Structure and Morphology of Sulfonated Polysulfone and Perfluorosulfonic Acid Ionomers PDF Download
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Author: Chen Wang (Chemical engineer)
Publisher:
ISBN:
Category : Ionomers
Languages : en
Pages : 191
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Book Description
The limitations of conventional perfluorosulfonic acid (PFSA) based membrane materials have provoked the search for alternative materials which can function as the electrolyte in PEM fuel cells operated at higher temperatures (> 100 °C) and without humidification. A novel class of sulfonated poly(phenylene) sulfone (sPSO2) ionomers have shown much higher proton conductivity than typical PFSA membranes at elevated temperatures. In this dissertation, both computational and experimental methods were used to investigate proton transfer, morphological and structural properties of sPSO2 and PFSA ionomers. We have undertaken ab initio electronic structure calculations to understand the primary hydration and the transfer of protons in oligomeric fragments of sPSO2 ionomers. The effects of equivalent weight, molecular weight and water content on swelling properties of hydrated sPSO2 ionomers were investigated by dissipative particle dynamics (DPD) simulations. The micro-phase separation in hydrated PFSA ionomers was studied by using BF and HAADF imaging in a TEM/STEM. The microstructural evolution as a function of water content is observed and in a good agreement with the results from previous DPD simulations. To understand local chemistry and molecular structures of ionomers, quantitative analyses were conducted based on the results from EELS in the low loss and core loss regions. Finally, the influence of phase transitions and polarization in PTFE chains was determined by comparing experimental and simulated EELS.
Author: Chen Wang (Chemical engineer)
Publisher:
ISBN:
Category : Ionomers
Languages : en
Pages : 191
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Book Description
The limitations of conventional perfluorosulfonic acid (PFSA) based membrane materials have provoked the search for alternative materials which can function as the electrolyte in PEM fuel cells operated at higher temperatures (> 100 °C) and without humidification. A novel class of sulfonated poly(phenylene) sulfone (sPSO2) ionomers have shown much higher proton conductivity than typical PFSA membranes at elevated temperatures. In this dissertation, both computational and experimental methods were used to investigate proton transfer, morphological and structural properties of sPSO2 and PFSA ionomers. We have undertaken ab initio electronic structure calculations to understand the primary hydration and the transfer of protons in oligomeric fragments of sPSO2 ionomers. The effects of equivalent weight, molecular weight and water content on swelling properties of hydrated sPSO2 ionomers were investigated by dissipative particle dynamics (DPD) simulations. The micro-phase separation in hydrated PFSA ionomers was studied by using BF and HAADF imaging in a TEM/STEM. The microstructural evolution as a function of water content is observed and in a good agreement with the results from previous DPD simulations. To understand local chemistry and molecular structures of ionomers, quantitative analyses were conducted based on the results from EELS in the low loss and core loss regions. Finally, the influence of phase transitions and polarization in PTFE chains was determined by comparing experimental and simulated EELS.
Author: Michel Pineri
Publisher: Springer Science & Business Media
ISBN: 9400938292
Category : Science
Languages : en
Pages : 579
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Book Description
Ionomers, that is polymers containing a low concentration of charged units along the chain, have been the subject of increasing interest during the past twenty years. The presence of ionic groups in the poly mer changes some of its properties dramatically. Increases in the modu lus and the viscosity of several orders of magnitude have been observed, and changes in the glass transition of hundreds of degrees are possible. In addition, diffusion coefficients can be modified drastically. These changes are due primarily to the presence of reversible ionic cross links in these materials. Because of the low dielectric constant of most organic polymers, the ions or ionic dipoles tend to aggregate ; this aggregation process, however, is limited, because the ionic groups are covalently bonded to the organic chain. Host of the fundamental research done on these materials has been devoted to a determination of the extent of association, the structure of the aggregates, the limi ting factors, and the correlations between molecular and supermolecular structure and the resul ting properties.
Author: M.R. Tant
Publisher: Springer Science & Business Media
ISBN: 940091461X
Category : Technology & Engineering
Languages : en
Pages : 524
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Book Description
Polymers have achieved an enviable position as the class of materials having the highest volume of production, exceeding that of both metals and ceramics. The meteoric rise in the production and utilization of polymers has been due to advances in polymer synthesis which allow the creation of specific and well-defined molecular structures, to new knowledge concerning the relationships between polymer structure and properties, and to an improved understanding of how processing can be used as a tool to develop morphological features which result in desired properties. Polymers have truly become 'engineered materials' in every sense of the term. Polymer scientists and engineers are forever seeking to modify and improve the properties of synthetic polymeric systems for use in specific applications. Towards this end they have often looked to nature for advice on how to design molecules for specific needs. An excellent illustration of this is the use of noncovalent bonding (ionic, hydrogen, and van der Waals) in lipids, proteins, and nucleic acids, where these noncovalent bonds, acting both intra and intermolecularly, precisely control the structure and thus the function of the entire system. The utilization of ionic bonding, in particular in man-made polymers has attracted widespread interest in recent years, since ionic interactions exert a similar strong influence on the structure and properties of these synthetic systems.
