Download or read book Relaxation Behaviour of Patterned Composite Polymer Surfaces and Underlying Compensation Phenomenon written by Sonal Bhadauriya and published by . This book was released on 2019 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Imprinted polymer and polymer nanocomposite surfaces are ubiquitous in nature but how do such surfaces relax? What underlying fundamental mechanism governs the relaxation behaviour of such films? These are some of the pressing questions in the realm of flexible electronics, advanced lithography, nanodevices and biosensors where a decay in the stability of imprinted nanostructures can render them unusable. Therefore, tuning the stability of imprinted features in polymer thin films presents an important problem from both fundamental and application standpoint. The stability of imprinted nanostructures in homopolymer thin films has been extensively studied, using both ex-situ and in-situ procedures where the structural decay is governed by Laplace pressure induced viscous flow. Imprinted polymer nanocomposite films are ubiquitously present; from laminates to drag reducing coatings but the effect of additives in imparting structural stability is essentially unexplored.In the first section of this study, the nano-structure decay (also called "slumping") in imprinted PMMA thin films (≈ 100 nm) containing clustered PMMA grafted titania nanoparticles (TiO2 PGNP) and well-dispersed PMMA grafted Silica nanoparticles (SiO2 PGNP) was investigated. It was demonstrated that the stability of the nanoimprinted pattern at temperature above the matrix's glass transition temperature can be tuned by addition of these nanoparticles to the polymer matrix. This is the first experimental investigation of structural decay of a patterned nanocomposite film and it sheds light on an underlying entropy-enthalpy compensation (EEC) behaviour governing the decay process. EEC signifies a linear dependence between the activation parameters of the relaxation process and is routinely observed in the dynamics of many condensed materials such as molecular additives and glass-forming materials. Herein we found relaxation behaviour of nanoparticle filled imprinted polymer films illustrating similar compensation effect, which lead to slower decay kinetics of nanocomposite thin film above a certain compensation temperature compared to the neat polymer film. This characteristic temperature is conventionally called the entropy−enthalpy compensation (EEC) temperature, Tcomp and it was found to be ≈ 92 (±5) °C for TiO2 PGNP and 91 (±3) °C for SiO2 PGNP, a temperature in the vicinity of the matrix Tg ≈ 97 °C. An important implication of the compensation behaviour is that the stabilizing effect of the PGNP on the imprinted patterns should no longer exists if the slumping temperature is lower than Tcomp. It was seen that the filled imprinted pattern slumps more rapidly compared to the pure PMMA film at 80 °C (T
Download or read book Relaxation Phenomena written by Wolfgang Haase and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe the electric, magnetic and other relaxational processes in a wide spectrum of materials: liquid crystals, molecular magnets, polymers, high-Tc superconductors and glasses. The book summarizes the phenomenological fundamentals and the experimental methods used. A detailed description of molecular and collective dynamics in the broad range of liquid crystals is presented. Magnetic systems, high-Tc superconductors, polymers and glasses are an important subject of matter. It is shown that the researchers working on relaxation processes in different fields of materials sciences are dealing with the same physical fundamentals, but are sometimes using slightly different terms. The book is addressed to scientists, engineers, graduate and undergraduate students, experimentalists and theorists in physics, chemistry, materials sciences and electronic engineering. Many internationally well known experts contribute to it.
Download or read book Liquid Crystals and Display Technology written by Morteza Sasani Ghamsari and published by BoD – Books on Demand. This book was released on 2020-10-07 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystals have attracted scientific attention for potential applications in advanced devices. Display technology is continuously growing and expanding and, as such, this book provides an overview of the most recent advances in liquid crystals and displays. Chapters cover such topics as nematic liquid crystals, active matrix organic light-emitting diodes, and tetradentate platinum(II) emitters, among others.
