Download or read book Molecular Dynamics Simulations of Polyhedral Oligomeric Silsesquioxanes written by Tudor Constantin Ionescu and published by . This book was released on 2004 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Dynamics Simulations of Polymer Nanocomposites Containing Polyhedral Oligomeric Silsesquioxanes written by Reena R. Patel and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular dynamics simulations were carried out on traditional polymers copolymerized with POSS (Polyhedral Oligomeric Silsesquioxanes) derivatives to identify the reason behind improved properties imparted to the conventional polymers with the chemical incorporation of POSS. Two classes of systems are used in the present study, namely the polystyrene and polymethyl methacrylate systems. Seven systems are studied in the polystyrene class. The effect of corner substituent groups of the POSS cage on the properties of the polymer nanocomposites was studied using the polystyrene. In addition, the effect of the type of cage structure on the properties was studied using T8, T10 and T12 POSS cage structures containing phenyl substituents on each POSS cage. Systems with polymethyl methacrylate were studied to analyze the effect of mole percent of POSS on the polymer properties, holding the corner substituents on the POSS unit constant. The corner function used was the isobutyl group. The properties analyzed using simulations include glass transition temperature, volumetric thermal expansion coefficient, X-ray scattering data, solubility parameter and mechanical properties. In both polystyrene and polymethyl methacrylate systems, simulations were also carried out on the pure parent polymers for the sake of comparison. The effect of forcefield on the predicted properties was studied using both COMPASS and PCFF forcefields. Performance analysis of the code used in the present simulation was done by analyzing the parallel run time of simulations involving pure atactic polystyrene.

Download or read book Molecular Dynamics Simulations of Polymer Nanocomposites Containing Polyhedral Oligomeric Silsesquioxanes written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular dynamics simulations were carried out on traditional polymers copolymerized with POSS (Polyhedral Oligomeric Silsesquioxanes) derivatives to identify the reason behind improved properties imparted to the conventional polymers with the chemical incorporation of POSS. Two classes of systems are used in the present study, namely the polystyrene and polymethyl methacrylate systems. Seven systems are studied in the polystyrene class. The effect of corner substituent groups of the POSS cage on the properties of the polymer nanocomposites was studied using the polystyrene. In addition, the effect of the type of cage structure on the properties was studied using T8, T10 and T12 POSS cage structures containing phenyl substituents on each POSS cage. Systems with polymethyl methacrylate were studied to analyze the effect of mole percent of POSS on the polymer properties, holding the corner substituents on the POSS unit constant. The corner function used was the isobutyl group. The properties analyzed using simulations include glass transition temperature, volumetric thermal expansion coefficient, X-ray scattering data, solubility parameter and mechanical properties. In both polystyrene and polymethyl methacrylate systems, simulations were also carried out on the pure parent polymers for the sake of comparison. The effect of forcefield on the predicted properties was studied using both COMPASS and PCFF forcefields. Performance analysis of the code used in the present simulation was done by analyzing the parallel run time of simulations involving pure atactic polystyrene.

Download or read book Molecular Dynamics Simulation of Polyhedral Oligomeric Silsesquioxanes POSS and Their Polymeric Nanocomposites written by Jacob Kristian Earnshaw and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This note is part of Quality testing.

Download or read book Multiscale Modeling and Computer Simulation of Polyhedral Oligomeric Silsesquioxane Assemblies written by Elaine R. Chan and published by . This book was released on 2006 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Polyhedral Oligomeric Silsesquioxanes written by Claire Hartmann-Thompson and published by Springer Science & Business Media. This book was released on 2011-01-03 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: The commercial availability and decreasing cost of polyhedral oligomeric silsesquioxanes in recent years has opened up the field to everybody who wishes to apply these unique properties in their own technologies. This is the first book to provide a comprehensive overview of these applications, and covers the synthesis, characterization and history of polyhedral oligomeric silsesquioxanes, their use as metallasilsesquioxane catalysts, their effect upon polymer properties and plastics performance, and their use in superhydrophobic nanocomposites, and electronics, energy, space and biomedical applications. "Applications of Polyhedral Oligomeric Silsesquioxanes" is a valuable reference for those working across a range of disciplines, including chemists, materials scientists, polymer physicists, plastics engineers, surface scientists, and anybody with a commercial or academic interest in plastics, composite materials, space materials, dental materials, tissue engineering, drug delivery, lithography, fuel cells, batteries, lubricants, or liquid crystal, LED, sensor, photovoltaic or biomedical devices.

