Download or read book Experimental Investigation on Ferroelectric and Flexoelectric Properties of Poly vinylidenefluoride hexafluoropropylene PVDF HFP Copolymer Films written by Ho Joon Lee and published by . This book was released on 2010 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electric polarization induced by the non-uniform deformation, i.e. the direct flexoelectric effect, in poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) has been investigated. The ferroelectric properties of PVDF-HFP copolymer films were measured. The primary goal of the research in this thesis is to understand the properties of both ferroelectricity and flexoelectricity of PVDF-HFP copolymer films under different circumstances. It is well known that PVDF homo polymer mainly has three phase structures, α phase (TGTG'), β phase (TTTT), and γ phase (TTTGTTTG'), depending on the chain conformations as the trans (T) or the gauche (G) linkages. Only β phase and γ phase possess piezoelectric responses. The direct flexoelectric effect can exist in any phase. This is because the inhomogeneous deformation can break the inversion symmetry and induce electric polarization even in non-piezoelectric crystalline materials.^However, in PVDF-HFP copolymer, the molecular chain conformations of PVDF are modified by HFP monomers. Although the mixture of two polymers can be regarded as a random amorphous structure, their molecular chain conformations may splay to different directions if a non-uniform deformation is applied to them. Therefore both ferroelectric and flexoelectric properties of PVDF-HFP copolymers might be significantly different from that of PVDF homo polymers. In our experimental studies, the unaligned PVDF-HFP copolymer films were initially synthesized by using the solution polymerization process and then characterized via X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). The flexoelectric coefficients of those polymer films were then measured. Both the enhanced direct flexoelectric effect and the ferroelectric-like behavior were observed in the polymer films.^However, the flexoelectric coefficient of PVDF-HFP copolymers we measured is almost 50% smaller than that of the unaligned PVDF homo films. The experimental results also demonstrate that the ferroelectric-like behavior in PVDF-HFP copolymers under different conditions might be induced by their spatially distributed space electric charges. The measured flexoelectric coefficient (μ13) and the piezoelectric coefficient (d13) can also give us valuable information about the property degradation, or aging phenomena, in polymer films and the related polymer devices.
Download or read book Flexoelectric and Ferroelectric Properties of Quenched Polyvinylidene Fluoride PVDF Homopolymer Films written by Sankar Thiruvannamalai and published by . This book was released on 2010 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flexoelectric and ferroelectric properties of quenched polyvinylidene fluoride (PVDF) homopolymer films have been investigated in this thesis. It is well known that PVDF homopolymer mainly has three phase structures, alpha phase (TGTG'), beta phase (TTTT), and gamma phase (TTTGTTTG'), depending on the chain conformations as the trans (T) or the gauche (G) linkages. However, the quenched PVDF homopolymer has different molecular chain conformations, which may render some unique mechanical and electric properties. Quenching is a mechanical process in which PVDF homopolymer is strengthened and hardened. This is done by heating PVDF solution at a certain temperature, where the polymerization cannot be formed, then rapidly cooling the polymer; in annealing process, only in certain local microscopic areas, polymerization can occur to let PVDF monomer molecules aggregate together to form the alpha, beta, and gamma phases.^So the regions between those areas in the polymer have amorphous structures. Thus, the piezoelectric behavior of the quenched PVDF homopolymer might be altered since only beta phase and gamma phase in PVDF possess piezoelectric responses and the volume, in which both beta phase and gamma phase exist, in the quenched polymer is reduced. However, whether the direct flexoelectric effect is influenced or not in the quenched PVDF homopolymer is still unknown. This is because the direct flexoelectric effect can exist in polymers of any phase; the inhomogeneous deformation can break the inversion symmetry and induce electric polarization even in non-piezoelectric phase. In our experimental studies, the quenched PVDF homopolymer films were initially synthesized using solution polymerization process and then were quenched in ice-water. We further characterized our samples by using X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM).^The flexoelectric coefficients of those polymer films were then measured. Both the enhanced direct flexoelectric effect and the ferroelectric-like behavior were observed in the quenched polymer films. Our studies have shown that both the effect and the behavior largely depend on the molecular chain configurations of the quenched PVDF films. Our experimental results also demonstrate that the ferroelectric-like behavior in the quenched PVDF film might be induced by its spatially distributed space electric charges. The measured flexoelectric coefficient (mu13) may also give us valuable information about how aging phenomena would be induced in polymer films.
