Download or read book Synthesis And Characterization Of Polymeric Anion Exchange Membranes written by Wenxu Zhang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As alkaline anion exchange membrane fuel cells (AAEMFC) are regarded as promising and important energy devices, the development of high performance anion exchange membranes are in urgent need, as well as fundamental investigation on the structure-property relationship, which are the motivation of this dissertation. Three different polymer systems are presented and focused on polymer synthesis, material morphology, and ion transport phenomena. Crosslinked membranes are promising as practical materials, however, the understanding and further improvement of its performance is hindered by the lack of an ordered morphology or well-defined chemical structure. In Chapter 2, a series of crosslinked membranes were design to bear cationic groups organized via covalent linkages, which were synthesized by sequential reversible addition-fragmentation chain transfer radical polymerization (RAFT), "click" chemistry, cast/crosslinking process, and solid state quaternization. Significant enhancement in conductivities was observed and presumably attributed to the formation of ion transport channels directed by polycation chains. Excellent membrane performance were observed, including conductivities, water diffusivities, and fuel cell power densities. In Chapter 3, phosphonium containing block copolymers were synthesized and subjected to morphology characterization. Using Small Angle X-ray Scattering (SAXS) and Transmission Electron Microscopy (TEM), it was observed that these materials form well-ordered morphologies upon solvent casting, and the ionic block preferred to form a continuous phase. By comparing the anion conductivities, the matrix in a hexagonal phase was proved to be more efficient in ion transport than lamellae. Polycyclooctene (PCOE) based triblock copolymers were synthesized in Chapter 4, by using a special chain transfer agent (CTA) to mediate Ring-Opening Metathesis Polymerization (ROMP) and reversible addition-fragmentation chain transfer radical polymerization (RAFT). The well-defined melting transition (~50 oC) of PCOE enabled the investigation of the thermal transition in hydrophobic block affecting ionic domain behavior. Then metal ion doped star block copolymers were investigated in bulk and thin film forms to demonstrate that the star block copolymer architecture can facilitate microphase separation and thus the preparation of smaller features. Using an ortho-nitrobenzyl ester junction, triblock copolymers based on PEO and PSt were synthesized and applied to hierarchical pattern fabrication in self-assembled thin films. During these studies, the single monomer insertion methodology was developed for high efficiency synthesis of (multi)functional RAFT CTAs. The molecular characterization and controlled polymerization results were documented in Chapter 7. The last chapter contains outlooks based on the research in this dissertation. Methods to improve the previously presented materials were listed. Also, fundamental questions were raised on ion transport membranes, and possible ways to answer them were provided. In addition, potential research directions are proposed.

Download or read book Ion Exchange Membranes written by Toshikatsu Sata and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Synthesis and Characterization of Block Copolymer Anion Exchange Membranes and Superimide Proton Exchange Membranes written by Lizhu Wang and published by . This book was released on 2014 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Physico chemical Characterization of Anion exchange Polymeric Materials for Electrochemical Applications written by Antonio Filpi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Phosphonium Containing Cationic Poly styrene Polymers written by and published by . This book was released on 2009 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alkaline fuel cells have been proposed as a cost effective alternative energy solution due to their cheap manufacture and low operating temperatures. Their mass utilization, however, is hindered by their electrolyte material. While relatively inexpensive solid proton exchange membranes have been available for some time now, alkaline fuel cells still rely on liquid electrolyte to provide mobility to the anionic species. In this technical note, we describe an ionomeric system designed as an anion exchange membrane for these types of applications. Styrene monomer has been copolymerized with 4-vinylbenzyltrimethylphosphonium chloride to produce several statistical copolymers via reversible addition-fragmentation chain transfer (RAFT) polymerization, a controlled radical polymerization method. The synthetic approach and preliminary results are discussed, as well as future plans.

