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 Processing Structure and Ferroelectric Properties of PVDF based Ferroelectric Polymers written by Nan Meng and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Ferroelectric Polymers written by Hari Singh Nalwa and published by CRC Press. This book was released on 1995-06-20 with total page 904 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 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 Polymers written by E. Fukada and published by CRC Press. This book was released on 1989 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains four papers commencing with an introduction to early studies in piezoelectricity, pyroelectricity and ferroelectricity in polymers. Other topics discussed include - ferroelectric properties of fluoride copolymers; structural phase transition in ferroelectric fluorine polymers; and pressure effect on phase transition in ferroelectric polymers .

Download or read book Piezoelectric Energy Harvesting written by Alper Erturk and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transformation of vibrations into electric energy through the use of piezoelectric devices is an exciting and rapidly developing area of research with a widening range of applications constantly materialising. With Piezoelectric Energy Harvesting, world-leading researchers provide a timely and comprehensive coverage of the electromechanical modelling and applications of piezoelectric energy harvesters. They present principal modelling approaches, synthesizing fundamental material related to mechanical, aerospace, civil, electrical and materials engineering disciplines for vibration-based energy harvesting using piezoelectric transduction. Piezoelectric Energy Harvesting provides the first comprehensive treatment of distributed-parameter electromechanical modelling for piezoelectric energy harvesting with extensive case studies including experimental validations, and is the first book to address modelling of various forms of excitation in piezoelectric energy harvesting, ranging from airflow excitation to moving loads, thus ensuring its relevance to engineers in fields as disparate as aerospace engineering and civil engineering. Coverage includes: Analytical and approximate analytical distributed-parameter electromechanical models with illustrative theoretical case studies as well as extensive experimental validations Several problems of piezoelectric energy harvesting ranging from simple harmonic excitation to random vibrations Details of introducing and modelling piezoelectric coupling for various problems Modelling and exploiting nonlinear dynamics for performance enhancement, supported with experimental verifications Applications ranging from moving load excitation of slender bridges to airflow excitation of aeroelastic sections A review of standard nonlinear energy harvesting circuits with modelling aspects.

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 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 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 Ferroelectric Polymer PVDF Based Nanogenerator written by Jeongjae Ryu and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter deals with the development of ferroelectric polymer polyvinylidene fluoride (PVDF)-based nanogenerators. Due to its inherent flexibility, PVDF has been studied for application in nanogenerators. We first introduce PVDF and its copolymers, and briefly discuss their properties. Then, we discuss fabrication methods, including solution casting, spin coating, template-assisted method, electrospinning, thermal drawing, and dip coating. Using these methods, a wide variety of ferroelectric polymer structures can be fabricated. In addition to the performance enhancements provided by fabrication methods, the performance of PVDF-based nanogenerators has been improved by incorporating fillers that can alter the factors affecting the performance. Next, we review energy sources that can be exploited by PVDF-based nanogenerators to harvest electricity. The abundant energy sources in the environment include sound, wind flow, and thermal fluctuation. Finally, we discuss implantable PVDF-based nanogenerators. Another advantage of PVDF is its biocompatibility, which enables implantable nanogenerators. We believe that this chapter can also be helpful to researchers who study sensors and actuators as well as nanogenerators.

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 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 205 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.

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 Ferroelectric Gate Field Effect Transistor Memories written by Byung-Eun Park and published by Springer Nature. This book was released on 2020-03-23 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive coverage of the materials characteristics, process technologies, and device operations for memory field-effect transistors employing inorganic or organic ferroelectric thin films. This transistor-type ferroelectric memory has interesting fundamental device physics and potentially large industrial impact. Among various applications of ferroelectric thin films, the development of nonvolatile ferroelectric random access memory (FeRAM) has been most actively progressed since the late 1980s and reached modest mass production for specific application since 1995. There are two types of memory cells in ferroelectric nonvolatile memories. One is the capacitor-type FeRAM and the other is the field-effect transistor (FET)-type FeRAM. Although the FET-type FeRAM claims the ultimate scalability and nondestructive readout characteristics, the capacitor-type FeRAMs have been the main interest for the major semiconductor memory companies, because the ferroelectric FET has fatal handicaps of cross-talk for random accessibility and short retention time. This book aims to provide the readers with development history, technical issues, fabrication methodologies, and promising applications of FET-type ferroelectric memory devices, presenting a comprehensive review of past, present, and future technologies. The topics discussed will lead to further advances in large-area electronics implemented on glass, plastic or paper substrates as well as in conventional Si electronics. The book is composed of chapters written by leading researchers in ferroelectric materials and related device technologies, including oxide and organic ferroelectric thin films.