Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Multi Block Sulfonated Polyphenylene Copolymer Proton Exchange Membranes
Download Multi Block Sulfonated Polyphenylene Copolymer Proton Exchange Membranes full books in PDF, epub, and Kindle. Read online Multi Block Sulfonated Polyphenylene Copolymer Proton Exchange Membranes ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Multi-block Sulfonated Poly(phenylene) Copolymer Proton Exchange Membranes by :
Download or read book Multi-block Sulfonated Poly(phenylene) Copolymer Proton Exchange Membranes written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.
Book Synopsis Polyphenylene Sulfonic Acids as Proton Exchange Membranes for Fuel Cells by : Daxuan Dong
Download or read book Polyphenylene Sulfonic Acids as Proton Exchange Membranes for Fuel Cells written by Daxuan Dong and published by . This book was released on 2012 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: High molecular weight poly(biphenyl-3,3'-disulfonic acid) (PBPDSA) homopolymer was synthesized using the Ullmann coupling reaction. The molecular weight of PBPDSA was improved by changing the solvent, counter ion and drying method. A water insoluble copolymer PBPDSA-g-NPB was obtained by grafting PBPDSA with neopentylbenzene (NPB). The proton conductivity of this film was 0.114 S/cm at 50%RH and 80oC, which is higher than the initial DOE target 0.1 S/cm. In order to further improve the conductivity, a novel copolymer poly(phenylene disulfonic acid_co-fluorene disulfonic acid) (PxF1)was designed and synthesized. PxF1 was synthesized by reacting 1,4-dibromobenzene-2,5-disulfonic acid (DBPDSA) and 2,7-dibromofluorene-3,5-disulfonic acid (DBFDSA) using the Ullmann coupling. This copolymerization was optimized by screening temperature, solvent, coordination reagent and drying method. The best conditions are DBPDSA-Li, DBFDSA-Li and copper dried separately under vacuum and then together under an argon steam at 200oC and copolymerized in NMP at 200oC using 2,2'-bipyridine (BPy) as a coordination reagent. In order to obtain water insoluble membranes, PxF1 was further grafted with benzyl groups and crosslinked. PxF1 and its grafted copolymers exhibited an abnormal increase in reduced viscosity at low concentrations. The Polarizing Optical Microscopy (POM) studies, the film dimensional changes as a function of relative humidities and WAXD measurements are consistent with a nematic liquid crystalline structure. A copolymer hexagonal packing model was proposed and verified by studying the relationship between the calculated molar volume and the measured molar volume using a curve fitting program. The use of WAXD combined with measurements of volume and weight increase for copolymer as a function of relative humidity enabled us to make a direct estimate of frozen-in free volume. The frozen-in free volume from this analysis is 32.0 cc/SO3H (n = 1.8) for P10F1 and 32.1 cc/SO3H (n = 1.8) for P10F1-g-Bn27% (4-46). The in plane proton conductivity of these materials, measured as a function of relative humidity and temperature, was 10 times higher than that of Nafion212 . TGA study indicates that the copolymers are stable up to 304oC. The mechanical properties of those copolymers are affected by the grafting degree and relative humidity. The grafted copolymer has reasonable mechanical properties (breaking stress 13.3 MPa at 6.6% strain) at 23%RH
Book Synopsis Epoxy-crosslinked Sulfonated Poly (phenylene) Copolymer Proton Exchange Membranes by :
Download or read book Epoxy-crosslinked Sulfonated Poly (phenylene) Copolymer Proton Exchange Membranes written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub. 2 crossover rates.
Book Synopsis Handbook of Fluoropolymer Science and Technology by : Dennis W. Smith
Download or read book Handbook of Fluoropolymer Science and Technology written by Dennis W. Smith and published by John Wiley & Sons. This book was released on 2014-05-05 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Fluoropolymer Science and Technology A comprehensive handbook on fluoropolymer synthesis, characterization, and processing Fluoropolymers, one of the more durable classes of polymer materials, are known to enable novel technologies as a result of their remarkable properties. As key components in industry applications, fluoropolymers have established commercial interest and scientists have discovered more efficient approaches of handling them. This book reviews up-to-date fluoropolymer platforms as well as recently discovered methods for the preparation of fluorinated materials. It focuses on synthesis, characterization, and processing aspects, providing guidelines for practicing scientists and engineers. In addition, the book covers: Concepts and studies from leading international laboratories, including academia, government, and industrial institutions Emerging technologies and applications in energy, optics, space exploration, fuel cells, microelectronics, gas separation membranes, biomedical instrumentation, and more Current environmental concerns associated with fluoropolymers, relevant regulations, and growth opportunities Overall, the chapters provide coverage of chemical methods and help the reader further understand how fluoropolymer research provides solutions for material challenges. The concepts in this book also inspire professionals to identify new markets and funding sources for fluoropolymer research and development.