Download or read book Synthesis and Characterization of Polymer Electrolyte Membranes with Controlled Ion Transport Properties written by Kui Xu and published by . This book was released on 2011 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymeric Membrane Synthesis Modification and Applications written by Chandan Das and published by CRC Press. This book was released on 2018-10-12 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Membranes and membrane separation techniques have grown from a simple laboratory tool to an industrial process with considerable technical and commercial impact. The book deals with both the fundamental concepts of preparation, characterization and modification, practical applications along with recent advancements of electro-spun and phase inverted polymeric membranes. Divided into two parts, part one of this book covers the fundamental concepts and practical applications of novel electro-spun membranes while the latter covers basic concepts and further advancements of the conventional phase inverted membranes extensively. Key Features Covers fundamental concepts and practical applications of electro-spun and phase inverted polymeric membranes Includes general properties, characterization, preparation and modification of polymeric membranes Discusses advanced modification of polymeric membranes (functionalization, grafting) using phase inversion process, and effects of solubility parameter and additives on the phase inversion process Reviews electro-spun membranes for biomedical applications, industrial effluents treatment and removal of water contaminants Explores a separate economic analysis section for the discussed membranes

Download or read book Synthesis and Characterization of Anion Exchange Blend Membranes for Vanadium Redox Flow Battery Applications written by Hyeongrae Cho and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhancements of the Synthesis and Fabrication of Anion Exchange Membranes written by Megan Matta and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion exchange membranes (IEMs) have emerged as important components in a wide variety of electrochemical processes and applications, playing a vital role in facilitating the selective transport of ions while preventing species crossover between the anolyte and catholyte. These versatile polymer or polymer composite membranes find uses in diverse fields such as energy conversion and storage, water treatment, chemical synthesis, and biotechnology. At the core of their functionality, ion exchange membranes exhibit a unique property known as "selective permeability." This property allows them to permit the controlled movement of specific ions across their structure based on differences in charge and size, while restricting the transport of other species. Diffusion of other molecules, such as water, can also be controlled simultaneously by optimizing the ion content, water uptake, and polymer structure of these materials. The design and synthesis of ion exchange membranes involve the incorporation of charged functional groups capable of exchanging ions with the surrounding solution. This functional group can be embedded in the backbone of the polymer, in an ionene-type structure, or attached to the backbone by tethered side chains. IEMs are broadly classified by the charge of the functional group into cation exchange membranes (CEMs) and anion exchange membranes (AEMs). CEMs have anionic functional groups and permit the transport of cations, whereas AEMs have cationic functional groups and permit the transport of anions. Bipolar membranes (BPM) are a type of composite IEM consisting of an AEM and CEM laminated together and an interesting topic of future research. Most AEMs produced today contain chemically unstable arylene ether backbones, have poor mechanical properties, and require toxic reagents for functionalization. This dissertation seeks to synthesize new anion exchange membranes that are stable in alkaline conditions while maintaining the high conductivities required for the operation of electrochemical devices. To develop a chemically stable aliphatic polyolefin AEM, a library of polymers synthesized via Ziegler-Natta polymerization was examined. This library consisted of quaternized poly(11-bromo-1-undecene-co-4-phenyl-2-butene) with degrees of functionalization of 20 mol% to 50 mol% -- and was made utilizing a different catalyst system than previously explored. A TiCl3ˑAA catalyst was reacted with triisobutylaluminum (TiBA) co-catalyst to synthesize a more robust catalyst complex than the traditional AlEt2Cl catalyst. It was found that this new system could incorporate a higher amount of halogenated monomer (up to 50 mol %) on a multi-gram scale (50 g) at high yield without poisoning and deactivating the catalyst. The monomer incorporation was equal to the monomer feed and allowed for the targeting of specific ion exchange capacities. A large-scale synthesis (100 g) was conducted to assess the feasibility of pilot scale experiments. The dissolved polymers were solvent cast onto an ePTFE support and heterogeneously quaternized by immersing the alkylbromide-functionalized membrane in trimethyl amine solution. This procedure resulted in uneven wrinkled membranes, and a new method of casting supported membranes was subsequently developed, as described below. The hydroxide conductivity of the membranes was measured at room temperature, with conductivities up to 32 mS/cm reported. Given the issues with deformities in the supported membranes, further work focused on developing more efficient and consistent methods of membrane fabrication. It is speculated from initial experiments that high molecular weight polymer was being filtered from the sample during solution processing -- decreasing the mechanical strength of cast membranes. The quaternary ammonium-functionalized polyolefins were cryomilled to retain high molecular weight polymer without aggregation. Casting membranes from the cryomilled powder increased the mechanical properties of the membrane such that the mechanical membrane support was no longer needed. Moreover, cryomilling facilitated bulk heterogenous quaternization of the polymer prior to membrane fabrication, reducing the amount of trimethylamine solution needed. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) measurements confirmed that the Menshutkin reaction went to completion and all bromine moieties were quaternized for all degrees of functionalization. The quaternized polymer resins were cryomilled to yield a free-flowing powder that could be used for AEM fabrication. The polymers were examined with thermogravimetric analysis, and the degradation temperature of the ammonium was found to be 215 °C in the chloride form. Suggesting that thermal processing, such as heat pressing, is a viable option for membrane fabrication. Environmentally benign ethanol as a solvent was utilized to disperse the powder and cast membranes unsupported. The resulting AEMs were smooth, with even appearance across the sample, and thin, with thicknesses ranging between 15 [mu]m and 20 [mu]m. Preliminary synthesis on a monomer for ring opening metathesis polymerization (ROMP) was attempted in an effort to examine the effects of well-defined backbone architecture on conductivity and chemical durability. The monomer, 3-(N,N'-dimethylpropyl-1-amine)-cyclooctene, was synthesized in high purity and characterized by proton NMR. Unfortunately attempts to polymerize the monomer via ROMP were unsuccessful as of the writing of this dissertation.