Download or read book Engineered Interfaces in Fiber Reinforced Composites written by Jang-Kyo Kim and published by Elsevier. This book was released on 1998-10-21 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study and application of composite materials are a truly interdisciplinary endeavour that has been enriched by contributions from chemistry, physics, materials science, mechanics and manufacturing engineering. The understanding of the interface (or interphase) in composites is the central point of this interdisciplinary effort. From the early development of composite materials of various nature, the optimization of the interface has been of major importance. While there are many reference books available on composite materials, few of them deal specifically with the science and mechanics of the interface of fiber reinforced composites. Further, many recent advances devoted solely to research in composite interfaces have been scattered in a variety of published literature and have yet to be assembled in a readily accessible form. To this end this book is an attempt to bring together recent developments in the field, both from the materials science and mechanics perspective, in a single convenient volume.The central theme of the book is tailoring the interface properties to optimise the mechanical peformance and structural integrity of composites with enhanced strength/stiffness and fracture toughness (or specific fracture resistance). It deals mainly with interfaces in advanced composites made from high performance fibers, such as glass, carbon, aramid, ultra high modulus polyethylene and some inorganic (e.g. B/W, A12O3, SiC) fibers, and matrix materials encompassing polymers, metals/alloys and ceramics. The book is intended to provide a comprehensive treatment of composite interfaces in such a way that it should be of interest to materials scientists, technologists and practising engineers, as well as graduate students and their supervisors in advanced composites. We hope that this book will also serve as a valuable source of reference to all those involved in the design and research of composite interfaces.The book contains eight chapters of discussions on microstructure-property relationships with underlying fundamental mechanics principles. In Chapter 1, an introduction is given to the nature and definition of interfaces in fiber reinforced composites. Chapter 2 is devoted to the mechanisms of adhesion which are specific to each fiber-matrix system, and the physio-chemical characterization of the interface with regard to the origin of adhesion. The experimental techniques that have been developed to assess the fiber-matrix interface bond quality on a microscopic scale are presented in Chapter 3, along with the techniques of measuring interlaminar/intralaminar strengths and fracture toughness using bulk composite laminates. The applicability and limitations associated with loading geometry and interpretation of test data are compared. Chapter 4 presents comprehensive theoretical analyses based on shear-lag models of the single fiber composite tests, with particular interest being placed on the interface debond process and the nature of the fiber-matrix interfacial bonding. Chapter 5 is devoted to reviewing current techniques of fiber surface treatments which have been devised to improve the bond strength and the fiber-matrix compatibility/stability during the manufacturing processes of composites. The micro-failure mechanisms and their associated theories of fracture toughness of composites are discussed in Chapter 6. The roles of the interface and its effects on the mechanical performance of fiber composites are addressed from several viewpoints. Recent research efforts to augment the transverse and interlaminar fracture toughness by means of controlled interfaces are presented in Chapters 7 and 8.
Download or read book The Glossary of Prosthodontic Terms written by and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Polymer Composite Materials written by Nicolas Boyard and published by John Wiley & Sons. This book was released on 2016-03-28 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses general information, good practices and examples about thermo-physical properties, thermo-kinetic and thermo-mechanical couplings, instrumentation in thermal science, thermal optimization and infrared radiation.
Download or read book Polymer Nanocomposites written by Aravind Dasari and published by Springer. This book was released on 2016-06-28 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highlights ongoing research efforts on different aspects of polymer nanocomposites and explores their potentials to exhibit multi-functional properties. In this context, it addresses both fundamental and advanced concepts, while delineating the parameters and mechanisms responsible for these potentials. Aspects considered include embrittlement/toughness; wear/scratch behaviour; thermal stability and flame retardancy; barrier, electrical and thermal conductivity; and optical and magnetic properties. Further, the book was written as a coherent unit rather than a collection of chapters on different topics. As such, the results, analyses and discussions presented herein provide a guide for the development of a new class of multi-functional nanocomposites. Offering an invaluable resource for materials researchers and postgraduate students in the polymer composites field, they will also greatly benefit materials
Download or read book Polymer Tribology written by Sujeet K. Sinha and published by World Scientific. This book was released on 2009 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the new and now-expanding field of friction, wear, and other surface-related mechanical phenomena for polymers. Polymers have been used in various forms such as bulk, films, and composites in applications where their friction, wear resistance, and other surface-related properties have been effectively utilized. There are also many examples in which polymers have performed extremely well, such as in tyres, shoes, brakes, gears, bearings, small moving parts in electronics and MEMS, cosmetics/hair products, and artificial human joints. Around the world, much research is currently being undertaken to develop new polymers, in different forms, for further enhancing tribological performance and for finding novel applications. Keeping in view the importance of tribology of polymers for research and technology as well as the vast literature that is now available in research papers and review articles, this timely book brings together a wealth of research data for an understanding of the basic principles of the subject.