Download or read book Experimental Studies of Flexoelectricity in Polyvinylidene Fluoride PVDF Homopolyner Films written by Hyun Heo and published by . This book was released on 2010 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electric polarization induced by the non-uniform deformation, i.e. the direct flexoelectric effect, in polyvinylidene fluoride (PVDF) has been investigated based on a beam bending method in this thesis. The primary goal of my research is to understand the properties of both ferroelectricity and flexoelectricity of PVDF homopolymer films under the unaligned state. Generally speaking, bulk PVDF materials exists in three phase structures, α phase (TGTG'), β phase (TTTT), and γ phase (TTTGTTTG'), depending on the chain conformations as the trans (T) or the gauche (G) linkages. Only β phase and γ phase possess piezoelectric responses; however the direct flexoelectric effect can exist in any phase. This is because the inhomogeneous deformation can break the inversion symmetry and induce electric polarization even in non-piezoelectric crystalline materials.^In my experimental study, the unaligned PVDF homopolymer films were initially synthesized using solution polymerization process and then characterized by using X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). The flexoelectric coefficients of those polymer films were then measured. Both the enhanced direct flexoelectric effect and the ferroelectric-like behavior were observed in the polymer films. My studies have shown that both the effect and the behavior largely depend on the molecular chain configuration of PVDF films. Compared with certain aligned PVDF films, the flexoelectric properties of the unaligned PVDF film could be significantly different. My experimental results also demonstrate that the ferroelectric-like behavior in the unaligned PVDF film might be induced by its spatially distributed space electric charges.^The measured flexoelectric coefficient (μ13) and the piezoelectric coefficient (d13) can also give us valuable information about the property degradation, or aging phenomena, in polymer films and the related polymer devices. Finally I summarize my research and discuss some possible future research topics which could follow my thesis.
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 Electromechanically Active Polymers written by Federico Carpi and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptronics and Smart Structures written by Hartmut Janocha and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptronics is the term encompassing technical fields that have become known internationally under the names "smart materials", "intelligent structures", and "smart structures". Adaptronics contributes to the optimisation of systems and products. It bridges the gap between material and system or product, and incorporates the search for multi-functional materials and elements and their integration in systems or structures. The authors of this book have taken on the task of displaying the current state of the art in this fascinating field. The system components, actuators, sensors and controllers, technical fundamentals, materials, design rules and practical solutions are all described. Selected sample applications are also presented and current development trends are demonstrated.
Download or read book Soft Actuators written by Kinji Asaka and published by Springer Nature. This book was released on 2019-08-28 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the second edition of Soft Actuators, originally published in 2014, with 12 chapters added to the first edition. The subject of this new edition is current comprehensive research and development of soft actuators, covering interdisciplinary study of materials science, mechanics, electronics, robotics, and bioscience. The book includes contemporary research of actuators based on biomaterials for their potential in future artificial muscle technology. Readers will find detailed and useful information about materials, methods of synthesis, fabrication, and measurements to study soft actuators. Additionally, the topics of materials, modeling, and applications not only promote the further research and development of soft actuators, but bring benefits for utilization and industrialization. This volume makes generous use of color figures, diagrams, and photographs that provide easy-to-understand descriptions of the mechanisms, apparatus, and motions of soft actuators. Also, in this second edition the chapters on modeling, materials design, and device design have been given a wider scope and made easier to comprehend, which will be helpful in practical applications of soft actuators. Readers of this work can acquire the newest technology and information about basic science and practical applications of flexible, lightweight, and noiseless soft actuators, which differ from conventional mechanical engines and electric motors. This new edition of Soft Actuators will inspire readers with fresh ideas and encourage their research and development, thus opening up a new field of applications for the utilization and industrialization of soft actuators.