Book Synopsis Synthesis and Characterization of Proton Conducting, Fluorine-containing Block Copolymers by : Zhi Qing Shi
Download or read book Synthesis and Characterization of Proton Conducting, Fluorine-containing Block Copolymers written by Zhi Qing Shi and published by . This book was released on 2004 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis and Characterization of Block Copolymer Anion Exchange Membranes and Superimide Proton Exchange Membranes by : Lizhu Wang
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:
Book Synopsis Random and Block Sulfonated Polyaramides as Advanced Proton Exchange Membranes by :
Download or read book Random and Block Sulfonated Polyaramides as Advanced Proton Exchange Membranes written by and published by . This book was released on 2015 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present here the experimental and computational characterization of two novel copolyaramide proton exchange membranes (PEMs) with higher conductivity than Nafion at relatively high temperatures, good mechanical properties, high thermal stability, and the capability to operate in low humidity conditions. The random and block copolyaramide PEMs are found to possess different ion exchange capacities (IEC) in addition to subtle structural and morphological differences, which impact the stability and conductivity of the membranes. SAXS patterns indicate the ionomer peak for the dry block copolymer resides at q = 0.1 Å-1, which increases in amplitude when initially hydrated to 25% relative humidity, but then decrease in amplitude with additional hydration. This pattern is hypothesized to signal the transport of water into the polymer matrix resulting in a reduced degree of phase separation. Coupled to these morphological changes, the enhanced proton transport characteristics and structural/mechanical stability for the block copolymer are hypothesized to be primarily due to the ordered structure of ionic clusters that create connected proton transport pathways while reducing swelling upon hydration. Interestingly, the random copolymer did not possess an ionomer peak at any of the hydration levels investigated, indicating a lack of any significant ionomer structure. The random copolymer also demonstrated higher proton conductivity than the block copolymer, which is opposite to the trend normally seen in polymer membranes. However, it has reduced structural/mechanical stability as compared to the block copolymer. In conclusion, this reduction in stability is due to the random morphology formed by entanglements of polymer chains and the adverse swelling characteristics upon hydration. Therefore, the block copolymer with its enhanced proton conductivity characteristics, as compared to Nafion, and favorable structural/mechanical stability, as compared to the random copolymer, represents a viable alternative to current proton exchange membranes.
Book Synopsis High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene Ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water Insoluble Zirconium Fillers by :
Download or read book High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene Ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water Insoluble Zirconium Fillers written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Our research group has been engaged in the past few years in the synthesis of biphenol based partially disulfonated poly(arylene ether sulfone) random copolymers as potential PEMs. This series of polymers are named as BPSH-xx, where BP stands for biphenol, S stands for sulfonated, H stands for acidified and xx represents the degree of disulfonation. All of these sulfonated copolymers phase separate to form nano scale hydrophilic and hydrophobic morphological domains. The hydrophilic phase containing the sulfonic acid moieties causes the copolymer to absorb water. Water confined in hydrophilic pores in concert with the sulfonic acid groups serve the critical function of proton (ion) conduction and water transport in these systems. Both Nafion and BPSH show high proton conductivity at fully hydrated conditions. However proton transport is especially limited at low hydration level for the BPSH random copolymer. It has been observed that the diffusion coefficients of both water and protons change with the water content of the pore. This change in proton and water transport mechanisms with hydration level has been attributed to the solvation of the acid groups and the amount of bound and bulk-like water within a pore. At low hydration levels most of the water is tightly associated with sulfonic groups and has a low diffusion coefficient. This tends to encourage isolated domain morphology. Thus, although there may be significant concentrations of protons, the transport is limited by the discontinuous morphological structure. Hence the challenge lies in how to modify the chemistry of the polymers to obtain significant protonic conductivity at low hydration levels. This may be possible if one can alter the chemical structure to synthesize nanophase separated ion containing block copolymers. Unlike the BPSH copolymers, where the sulfonic acid groups are randomly distributed along the chain, the multiblock copolymers will feature an ordered sequence of hydrophilic and hydrophobic segments. If, like in Nafion, connectivity is established between the hydrophilic domains in these multiblock copolymers, they will not need as much water, and hence will show much better protonic conductivity than the random copolymers (with similar degree of sulfonation, or IEC) at partially hydrated conditions. The goal of this research is to develop a material suitable for use as a polymer electrolyte membrane which by the year 2010 will meet all the performance requirements associated with fuel cell operation at high temperatures and low relative humidity, and will out-perform the present standard Nafion{reg_sign}. In particular, it is our objective to extend our previous research based on the use of thermally, oxidatively, and hydrolytically, ductile, high Tg ion containing polymers based on poly(arylene ethers) to the production of polymer electrolyte membranes which will meet all the performance requirements in addition to having an areal resistance of
