Download or read book Molecular Dynamics Simulations of Spinodal Assisted Polymer Crystallization written by R. H. Gee and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large scale molecular dynamics simulations of bulk melts of polar (poly(vinylidene fluoride) (pVDF)) polymers are utilized to study chain conformation and ordering prior to crystallization under cooling. While the late stages of polymer crystallization have been studied in great detail, recent theoretical and experimental evidence indicates that there are important phenomena occurring in the early stages of polymer crystallization that are not understood to the same degree. When the polymer melt is quenched from a temperature above the melting temperature to the crystallization temperature, crystallization does not occur instantaneously. This initial interval without crystalline order is characterized as an induction period. It has been thought of as a nucleation period in the classical theories of polymer crystallization, but recent experiments, computer simulations, and theoretical work suggest that the initial period in polymer crystallization is assisted by a spinodal decomposition type mechanism. In this study we have achieved physically realistic length scales to study early stages of polymer ordering, and show that spinodal-assisted ordering prior to crystallization is operative in polar polymers suggesting general applicability of this process.
Download or read book Advances in Computational Methods in Sciences and Engineering 2005 2 vols written by Theodore Simos and published by CRC Press. This book was released on 2022-05-05 with total page 1056 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together selected contributed papers presented at the International Conference of Computational Methods in Science and Engineering (ICCMSE 2005), held in Greece, 21 aEURO" 26 October 2005. The conference aims to bring together computational scientists from several disciplines in order to share methods and ideas. The ICCMSE is unique in its kind. It regroups original contributions from all fields of the traditional Sciences, Mathematics, Physics, Chemistry, Biology, Medicine and all branches of Engineering. It would be perhaps more appropriate to define the ICCMSE as a conference on computational science and its applications to science and engineering. Topics of general interest are: Computational Mathematics, Theoretical Physics and Theoretical Chemistry. Computational Engineering and Mechanics, Computational Biology and Medicine, Computational Geosciences and Meteorology, Computational Economics and Finance, Scientific Computation. High Performance Computing, Parallel and Distributed Computing, Visualization, Problem Solving Environments, Numerical Algorithms, Modelling and Simulation of Complex System, Web-based Simulation and Computing, Grid-based Simulation and Computing, Fuzzy Logic, Hybrid Computational Methods, Data Mining, Information Retrieval and Virtual Reality, Reliable Computing, Image Processing, Computational Science and Education etc. More than 800 extended abstracts have been submitted for consideration for presentation in ICCMSE 2005. From these 500 have been selected after international peer review by at least two independent reviewers.
Download or read book Molecular Technology Volume 3 written by Hisashi Yamamoto and published by John Wiley & Sons. This book was released on 2019-08-05 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by foremost leaders in chemical research together with a number of distinguished international authors, this third volume summarizes the most important and promising recent developments in material science in one book. Interdisciplinary and application-oriented, this ready reference focuses on innovative methods, covering new developments in photofunctional materials, polymer chemistry, surface science and more. Of great interest to chemists as well as material scientists alike.
Download or read book Nucleation in Condensed Matter written by Ken Kelton and published by Elsevier. This book was released on 2010-03-19 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Nucleation in Condensed Matter, key theoretical models for nucleation are developed and experimental data are used to discuss their range of validity. A central aim of this book is to enable the reader, when faced with a phenomenon in which nucleation appears to play a role, to determine whether nucleation is indeed important and to develop a quantitative and predictive description of the nucleation behavior. The third section of the book examines nucleation processes in practical situations, ranging from solid state precipitation to nucleation in biological systems to nucleation in food and drink. Nucleation in Condensed Matter is a key reference for an advanced materials course in phase transformations. It is also an essential reference for researchers in the field. Unified treatment of key theories, experimental evaluations and case studies Complete derivation of key models Detailed discussion of experimental measurements Examples of nucleation in diverse systems
Download or read book Interphases and Mesophases in Polymer Crystallization III written by Giuseppe Allegra and published by Springer Science & Business Media. This book was released on 2005-12-02 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts
Download or read book Glass written by Jürn W. P. Schmelzer and published by Walter de Gruyter. This book was released on 2014-05-08 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: “This book contains overviews on technologically important classes of glasses, their treatment to achieve desired properties, theoretical approaches for the description of structure-property relationships, and new concepts in the theoretical treatment of crystallization in glass-forming systems. It contains overviews about the state of the art and about specific features for the analysis and application of important classes of glass-forming systems, and describes new developments in theoretical interpretation by well-known glass scientists. Thus, the book offers comprehensive and abundant information that is difficult to come by or has not yet been made public.” Edgar Dutra Zanotto (Center for Research, Technology and Education in Vitreous Materials, Brazil) Glass, written by a team of renowned researchers and experienced book authors in the field, presents general features of glasses and glass transitions. Different classes of glassforming systems, such as silicate glasses, metallic glasses, and polymers, are exemplified. In addition, the wide field of phase formation processes and their effect on glasses and their properties is studied both from a theoretical and experimental point of view.