Download or read book Innovation in Electrical Power Engineering Communication and Computing Technology written by Manohar Mishra and published by Springer Nature. This book was released on 2021-12-15 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book features selected high-quality papers from the Second International Conference on Innovation in Electrical Power Engineering, Communication, and Computing Technology (IEPCCT 2021), held at Siksha 'O' Anusandhan (Deemed to be University), Bhubaneswar, India, on 24–26 September 2021. Presenting innovations in power, communication, and computing, it covers topics such as mini, micro, smart and future power grids; power system economics; energy storage systems; intelligent control; power converters; improving power quality; signal processing; sensors and actuators; image/video processing; high-performance data mining algorithms; advances in deep learning; and optimization methods.
Download or read book Composites and Their Applications written by Ning Hu and published by IntechOpen. This book was released on 2012-08-22 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composites are a class of material, which receives much attention not only because it is on the cutting edge of active material research fields due to appearance of many new types of composites, e.g., nanocomposites and bio-medical composites, but also because there are a great deal of promise for its potential applications in various industries ranging from aerospace to construction due to its various outstanding properties. This book mainly describes some potential applications and the related properties of various composites by focusing on the following several topics: health or integrity monitoring techniques of composites structures, bio-medical composites and their applications in dental or tissue materials, natural fiber or mineral filler reinforced composites and their property characterization, catalysts composites and their applications, and some other potential applications of fibers or composites as sensors, etc. This book has been divided into five sections to cover the above contents.
Download or read book Electroactive Polymers for Robotic Applications written by Kwang J. Kim and published by Springer Science & Business Media. This book was released on 2007-01-17 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the fundamental properties, modeling, and demonstration of Electroactive polymers in robotic applications. It particularly details artificial muscles and sensors. In addition, the book discusses the properties and uses in robotics applications of ionic polymer–metal composite actuators and dielectric elastomers.
Download or read book The Beginnings of Piezoelectricity written by Shaul Katzir and published by Springer Science & Business Media. This book was released on 2007-04-08 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Beginnings of Piezoelectricity, the first history of the subject, exhaustively examines how diverse influences led to the discovery of the phenomenon in 1880, and how they shaped subsequent research until the consolidation of an empirical and theoretical knowledge of the field circa 1895. Shaul Katzir’s historical account shows that this ‘mundane’ science was an intriguing intellectual and practical enterprise, which involved originality, surprises and controversies.
Download or read book Second Contacts written by Hayden Trenholm and published by Bundoran Press Publishing. This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Second Contacts "presents eighteen stories from writers in six countries (Canada, United States, England, Mexico, Israel, and the Netherlands) that answer the question: What happens after first contact? Set fifty years in the future, they explore the aftermath of alien contact, for us and for the aliens.
Download or read book Dielectric Ceramics written by K. M. Nair and published by . This book was released on 1993 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dielectric Properties of Binary Solutions written by Y. Y. Akhadov and published by Elsevier. This book was released on 2013-10-22 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dielectric Properties of Binary Solutions focuses on the investigation of the dielectric properties of solutions, as well as the molecular interactions and mechanisms of molecular processes that occur in liquids. The book first discusses the fundamental formulas describing the dielectric properties of liquids and dielectric data for binary systems of non-aqueous solutions. Topics include permittivity and dielectric dispersion parameters of non-aqueous solutions of organic and inorganic compounds. The text also tackles dielectric data for binary systems of aqueous solutions, including permittivity of aqueous solutions of organic and inorganic compounds and dielectric dispersion parameters of aqueous solutions of organic and inorganic compounds. The tables that show the measurements of static permittivity, limiting high-frequency permittivity, permittivity and dielectric loss, relaxation time, and coefficient of distribution of relaxation times are presented. The manuscript also presents dielectric data in graphical form. The book is a vital reference for readers interested in the dielectric properties of binary solutions.
Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.
Download or read book Electrical Properties of Polymers written by A. R. Blythe and published by Cambridge University Press. This book was released on 2005-06-10 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive update on the fundamentals and recent advancements of electrical properties of polymers.
Download or read book Technology of Fluoropolymers written by Jiri George Drobny and published by CRC Press. This book was released on 2008-09-19 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully revised and updated, this second edition continues to provide industrial chemists, technologists, and engineers with the most accurate, compact, and practical source on fluoropolymers (such as Teflon). Highlighting new industrial, military, medical, and consumer goods applications, this edition adds more detailed information on equipment and