Book Synopsis Examining Structure-Property Relationships of Proton Exchange Membranes Through the Study of Model Sulfonated Graft Copolymers by : Ching-Ching Ami Yang
Download or read book Examining Structure-Property Relationships of Proton Exchange Membranes Through the Study of Model Sulfonated Graft Copolymers written by Ching-Ching Ami Yang and published by . This book was released on 2014 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of polymer nanostructure on morphology, crystallinity, water sorption and proton conductivity was investigated using a model solid polymer electrolyte. Poly([vinylidene difluoride-co-chlorotrifluoroethylene]-graft-styrene) [P(VDF-co-CTFE)-g-PS], which consists of a hydrophobic, fluorous backbone and styrenic graft chains of varied length was synthesized with controlled chain architecture and chemical composition. The polystyrene graft chains were sulfonated to different degrees to provide three series of polymers with controlled ion exchange capacity (IEC). Due to chemical dissimilarity of the hydrophobic fluorous segments and the hydrophilic sulfonated polystyrene segments, the copolymers phase separate into ionic and non-ionic domains. The ionic domains allow transport of water and protons; the hydrophobic domains provide mechanical integrity, preventing the membranes from dissolving in water. The design of the model graft copolymers allows systematic examination of the effects of graft length and graft density on water sorption and proton conductivity. One of the major features of this work is that the sulfonated graft copolymers with shortest graft chains exhibit highest degree of crystallinity and highest PVDF content, which restrict excessive swelling and alleviate acid dilution, leading to a wider IEC operating range for high proton conductivity. Furthermore, the short graft copolymers allow access to very high IEC membranes that are insoluble in water. These short graft polymers with high IECs exhibit exceptionally high proton conduction under reduced humidity and elevated temperatures. In addition, for a given PVDF content, the lower graft density copolymers were observed to possess higher crystallinity and more contiguous PVDF domains that allow high IEC membranes to be prepared that possess lower degrees of swelling. Another important finding is that blending fully sulfonated graft copolymers with high molecular weight PVDF yields membranes with overall low IECs that exhibit highly localized ion content. This promotes the interconnection of ionic domains for effective proton transport while the more extended hydrophobic domains significantly reduce excessive swelling which serve to maintain the mechanical property of the membranes. This thesis describes a systematic approach, demonstrating the design, synthesis, characterization of model polymers, followed by the analysis of structure-property relationships in proton exchange membranes.
Book Synopsis Polymer Membranes for Fuel Cells by : Javaid Zaidi
Download or read book Polymer Membranes for Fuel Cells written by Javaid Zaidi and published by Springer Science & Business Media. This book was released on 2010-07-15 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the late-1960’s, perfluorosulfonic acid (PFSAs) ionomers have dominated the PEM fuel cell industry as the membrane material of choice. The “gold standard’ amongst the many variations that exist today has been, and to a great extent still is, DuPont’s Nafion® family of materials. However, there is significant concern in the industry that these materials will not meet the cost, performance, and durability requirementsnecessary to drive commercialization in key market segments – es- cially automotive. Indeed, Honda has already put fuel cell vehicles in the hands of real end users that have home-grown fuel cell stack technology incorporating hydrocarbon-based ionomers. “Polymer Membranes in Fuel Cells” takes an in-depth look at the new chem- tries and membrane technologies that have been developed over the years to address the concerns associated with the materials currently in use. Unlike the PFSAs, which were originally developed for the chlor-alkali industry, the more recent hydrocarbon and composite materials have been developed to meet the specific requirements of PEM Fuel Cells. Having said this, most of the work has been based on derivatives of known polymers, such as poly(ether-ether ketones), to ensure that the critical requirement of low cost is met. More aggressive operational requi- ments have also spurred the development on new materials; for example, the need for operation at higher temperature under low relative humidity has spawned the creation of a plethora of new polymers with potential application in PEM Fuel Cells.