Download or read book Ion Exchange Membranes written by Tongwen Xu and published by John Wiley & Sons. This book was released on 2024-05-28 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion Exchange Membranes A comprehensive introduction to the electro-membrane technologies of the future An ion exchange membrane is a polymer-based membrane which can be permeable by some ions in a solution while blocking others, making them ideal for processes such as water desalination, salt concentration control, clean production and—given their electrical conductivity—power generation and energy storage etc. Recent advances have given rise to new electro-membrane processes that promise drastically to expand the applications of this technology. Scientists in both research and industry will increasingly need to draw on these membranes in vital ways with strongly positive potential environmental impact. Ion Exchange Membranes summarizes recent research into these membranes and electro-membrane processes before moving to an overview of the historical background. It then attends in detail to cutting-edge fabrication technologies and the most recent areas of use. The result is a comprehensive introduction to the design, fabrication, and applications of these increasingly essential membranes. Ion Exchange Membranes readers will also find: In-depth treatment of industrial-scale applications Detailed discussion of topics including side-chain engineering, polyacylation, superacid-catalyst polymerization, and more Analysis of electro-membrane processes such as alkaline membrane water electrolysis, solar-driven water splitting, and many more Ion Exchange Membranes is ideal for membrane scientists, materials scientists, inorganic chemists, polymer chemists, and researchers and engineers in a variety of fields working with ion exchange membranes and electro-membrane processes.