Author: Michael A. Drzewinski
Publisher:
ISBN:
Category : Ionomers
Languages : en
Pages : 252
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Book Description
Author: Toshikatsu Sata
Publisher: Royal Society of Chemistry
ISBN: 1847551173
Category : Science
Languages : en
Pages : 325
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Book Description
Various separation membranes have been developed since their discovery over half a century ago, providing numerous benefits and fulfilling many applications in our everyday lives. They lend themselves to techniques ranging from microfiltration and gas separation, to what can be considered as the most advanced technique - ion exchange. This book, aimed at academic researchers, engineers and industrialists, contains a brief history of ion exchange and goes on to explain the preparation, characterization, modification and applications of these important membranes. Discussions include the use of ion exchange in analytical and medical techniques, as well as the development of future applications.
Author: Ram K. Gupta
Publisher: Springer Nature
ISBN: 3030980219
Category : Technology & Engineering
Languages : en
Pages : 432
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Book Description
This book covers synthesis, properties, and applications of organic electrodes for advanced electrochemical applications. The future applications and challenges in using organic electrodes are also explored. The chapters describe their unique electrochemical properties, surface area, nano-device integration, multifunctionality, printability, and mechanical flexibility. In this book, basic concepts and emerging electrochemical applications such as batteries, supercapacitors, solar cells, fuel cells, and sensors of organic materials are covered. Apart from conventional techniques, this book explores new aspects of synthesizing organic electrodes for novel organic materials with advanced applications.
Author: Dmitri Bessarabov
Publisher: Academic Press
ISBN: 0081028318
Category : Science
Languages : en
Pages : 140
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Book Description
PEM Water Electrolysis, a volume in the Hydrogen Energy and Fuel Cell Primers series presents the most recent advances in the field. It brings together information that has thus far been scattered in many different sources under one single title, making it a useful reference for industry professionals, researchers and graduate students. Volumes One and Two allow readers to identify technology gaps for commercially viable PEM electrolysis systems for energy applications and examine the fundamentals of PEM electrolysis and selected research topics that are top of mind for the academic and industry community, such as gas cross-over and AST protocols. The book lays the foundation for the exploration of the current industrial trends for PEM electrolysis, such as power to gas application and a strong focus on the current trends in the application of PEM electrolysis associated with energy storage. - Presents the fundamentals and most current knowledge in proton exchange membrane water electrolyzers - Explores the technology gaps and challenges for commercial deployment of PEM water electrolysis technologies - Includes unconventional systems, such as ozone generators - Brings together information from many different sources under one single title, making it a useful reference for industry professionals, researchers and graduate students alike
Author: Antonio Salvatore Aricò
Publisher:
ISBN: 9781608768653
Category : Direct energy conversion
Languages : en
Pages : 0
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Book Description
This book deals with an analysis of materials issues, status of technologies and potential applications of direct methanol fuel cells. The principle of operation of direct methanol fuel cells and the status of knowledge in the basic research areas are presented. The technology of direct methanol fuel cells is discussed in this book with particular regard to fabrication methodologies for the manufacturing of catalysts, electrolytes membrane-electrode assemblies, stack hardware and system design.
Author: Dmitri Bessarabov
Publisher: CRC Press
ISBN: 1482252325
Category : Science
Languages : en
Pages : 401
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Book Description
An ever-increasing dependence on green energy has brought on a renewed interest in polymer electrolyte membrane (PEM) electrolysis as a viable solution for hydrogen production. While alkaline water electrolyzers have been used in the production of hydrogen for many years, there are certain advantages associated with PEM electrolysis and its relevan
Author: Alfred Rudin
Publisher: Elsevier
ISBN: 0080505473
Category : Technology & Engineering
Languages : en
Pages : 529
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Book Description
Tremendous developments in the field of polymer science, its growing importance, and an increase in the number of polymer science courses in both physics and chemistry departments have led to the revision of the First Edition. This new edition addresses subjects as spectroscopy (NMR), dynamic light scattering, and other modern techniques unknown before the publication of the First Edition. The Second Edition focuses on both theory (physics and chemistry) and engineering applications which make it useful for chemistry, physics, and chemical engineering departments.