Download or read book Polyhedral Oligomeric Silsesquioxanes Surfactants written by and published by . This book was released on 2001 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been recent interest in using polyhedral oligomeric silsesquioxanes (POSS) as the smallest particles of silica for reinforcement of polymers. These materials are monodisperse, have tailored functionality (including a hydrophobic coating) and should thus act as model nanoparticulate filler. Feher et al have shown that sol-gel condensation into cage compounds can yield two thermodynamically stable main isolates: a fully condensed R8T8 cube and an incompletely condensed R7T4D3(OH)3 trisilanol. (T refers to a SiO3/2 and D is a SiO2/2 moiety in a silicate framework) There are large differences in the solubility of POSS in common organic solvents based on the substitution of the cages. For example, a fully condensed iBu8T8 cube is more soluble than a similar cyclohexyl Cy8T8 cube which in turn is more soluble than a cyclopentyl Cp8T8 substituted cube. Furthermore the breaking of symmetry in the incompletely condensed cubes could also be expected to enhance solubility/compatibility. The dispersion of POSS will likely determine how well the material can act as a "nanofiller." Farmer et. al. have recently performed molecular dynamics simulations which suggest that POSS molecules have no tendency for aggregation in a polymeric matrix if they are originally well dispersed.

Download or read book Polyhedral Oligomeric Silsesquioxane POSS Polymer Nanocomposites written by Sabu Thomas and published by Elsevier. This book was released on 2021-03-25 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyhedral Oligomeric Silsesquioxane (POSS) Polymer Nanocomposites: From Synthesis to Applications offers extensive coverage of polyhedral oligomeric silsesquioxanes and their nanocomposites, including their synthesis, characterization, interfacial interactions and advanced applications. Sections introduce essentials, information on their preparation and discussions on polymeric materials, including elastomers, thermoplastics, thermosetting polymers, polymer blends and IPNs. Further sections cover the latest analysis techniques, examine the properties of POSS-polymer nanocomposites, and discuss key application areas, such as biological, energy, defense, and space. Finally, issues surrounding industry implementation and lifecycle are explored. This is a valuable reference for researchers, scientists and advanced students in the areas of polymer composites and nanocomposites, polymer chemistry, polymer physics, polymer science, and materials science and engineering. In an industrial setting, this book will be of great interest to scientists, R&D professionals, and engineers across industries and disciplines. Covers all aspects of polyhedral oligomeric silsesquioxanes (POSS) and their nanocomposites, including synthesis and characterization techniques, properties, analysis, applications and trends Targets POSS nanocomposites, describing synthesis, characterization and the selection of POSS filler types according to polymeric material Explains the preparation and utilization of POSS polymer nanocomposites for cutting-edge applications, including biological, energy, and defense field applications

Download or read book Coarse Graining of Condensed Phase and Biomolecular Systems written by Gregory A. Voth and published by CRC Press. This book was released on 2008-09-22 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring recent developments in the field, Coarse-Graining of Condensed Phase and Biomolecular Systems examines systematic ways of constructing coarse-grained representations for complex systems. It explains how this approach can be used in the simulation and modeling of condensed phase and biomolecular systems. Assembling some of the most influential, world-renowned researchers in the field, this book covers the latest developments in the coarse-grained molecular dynamics simulation and modeling of condensed phase and biomolecular systems. Each chapter focuses on specific examples of evolving coarse-graining methodologies and presents results for a variety of complex systems. The contributors discuss the minimalist, inversion, and multiscale approaches to coarse-graining, along with the emerging challenges of coarse-graining. They also connect atomic-level information with new coarse-grained representations of complex systems, such as lipid bilayers, proteins, peptides, and DNA.