Book Synopsis Materials for Use as Proton Conducting Membranes for Fuel Cells by :
Download or read book Materials for Use as Proton Conducting Membranes for Fuel Cells written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A family of polymers having pendent sulfonate moieties connected to polymeric main chain phenyl groups are described. These polymers are prepared by the steps of polymerization (using a monomer with a phenyl with an alkoxy substitution), deportation by converting the alkoxy to a hydroxyl, and functionalization of the polymer with a pendant sulfonate group. As an example, sulfonated poly(arylene ether sulfone) copolymers with pendent sulfonic acid groups are synthesized by the direct copolymerization of methoxy-containing poly(arylene ether sulfone)s, then converting the methoxy groups to the reactive hydroxyl form, and finally functionalizing the hydroxyl form with proton-conducting sites through nucleophilic substitution. The family of polymers may have application in proton exchange membranes and in other applications.
Book Synopsis Advanced Nanomaterials for Membrane Synthesis and Its Applications by : Woei Jye Lau
Download or read book Advanced Nanomaterials for Membrane Synthesis and Its Applications written by Woei Jye Lau and published by Elsevier. This book was released on 2018-11-21 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Nanomaterials for Membrane Synthesis and Its Applications provides the academic and industrial communities the most up-to-date information on the latest trends in membrane nanomaterials and membrane nanotechnology used in wastewater treatment, environmental technology and energy. The rapid advances in nanomaterials and nanotechnology development over the past decade have resulted in significant growth of the membrane business for various industrial processes, particularly in nanotechnology-based membrane processes. While membrane technology is increasingly being used for liquid and gas separations, it has great potential in a variety of additional applications. As the worldwide academic community has a strong interest in advanced membrane processes, particularly membrane nanotechnology for specific separations, this book provides a timely update on the topic. - Presents a unique focus on the use of advanced nanomaterials in membrane fabrication/modification, and in the description of membrane nanotechnologies, such as nanofiltration, thin film nanocomposites and nanofibers for various applications - Describes next generation membranes, providing first resource details on the development and commercialization stages of these new membranes - Represents the state-of-the-art on the use of nanomaterials in membrane science
Book Synopsis Synthetic Methods in Step-Growth Polymers by : Martin E. Rogers
Download or read book Synthetic Methods in Step-Growth Polymers written by Martin E. Rogers and published by John Wiley & Sons. This book was released on 2003-08-08 with total page 619 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alles über die Stufenwachstums-Polymerisation - von Syntheseverfahren und Reinigungsmethoden bis zur Charakterisierung der Produkte - finden Sie in diesem Buch. - bietet einen Ausblick auf zukünftige Trends - mit historischen Informationen - erläutert die Klassifikation von Stufenwachstumspolymeren
Book Synopsis Multiblock Copolymers Containing Hydrophobic and Hydrophilic Segments for Anion Exchange Membranes by : Derek J. Strasser
Download or read book Multiblock Copolymers Containing Hydrophobic and Hydrophilic Segments for Anion Exchange Membranes written by Derek J. Strasser and published by . This book was released on 2017 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis PEM Water Electrolysis by : Dmitri Bessarabov
Download or read book PEM Water Electrolysis written by Dmitri Bessarabov and published by Academic Press. This book was released on 2018-08-04 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Book Synopsis High Performance Polymers and Engineering Plastics by : Vikas Mittal
Download or read book High Performance Polymers and Engineering Plastics written by Vikas Mittal and published by John Wiley & Sons. This book was released on 2011-09-09 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes advances in synthesis, processing, and technology of environmentally friendly polymers generated from renewable resources. With contents based on a wide range of functional monomers and contributions from eminent researchers, this volume demonstrates the design, synthesis, properties and applications of plant oil based polymers, presenting an elaborate review of acid mediated polymerization techniques for the generation of green polymers. Chemical engineers are provided with state-of-the-art information that acts to further progress research in this direction.
Book Synopsis High Temperature Polymer Electrolyte Membrane Fuel Cells by : Qingfeng Li
Download or read book High Temperature Polymer Electrolyte Membrane Fuel Cells written by Qingfeng Li and published by Springer. This book was released on 2015-10-15 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters of the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept of and motivated extensive research activity in the field. The last 11 chapters summarize the state-of-the-art of technological development of high temperature-PEMFCs based on acid doped PBI membranes including catalysts, electrodes, MEAs, bipolar plates, modelling, stacking, diagnostics and applications.
