, patterning, and characterization methods and techniques Addresses current and emerging applications for electronics, materials development, sensors, energy harvesting, and biomedical technologies
Download or read book Novel Ferroelectric Behavior in Poly vinylidene Fluoride co trifluoroethylene based Random Copolymers written by Lianyun Yang and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High dielectric constant and low loss polymer dielectrics are desired for applications such as energy storage, electrocaloric cooling, and electrostrictive actuation. Several types of polarizations can be utilized to enhance dielectric constant of polymer dielectrics. Polymers with permanent dipoles can be good candidates to achieve high dielectric constant and low loss properties because of their dipolar polarization. There are several situations of dipolar polarization for polar polymers with permanent dipoles, which depend on different dipole/domain structures. Our work focuses on the novel ferroelectric behavior of ferroelectric polymers. The mechanism for novel ferroelectric behavior can be explained by the crystal pinning effect from crystal isomorphism. The physical pinning effect in P(VDF-TrFE-CFE) is weak and double hysteresis loop (DHL) is thus observed. The chemical pinning effect in e-beam P(VDF-TrFE) or P(VDF-TrFE-CTFE) is strong and only single hysteresis loop (SHL) is observed. Besides P(VDF-TrFE-CTFE), DHLs can also be achieved in P(VDF-TrFE-TrFE)-g-PS graft copolymer by the nanoconfined effect. Crystal orientation and temperature effects on the DHL behavior of the graft copolymer were studied. Clear dielectric, rather than ferroelectric, behavior is observed from the non-oriented graft polymer sample. But stable DHLs are observed for the oriented films up to 75 C. Above 100 C, huge broadening of the D-E loops shows up due to the electrical conduction and ion migrational losses. The electrical conduction loss plays an important role on the insulation property of dielectric polymers, especially at high temperatures and under high electric fields. As an example, a commercial biaxially oriented PVDF (BOPVDF) film was selected to study the electrical conduction under different electric poling conditions. The dipoles from either amorphous or crystalline phase do not have much influence on the electronic conduction. The electronic conductivity for the BOPVDF film is low below 25 C. Above 25 C, the electronic conductivity first increases, then decreases upon increasing the poling fields. These changes can be attributed to the effect from polarized ions. Above 75 C, electronic conductivity substantially increase due to injected space charges. Meanwhile, PVDF starts to undergo electrochemical reactions, emitting HF gas which can corrode metal electrodes.