Download or read book Simulation of Reaction Dynamics for Synthesis of Energetic Materials and Resistant Coatings written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was the development of theoretical and computational methods to guide the efficient synthesis of HEDM (High Energy Density Matter) for use in advanced propellants and POSS (polyhedral oligomeric silsesquioxanes) for use in coatings resistant to extreme conditions such as heat and abrasion. The research centered on the design of new methodology for the simulation of hydrogen transfer reactions. The projects included the development of the following three types of approaches: grid methods for the calculation of hydrogen vibrational wave functions, nonadiabatic molecular dynamics methods for the simulation of proton transfer in liquids, and the nuclear-electronic orbital method for the incorporation of nuclear quantum effects in electronic molecular orbital calculations. The application of these approaches to hydrogen transfer reactions required for the synthesis of HEDM and POSS will provide insight into the detailed mechanisms, as well as the influence of solvent and substituents on the rates and yields. Such mechanistic information will aid in the efficient synthesis of HEDM and POSS and the design of new materials.

Download or read book Siloxane Based Polymers written by Ignazio Blanco and published by MDPI. This book was released on 2019-07-11 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, a collection of 12 original contributions and 4 reviews, provides a selection of the most recent advances in the preparation, characterization, and applications of polymeric nanocomposites comprising nanoparticles. The concept of nanoparticle-reinforced polymers came about three decades ago, following the outstanding discovery of fullerenes and carbon nanotubes. One of the main ideas behind this approach is to improve the matrix mechanical performance. The nanoparticles exhibit higher specific surface area, surface energy, and density compared to microparticles and, hence, lower nanofiller concentrations are needed to attain properties comparable to, or even better than, those obtained by conventional microfiller loadings, which facilitates processing and minimizes the increase in composite weight. The addition of nanoparticles into different polymer matrices opens up an important research area in the field of composite materials. Moreover, many different types of inorganic nanoparticles, such as quantum dots, metal oxides, and ceramic and metallic nanoparticles, have been incorporated into polymers for their application in a wide range of fields, ranging from medicine to photovoltaics, packaging, and structural applications.

Download or read book Dynamic Mechanical and Creep Recovery Behavior of Polymer Based Composites written by Akarsh Verma and published by Elsevier. This book was released on 2024-01-19 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic Mechanical and Creep-Recovery Behaviour of Polymer-Based Composites: Mechanical and Mathematical Modeling covers mathematical modelling, dynamic mechanical analysis, and the ways in which various factors impact the creep-recovery behaviour of polymer composites. The effects of polymer molecular weight, plasticizers, cross-linking agents, and chemical treatment of filler material are addressed and information on thermoplastic and thermosetting polymer-based composites is also covered, including their various applications and the advantages and disadvantages of their use in different settings. The final 2 chapters of the book cover mathematical modeling of creep-recovery behavior for polymer composites and software-based simulation of creep-recovery in polymer composites, respectively. Dynamic Mechanical and Creep-Recovery Behaviour of Polymer-Based Composites: Mechanical and Mathematical Modeling covers mathematical modelling, dynamic mechanical analysis, and the ways in which various factors impact the creep-recovery behaviour of polymer composites. The effects of polymer molecular weight, plasticizers, cross-linking agents, and chemical treatment of filler material are addressed and information on thermoplastic and thermosetting polymer-based composites is also covered, including their various applications and the advantages and disadvantages of their use in different settings. The final 2 chapters of the book cover mathematical modeling of creep-recovery behavior for polymer composites and software-based simulation of creep-recovery in polymer composites, respectively. Analyzes the dynamic mechanical and creep-recovery behaviors of thermoplastic and thermosetting polymer composites in a variety of applications Features diverse mechanical/mathematical models utilized to fit data collected from creep-recovery studies Covers various factors that influence dynamic mechanical properties Discusses the advantages and disadvantages of using these materials in different settings

Download or read book Issues in Computation 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-05-01 with total page 1160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Computation / 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Computing. The editors have built Issues in Computation: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Computing in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Computation / 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Functional Molecular Silicon Compounds I written by David Scheschkewitz and published by Springer. This book was released on 2014-07-08 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Structure and Bonding publishes critical reviews on topics of research concerned with chemical structure and bonding. The scope of the series spans the entire Periodic Table and addresses structure and bonding issues associated with all of the elements. It also focuses attention on new and developing areas of modern structural and theoretical chemistry such as nanostructures, molecular electronics, designed molecular solids, surfaces, metal clusters and supramolecular structures. Physical and spectroscopic techniques used to determine, examine and model structures fall within the purview of Structure and Bonding to the extent that the focus is on the scientific results obtained and not on specialist information concerning the techniques themselves. Issues associated with the development of bonding models and generalizations that illuminate the reactivity pathways and rates of chemical processes are also relevant. The individual volumes in the series are thematic. The goal of each volume is to give the reader, whether at a university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to a larger scientific audience. Thus each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years should be presented using selected examples to illustrate the principles discussed. A description of the physical basis of the experimental techniques that have been used to provide the primary data may also be appropriate, if it has not been covered in detail elsewhere. The coverage need not be exhaustive in data, but should rather be conceptual, concentrating on the new principles being developed that will allow the reader, who is not a specialist in the area covered, to understand the data presented. Discussion of possible future research directions in the area is welcomed. Review articles for the individual volumes are invited by the volume editors. Readership: research scientists at universities or in industry, graduate students Special offer For all customers who have a standing order to the print version of Structure and Bonding, we offer free access to the electronic volumes of the Series published in the current year via SpringerLink.