Download or read book Molecular Dynamics Simulation of Uni and Bi modal Semicrystalline Polymers written by Zengqiang Zhai and published by . This book was released on 2019 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semicrystalline polymers (such as polyethylene, polylactic acid, polyamide, etc.) are used in a wide range of application (such as automotive, pipes, gearing, etc.) due to promoted mechanical properties. There is strong link between the mechanical properties and microstructure of semicrystalline polymer, such as bimodality, molecular topology (the way polymer chains pass through crystalline and amorphous phases), chain entanglements, lamellar thickness, temperature, and so on. However, these microstructure cannot be access quantitatively in experiment. There exists some molecular dynamics investigations, but the homogeneous crystallization is very difficult to achieve and not extensively discussed. Thus, the crystallization mechanism of polymers and the dependence of microstructure remain relatively unclear and controversy. In this thesis, we have performed the homogeneous crystallization of polymers using a coarse-grained molecular dynamics (CG-MD) model published in our previous article 1, which favors chain alignment and crystallization. The main objective of this thesis is to use CG-MD simulation technique to provide more insights of the homogeneous nucleation and crystal growth behavior of bimodal and unimodal MWD polymers, the influence of bimodality on the molecular topology (loop, tie, cilia) and entanglement concentration, the chain disentanglement process and its influence on lamellar thickening as well the temperature dependence.
Download or read book Ordered Polymeric Nanostructures at Surfaces written by G. Julius Vancso and published by Springer. This book was released on 2006-05-18 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts
Download or read book Controlling the Morphology of Polymers written by Geoffrey R. Mitchell and published by Springer. This book was released on 2016-09-06 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on controlling morphology of different scales for polymers. The authors explain the need for successful control of morphology to yield target macroscopic physical properties in the application of polymers to diverse areas such as engineering materials, nanodielectrics and photonic crystals. The book combines specialized chapters with an introduction to the morphology of polymers and the range of experimental techniques available to evaluate it.
Download or read book Polymer Morphology written by Qipeng Guo and published by John Wiley & Sons. This book was released on 2016-03-21 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a focus on structure-property relationships, this book describes how polymer morphology affects properties and how scientists can modify them. The book covers structure development, theory, simulation, and processing; and discusses a broad range of techniques and methods. • Provides an up-to-date, comprehensive introduction to the principles and practices of polymer morphology • Illustrates major structure types, such as semicrystalline morphology, surface-induced polymer crystallization, phase separation, self-assembly, deformation, and surface topography • Covers a variety of polymers, such as homopolymers, block copolymers, polymer thin films, polymer blends, and polymer nanocomposites • Discusses a broad range of advanced and novel techniques and methods, like x-ray diffraction, thermal analysis, and electron microscopy and their applications in the morphology of polymer materials
Download or read book Molecular Dynamics Simulations of Crystallization written by Papa Kofi Boateng and published by . This book was released on 1999 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Encyclopedia of Polymer Blends Volume 1 written by Avraam I. Isayev and published by John Wiley & Sons. This book was released on 2016-09-12 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and timely overview of the topic, this volume of the encyclopedia imparts knowledge of fundamental principles of polymer blends. Each article is uniformly structured for easy navigation, containing the latest research & development and its basic principles and applications.
Download or read book Surface Modification of Polymers written by Jean Pinson and published by John Wiley & Sons. This book was released on 2020-02-18 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to modifying and functionalizing the surfaces of polymers Surface Modification of Polymers is an essential guide to the myriad methods that can be employed to modify and functionalize the surfaces of polymers. The functionalization of polymer surfaces is often required for applications in sensors, membranes, medicinal devices, and others. The contributors?noted experts on the topic?describe the polymer surface in detail and discuss the internal and external factors that influence surface properties. This comprehensive guide to the most important methods for the introduction of new functionalities is an authoritative resource for everyone working in the field. This book explores many applications, including the plasma polymerization technique, organic surface functionalization by initiated chemical vapor deposition, photoinduced functionalization on polymer surfaces, functionalization of polymers by hydrolysis, aminolysis, reduction, oxidation, surface modification of nanoparticles, and many more. Inside, readers will find information on various applications in the biomedical field, food science, and membrane science. This important book: -Offers a range of polymer functionalization methods for biomedical applications, water filtration membranes, and food science -Contains discussions of the key surface modification methods, including plasma and chemical techniques, as well as applications for nanotechnology, environmental filtration, food science, and biomedicine -Includes contributions from a team of international renowned experts Written for polymer chemists, materials scientists, plasma physicists, analytical chemists, surface physicists, and surface chemists, Surface Modification of Polymers offers a comprehensive and application-oriented review of the important functionalization methods with a special focus on biomedical applications, membrane science, and food science.