Download or read book Properties of Polymers written by D.W. van Krevelen and published by Elsevier. This book was released on 2012-12-02 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions summarizes the latest developments regarding polymers, their properties in relation to chemical structure, and methods for estimating and predicting numerical properties from chemical structure. In particular, it examines polymer electrical properties, magnetic properties, and mechanical properties, as well as their crystallization and environmental behavior and failure. The rheological properties of polymer melts and polymer solutions are also considered. Organized into seven parts encompassing 27 chapters, this book begins with an overview of polymer science and engineering, including the typology of polymers and their properties. It then turns to a discussion of thermophysical properties, from transition temperatures to volumetric and calorimetric properties, along with the cohesive aspects and conformation statistics. It also introduces the reader to the behavior of polymers in electromagnetic and mechanical fields of force. The book covers the quantities that influence the transport of heat, momentum, and matter, particularly heat conductivity, viscosity, and diffusivity; properties that control the chemical stability and breakdown of polymers; and polymer properties as an integral concept, with emphasis on processing and product properties. Readers will find tables that give valuable (numerical) data on polymers and include a survey of the group contributions (increments) of almost every additive function considered. This book is a valuable resource for anyone working on practical problems in the field of polymers, including organic chemists, chemical engineers, polymer processers, polymer technologists, and both graduate and PhD students.
Download or read book Polymer Chemistry written by Timothy P. Lodge and published by CRC Press. This book was released on 2020-07-14 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: A well-rounded and articulate examination of polymer properties at the molecular level, Polymer Chemistry focuses on fundamental principles based on underlying chemical structures, polymer synthesis, characterization, and properties. It emphasizes the logical progression of concepts and provide mathematical tools as needed as well as fully derived problems for advanced calculations. The much-anticipated Third Edition expands and reorganizes material to better develop polymer chemistry concepts and update the remaining chapters. New examples and problems are also featured throughout. This revised edition: Integrates concepts from physics, biology, materials science, chemical engineering, and statistics as needed Contains mathematical tools and step-by-step derivations for example problems Incorporates new theories and experiments using the latest tools and instrumentation and topics that appear prominently in current polymer science journals The number of homework problems has been greatly increased, to over 350 in all The worked examples and figures have been augmented More examples of relevant synthetic chemistry have been introduced into Chapter 2 ("Step-Growth Polymers") More details about atom-transfer radical polymerization and reversible addition/fragmentation chain-transfer polymerization have been added to Chapter 4 ("Controlled Polymerization") Chapter 7 (renamed "Thermodynamics of Polymer Mixtures") now features a separate section on thermodynamics of polymer blends Chapter 8 (still called "Light Scattering by Polymer Solutions") has been supplemented with an extensive introduction to small-angle neutron scattering Polymer Chemistry, Third Edition offers a logical presentation of topics that can be scaled to meet the needs of introductory as well as more advanced courses in chemistry, materials science, polymer science, and chemical engineering.
Download or read book Creep and Fatigue in Polymer Matrix Composites written by Rui Miranda Guedes and published by Woodhead Publishing. This book was released on 2019-03-14 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creep and Fatigue in Polymer Matrix Composites, Second Edition, updates the latest research in modeling and predicting creep and fatigue in polymer matrix composites. The first part of the book reviews the modeling of viscoelastic and viscoplastic behavior as a way of predicting performance and service life. Final sections discuss techniques for modeling creep rupture and failure and how to test and predict long-term creep and fatigue in polymer matrix composites. - Reviews the latest research in modeling and predicting creep and fatigue in polymer matrix composites - Puts a specific focus on viscoelastic and viscoplastic modeling - Features the time-temperature-age superposition principle for predicting long-term response - Examines the creep rupture and damage interaction, with a particular focus on time-dependent failure criteria for the lifetime prediction of polymer matrix composite structures that are illustrated using experimental cases
Download or read book The Materials Science of Thin Films written by Milton Ohring and published by Academic Press. This book was released on 1992 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared as a textbook complete with problems after each chapter, specifically intended for classroom use in universities.