Download or read book Polymer POSS Nanocomposites and Hybrid Materials written by Susheel Kalia and published by Springer. This book was released on 2018-11-27 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of polymer nanocomposites and hybrid materials with polyhedral oligomeric silsesquioxanes (POSS). Among inorganic nanoparticles, functionalized POSS are unique nano-building blocks that can be used to create a wide variety of hybrid and composite materials, where precise control of nanostructures and properties is required. This book describes the influence of incorporation of POSS moieties into (organic) polymer matrices on the mechanical, thermal and flammability behavior of composites and hybrid organic-inorganic materials. Importantly, POSS-containing materials can be bio-functionalized by linking e.g. peptides and growth factors through appropriate surface modification in order to enhance the haemo-compatibility of cardiovascular devices made of these materials. This volume includes descriptions of synthesis routes of POSS and POSS-containing polymeric materials (e.g. based on polyolefines, epoxy resins and polyurethanes), presentation of POSS’ role as flame retardants and as biocompatible linker, as well as the depiction of decomposition and ageing processes.

Download or read book Thermal Degradation of Polymeric Materials written by Krzysztof Pielichowski and published by Elsevier. This book was released on 2022-11-05 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal Degradation of Polymeric Materials, Second Edition offers a wealth of information for polymer researchers and processors who require a thorough understanding of the implications of thermal degradation on materials and product performance. Sections cover thermal degradation mechanisms and kinetics, as well as various techniques, such as thermogravimetry in combination with mass spectroscopy and infrared spectrometry to investigate thermal decomposition routes. Other chapters focus on polymers and copolymers, including polyolefins, styrene polymers, polyvinyl chloride, polyamides, polyurethanes, polyesters, polyacrylates, natural polymers, inorganic polymers, high temperature-resistant and conducting polymers, blends, organic-inorganic hybrid materials, nanocomposites, and biocomposites. Finally, other key considerations such as recycling of polymers by thermal degradation, thermal degradation during processing, and modelling, are discussed in detail. Explains mechanisms of polymer degradation, making it possible to understand and predict material behavior at elevated temperatures Offers systematic coverage of each polymer group that is supported by data detailed explanations and critical analysis Investigates thermal decomposition routes in new materials, such as organic-inorganic hybrid materials and polymer nanocomposites

Download or read book Simulation of Reaction Dynamics Nonadiabatic and Solvation Effects written by and published by . This book was released on 2001 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research involved four projects centered on the design of theoretical and computational approaches to predict promising energetic materials and to guide the efficient synthesis of these materials. First, mixed quantum/classical methodology was developed for the simulation of photochemical reactions, which could play an important role in the design and synthesis of energetic materials. Second, the time-dependent self-consistent-field reaction path Hamiltonian method was developed for the calculation of the real-time quantum dynamics of polyatomic reactions. Third, a new approach for investigating the solvent effects of fundamental organic reactions was developed in order to aid in the efficient synthesis of energetic materials. This approach combined electronic structure calculations with reactive flux molecular dynamics calculations based on a reaction path Hamiltonian. Application of this approach to two fundamental organic reactions provided insight into the dynamical role of solvent and elucidated possible reaction mechanisms. Fourth, the Fourier grid Hamiltonian multi configurational self-consistent-field and partial multidimensional grid generation methods were developed for the efficient calculation of multidimensional hydrogen vibrational wavefunctions. These two methods enable the simulation of hydrogen transfer reactions required for the synthesis of polyhedral oligomeric silsesquioxanes, which are used in coatings that are resistant to extreme conditions such as heat and abrasion.