Download or read book Molecular Dynamics Method Development and Simulations of Molecule polymer Interactions written by Travis W. Kemper and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: While the second generation REBO potential reproduced reaction enthalpies within reasonable limits, the main deficiency is found to be the short range nature of the potential and the lack of different charge states. However, the computational efficiency allows for a greater sampling of possible reactions, and there for is a good initial evaluation tool to allow for further analysis with more accurate quantum based methods. Next the surface polymerization by ion assisted deposition (SPIAD) process is investigated. The SPIAD process involves the deposition of thermal neutrals and hyperthermal ions to produce oligomer films for use in organic molecule based electronics. In order to study this process thiophene molecules are deposited on thin films of terthiophene. During these simulations the differences in argon and thiophene depositions are examined. In order to investigate the effects of reactivity of the deposited species, argon and atomic oxygen are deposited a set of prototypical polymers. These prototypical polymers, polyethylene, polypropylene and polystyrene, are generated using an amorphous polymer model. Statistical data on probable changes in substrate bonding is presented. Thus, atomic-scale simulations are conducted to advance the plasma and ionbeam treatments of polymer surfaces. Probable modifications are identified using the second generation REBO potential. Sulfur and improved oxygen parameters are developed under the second generation REBO potential formalism. Probable modifications are further analyzed using quantum chemical analysis. To identify the mechanism in which ions modify polymer surfaces.
Download or read book Molecular Dynamics Simulations of Controlled Crystallization written by Reiko Tamaki and published by . This book was released on 2001 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Modeling of Polymer Crystallization and the Effect of Nucleating Agents written by Alexander Jules Bourque and published by . This book was released on 2017 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructure in a semicrystalline polymer material ultimately determines its material properties. Despite the abundance of research into the semicrystalline microstructure and its evolution during crystallization, a clear description of its development remains elusive. The advent of advanced computing and algorithms, however, have promoted molecular modeling of polymer crystallization, providing a new perspective on the development of the microstructure. This thesis revisits and challenges many aspects of microstructural development in macromolecular materials by applying new modeling techniques and recent technologies. Through atomistic simulations of n-alkane crystallization, this thesis presents new molecular evidence of surface nucleation processes that contribute to the propagation of the crystal growth front in a macromolecular system. Crystallization in polymeric systems has long been theorized to proceed by "secondary nucleation." In this work, molecular dynamics (MD) simulations were engineered to probe this surface nucleation process by systematically inducing crystal growth for a system of macromolecules. In a novel application of mean first passage time analysis, the critical surface nucleus sizes, waiting times, and surface nucleation rates were extracted from atomically-detailed molecular trajectories using a layer-by-layer approach. Insight from MD simulations was used to build a new kinetic model to describe the structure and rate of advancement of the growth front during crystallization. In the model, solidification occurs through the mechanisms of surface nucleation and lateral spreading of the solid phase within layers in the vicinity of the growth front. Transformation within each layer is described by an equation similar to the two-dimensional variant of the Johnson-Mehl-Avrami equation. The kinetic model is computationally efficient and predictive of important macroscopic observables. Finally, this thesis presents the first computational screening of nucleating agents for macromolecular crystallization. Screens were conducted for two families of crystal materials: tetrahedrally coordinated materials isomorphic to diamond and silicon, and 2D, hexagonally coordinated materials isomorphic to graphene. The induction time for heterogeneous nucleation was shown to depend strongly on crystallographic registry between the nucleating agent and the critical nucleus, but the severity of this registry requirement weakened with increasing strength of attraction to the surface of the nucleating agent. In an unprecedented find, the substrate rigidity significantly influenced heterogeneous nucleation. The molecular organization of nalkane chains at the nucleating surface was also investigated to build a fundamental understanding of the mechanisms for heterogeneous nucleation and spreading.
Download or read book Conjugated Polymers written by John R. Reynolds and published by CRC Press. This book was released on 2019-03-25 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers properties, processing, and applications of conducting polymers. It discusses properties and characterization, including photophysics and transport. It then moves to processing and morphology of conducting polymers, covering such topics as printing, thermal processing, morphology evolution, conducting polymer composites, thin films