Download or read book Polymer Matrix Composites and Technology written by Ru-Min Wang and published by Elsevier. This book was released on 2011-07-14 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given such properties as low density and high strength, polymer matrix composites have become a widely used material in the aerospace and other industries. Polymer matrix composites and technology provides a helpful overview of these materials, their processing and performance.After an introductory chapter, part one reviews the main reinforcement and matrix materials used as well as the nature of the interface between them. Part two discusses forming and molding technologies for polymer matrix composites. The final part of the book covers key aspects of performance, including tensile, compression, shear and bending properties as well as impact, fatigue and creep behaviour.Polymer matrix composites and technology provides both students and those in industry with a valuable introduction to and overview of this important class of materials. - Provides a helpful overview of these materials, their processing and performance incorporating naming and classification of composite materials - Reviews the main reinforcement and matrix materials used as well as the nature of the interface between them including damage mechanisms - Discusses forming and molding technologies for polymer matrix composites outlining various techniques and technologies
Download or read book Strengthening Forensic Science in the United States written by National Research Council and published by National Academies Press. This book was released on 2009-07-29 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scores of talented and dedicated people serve the forensic science community, performing vitally important work. However, they are often constrained by lack of adequate resources, sound policies, and national support. It is clear that change and advancements, both systematic and scientific, are needed in a number of forensic science disciplines to ensure the reliability of work, establish enforceable standards, and promote best practices with consistent application. Strengthening Forensic Science in the United States: A Path Forward provides a detailed plan for addressing these needs and suggests the creation of a new government entity, the National Institute of Forensic Science, to establish and enforce standards within the forensic science community. The benefits of improving and regulating the forensic science disciplines are clear: assisting law enforcement officials, enhancing homeland security, and reducing the risk of wrongful conviction and exoneration. Strengthening Forensic Science in the United States gives a full account of what is needed to advance the forensic science disciplines, including upgrading of systems and organizational structures, better training, widespread adoption of uniform and enforceable best practices, and mandatory certification and accreditation programs. While this book provides an essential call-to-action for congress and policy makers, it also serves as a vital tool for law enforcement agencies, criminal prosecutors and attorneys, and forensic science educators.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1994 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clay Polymer Nanocomposites written by Khouloud Jlassi and published by Elsevier. This book was released on 2017-07-26 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay–Polymer Nanocomposites is a complete summary of the existing knowledge on this topic, from the basic concepts of synthesis and design to their applications in timely topics such as high-performance composites, environment, and energy issues. This book covers many aspects of synthesis such as in- situ polymerization within the interlamellar spacing of the clays or by reaction of pristine or pre-modified clays with reactive polymers and prepolymers. Indeed, nanocomposites can be prepared at industrial scale by melt mixing. Regardless the synthesis method, much is said in this book about the importance of theclay pre-modification step, which is demonstrated to be effective, on many occasions, in obtaining exfoliated nanocomposites. Clay–Polymer Nanocomposites reports the background to numerous characterization methods including solid state NMR, neutron scattering, diffraction and vibrational techniques as well as surface analytical methods, namely XPS, inverse gas chromatography and nitrogen adsorption to probe surface composition, wetting and textural/structural properties. Although not described in dedicated chapters, numerous X-ray diffraction patterns of clay–polymer nanocomposites and reference materials are displayed to account for the effects of intercalation and exfoliations of layered aluminosilicates. Finally, multiscale molecular simulation protocols are presenting for predicting morphologies and properties of nanostructured polymer systems with industrial relevance. As far as applications are concerned, Clay–Polymer Nanocomposites examines structural composites such as clay–epoxy and clay–biopolymers, the use of clay–polymer nanocomposites as reactive nanocomposite fillers, catalytic clay-(conductive) polymers and similar nanocomposites for the uptake of hazardous compounds or for controlled drug release, antibacterial applications, energy storage, and more. - The most comprehensive coverage of the state of the art in clay–polymer nanocomposites, from synthesis and design to opportunities and applications - Covers the various methods of characterization of clay–polymer nanocomposites - including spectroscopy, thermal analyses, and X-ray diffraction - Includes a discussion of a range of application areas, including biomedicine, energy storage, biofouling resistance, and more
Download or read book Broadband Dielectric Spectroscopy written by Friedrich Kremer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both an introductory course to broadband dielectric spectroscopy and a monograph describing recent dielectric contributions to current topics, this book is the first to cover the topic and has been hotly awaited by the scientific community.