Download or read book Ionomers written by M.R. Tant and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Ion Exchange Membrane Separation Processes written by H Strathmann and published by Elsevier. This book was released on 2004-01-29 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today, membranes and membrane processes are used as efficient tools for the separation of liquid mixtures or gases in the chemical and biomedical industry, in water desalination and wastewater purification. Despite the fact that various membrane processes, like reverse osmosis, are described in great detail in a number of books, processes involving ion-exchange membranes are only described in a fragmented way in scientific journals and patents; even though large industrial applications, like electrodialysis, have been around for over half a century. Therefore, this book is emphasizing on the most relevant aspects of ion-exchange membranes. This book provides a comprehensive overview of ion-exchange membrane separation processes covering the fundamentals as well as recent developments of the different products and processes and their applications. The audience for this book is heterogeneous, as it includes plant managers and process engineers as well as research scientists and graduate students. The separate chapters are based on different topics. The first chapter describes the relevant Electromembrane processes in a general overview. The second chapter explains thermodynamic and physicochemical fundamentals. The third chapter gives information about ion-exchange membrane preparation techniques, while the fourth and fifth chapter discusses the processes as unit operations giving examples for the design of specific plants. First work on the principles and applications of electrodialysis and related separation processes Presently no other comprehensive work that can serve as both reference work and text book is available Book is suited for teaching students and as source for detailed information

Download or read book Superelectrophiles and Their Chemistry written by George A. Olah and published by John Wiley & Sons. This book was released on 2008-01-03 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superelectrophiles and Their Chemistry contains, for the first-time, a discussion of the basics of this emerging field of organic chemistry, alongside tools to help the reader apply the chemistry. Specific tools include an evaluation of the ways to increase the strength of electrophiles, the classification of superelectrophiles, the solvation issues, a review of methods for studying superelectrophilicity, with details of the superelectrophiles that have been identified and studied. Additional information includes substituent effects in activation of superelectrophiles, and solvation in chemical reactions, as well as an insightful look into future applications.

Download or read book Electrochemical Polymer Electrolyte Membranes written by Jianhua Fang and published by CRC Press. This book was released on 2015-04-17 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Disc

Download or read book Quaternized Fluorene based Hydroxide Exchange Membranes and Polymers Design Synthesis and Characterization written by Andrit Allushi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infections by pathogenic microorganisms remain one of the most serious concerns in several areas, particularly in hygienic applications. Antimicrobials have been used to combat these infections. Using small molecular antimicrobials as additives or coatings is an industrially adopted strategy. However, small antimicrobial agents always suffer from many drawbacks, such as leaching potential, toxicity to the environment, antimicrobial resistance. The development of antimicrobial polymers provides a promising strategy to overcome these issues. Compared to small molecular antimicrobials, antimicrobial polymers have advantages like enhanced antimicrobial efficiency, reduced toxicity, longer lifetime and lower risk to develop antimicrobial resistance. Most research has been focused on cationic antimicrobial polymers which can disrupt bacterial membranes by electrostatic interactions. The major issues with cationic antimicrobial polymers are their undesirable high-water solubility, toxicity, fouiling potential and poor miscibility with nonionic polymer matrices. To solve these problems, continued exploration of new nonionic antimicrobial polymers is highly valuable and that is where this thesis has been focusing on. In this work, we have designed and synthesized different nonionic antimicrobial polymers with isatin or indole functionality, including hyperbranched and linear structures. The antimicrobial properties against various bacteria of these polymers were evaluated. In general, these bio-based polymers exhibited significant antimicrobial activity, higher than their corresponding small model compounds. We also found that ether unit may have a synergistic effect to interact with certain bacterial membranes. It was also observed that the N-H moiety of indole in the polymer's structure facilitate the hydrogen bonding with the C=O moiety of polyesters, which improved their miscibility. Finally, we evaluated the hemolytic activity and cytotoxicity of the obtained polymers. As a result, they showed negligible cytotoxic effect to red blood cells and MG-63 osteoblast-like cells, which indicates their potential in biomedical applications.

Download or read book Mechanical Characterization of Anion Exchange Membranes Under Controlled Environmental Conditions written by Benjamin R. Caire and published by . This book was released on 2015 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Polymer Blend Membranes for Direct Methanol Fuel Cell Applications written by Carmen Manea and published by . This book was released on 2001 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: