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You searched for subject:(Perfluorinated ionomer). Showing records 1 – 3 of 3 total matches.

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Colorado School of Mines

1. Divekar, Ashutosh G. Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices.

Degree: PhD, Chemical and Biological Engineering, 2020, Colorado School of Mines

After decades of dedicated efforts in research and development of the polymer electrolyte membranes for electrochemical conversion devices, the technology is nearing their large-scale commercialization. Improvements like utilization of thin mechanically supported membranes (< 15 μm), advanced Pt catalysts with enhanced activity have made the proton-exchange membrane class of polymers very attractive for vehicular fuel cell and other electrochemical conversion applications. However, with the increasing energy demand for the rapidly growing population high performing commercial devices with non-precious catalysts need further attention. Anion exchange membrane polymers perfectly fit this description due to its compatibility with the cheaper electrochemical catalysts. In this work, the potential of novel perfluorinated anion exchange membranes primarily for low-temperature fuel cell applications were tested. Three iterations of polymer membranes with a PTFE backbone were electrochemically, physiochemically, and morphologically characterized to conclude that the six-carbon alkyl spacer chain is the most promising candidate with a high ionic (OH-) conductivity. Ex-situ characterization of this class of polymers was performed to understand the interaction of the hydroxyl charge carrier with the atmospheric CO2 in the ambient air as in a commercial fuel cell device, ambient air is used as an oxidant. It was concluded that the CO2 not only interacts with the ionic domains of the polymer but also hampers the crystallinity of the backbone which could potentially lead to mechanical failures while operating for longer durations. From the knowledge gained from this study, a standard fuel cell device was tested to report the highest air-fed anion exchange membrane fuel cell performance to date (446 mW cm-2). For the first time, the segmented fuel cell hardware was used to understand the spatial differences in the anion exchange membrane fuel cell performance due to the variation in humidification, fuel or oxidant starvation and the durability issues. Over several days of operation, it was found that the cell degrades primarily in the feed inlet section due to difference in the hydration or water accumulation over the channel length. FTIR analysis was performed to prove that the chemical functionality of the membrane changes due to the fuel cell operation. The catalyst-ionomer interface was investigated using polymer dispersion spin-coated on model Si and Ag substrates. From the grazing incident x-ray scattering study, phenomenon like parallel polymer chain alignment with respect to the surface at a higher ionomer thickness and their variation with hydration and type of substrate was investigated. With increasing thickness, the film formation undergoes two transition regimes: formation of crystalline polymer domains followed by intra-molecular alignment of CF2 units within the polymer chain. It was also found that the silver surface is interacting strongly with the polymer. From the knowledge gained, it is recommended to design… Advisors/Committee Members: Herring, Andrew M. (advisor), Koh, Carolyn A. (Carolyn Ann) (committee member), Krebs, Melissa D. (committee member), Samaniuk, Joseph R. (committee member), Pivovar, Bryan S. (committee member), Trewyn, Brian (committee member).

Subjects/Keywords: catalyst-ionomer interaction; fuel cells; segmented fuel cell; CO2 absorption; anion exchange membranes; perfluorinated polymer

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Divekar, A. G. (2020). Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/174176

Chicago Manual of Style (16th Edition):

Divekar, Ashutosh G. “Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices.” 2020. Doctoral Dissertation, Colorado School of Mines. Accessed August 06, 2020. http://hdl.handle.net/11124/174176.

MLA Handbook (7th Edition):

Divekar, Ashutosh G. “Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices.” 2020. Web. 06 Aug 2020.

Vancouver:

Divekar AG. Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2020. [cited 2020 Aug 06]. Available from: http://hdl.handle.net/11124/174176.

Council of Science Editors:

Divekar AG. Advanced perfluorinated anion exchange membrane polymers and their issues in electrochemical conversion devices. [Doctoral Dissertation]. Colorado School of Mines; 2020. Available from: http://hdl.handle.net/11124/174176


Université Montpellier II

2. Gao, Hongrong. Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells.

Degree: Docteur es, Chimie organique, minérale, industrielle, 2010, Université Montpellier II

Ce travail décrit le développement de membranes réticulées et de membranes composites inorganique-organique basées sur des polymères perfluorosulfoniques (PFSA) à chaîne longue (LSC) et courte (SSC) et à faible masse équivalente, pour application dans une pile à combustible fonctionnant à moyenne température et à faible humidité relative. Des membranes (LSC-PFSA) réticulées par des groupements sulfonimide ont été préparées à partir de membranes fonctionnalisées par des groupements fluorure de sulfonyle. Les membranes réticulées de type SSC-PFSA ont été préparées à partir d'un polymère à chaînes 2-bromo-1,1,2,2-tetrafluoroéthoxy pendantes et réticulables, par traitement thermique pour former des ponts perfluoro. Les membranes préparées ont été caractérisées par spectroscopies IR, Raman, RMN et XPS, par MEB-EDX et ATG. Les membranes de LSC-PFSA et SSC-PFSA réticulées présentent une stabilité dimensionnelle accrue et une meilleure performance en pile à combustible hydrogène-oxygène jusqu'à 110°C que celles des membranes de PFSA non modifiées. Une procédure d'échange ionique/précipitation a été utilisée pour la préparation de systèmes composites à partir de membranes de LSC-PFSA et SSC-PFSA. Plusieurs techniques ont été utilisées pour caractériser les matériaux préparés. Les membranes de type SSC-PFSA-ZrP présentent une morphologie distincte, et différente de celle des membranes LSC-PFSA-ZrP. En pile à combustible, ces membranes composites autorisent une température de fonctionnement plus élevée et une humidité relative plus faible, que les membranes non modifiées.

The objective of this research was to develop cross-linked and composite inorganic-organic membranes based on long and short side chain (LSC, SSC) perfluorosulfonic acid (PFSA) polymers with low equivalent weight/high ion exchange capacity for operation at medium temperature and low relative humidity in proton exchange membrane fuel cells. Covalently cross-linked LSC-PFSA membranes were prepared from sulfonyl fluoride form membranes by reaction with an ammonium base followed by thermal processing to give cross-linking through sulfonimide groups. Covalently cross-linked SSC-PFSA membranes were prepared by formation of perfluoro-cross-links under thermal treatment of solution cast polymers containing cross-linkable 2-bromo-1,1,2,2-tetrafluoroethoxy side chains. Evidence for cross-linking was provided by IR, Raman, NMR and XPS spectroscopies, SEM-EDX, tensile testing and TGA. Cross-linked LSC and SSC-PFSA membranes have increased dimensional stability and improved performance in a single hydrogen-oxygen cell fuel up to 110°C compared with the corresponding non-cross-linked membranes. Composite PFSA-zirconium phosphate membranes, based on LSC and SSC PFSA (or cross-linked PFSA) membranes were prepared using an ion exchange/precipitation procedure. The physical properties of LSC-PFSA-ZrP and SSC-PFSA-ZrP have been compared and the morphology of the composite membranes shown to differ in SSC and LSC membranes. Composite membranes enabled fuel cell operation at…

Advisors/Committee Members: Rozière, Jacques (thesis director), Zhang, Yongming (thesis director).

Subjects/Keywords: Pile à combustible; Electrolyte polymère; Membranes réticulées et composites; Membranes ionomères perfluorées; Phosphate de zirconium; Pile à combustible moyenne température; Proton electrolyte membrane fuel cells; Cross-linked and composite membranes; Polymer electrolyte; Perfluorinated ionomer membranes; Zirconium phosphate; Medium temperature fuel cell

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gao, H. (2010). Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells. (Doctoral Dissertation). Université Montpellier II. Retrieved from http://www.theses.fr/2010MON20236

Chicago Manual of Style (16th Edition):

Gao, Hongrong. “Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells.” 2010. Doctoral Dissertation, Université Montpellier II. Accessed August 06, 2020. http://www.theses.fr/2010MON20236.

MLA Handbook (7th Edition):

Gao, Hongrong. “Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells.” 2010. Web. 06 Aug 2020.

Vancouver:

Gao H. Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells. [Internet] [Doctoral dissertation]. Université Montpellier II; 2010. [cited 2020 Aug 06]. Available from: http://www.theses.fr/2010MON20236.

Council of Science Editors:

Gao H. Stabilisation des Membranes Perfluorosulfoniques par Réticulation et Développement de Membranes Composites Inorganique-organique. Application aux Piles à Combustible à Moyenne Température. : Stabilisation of Perfluorosulfonic Acid Membranes by Cross-linking and Inorganic-organic Composite Formation. Application in Medium Temperature Proton Exchange Membrane Fuel Cells. [Doctoral Dissertation]. Université Montpellier II; 2010. Available from: http://www.theses.fr/2010MON20236

3. Thiam, Amadou. Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery.

Degree: Docteur es, Matériaux, mécanique, génie civil, électrochimie, 2015, Université Grenoble Alpes (ComUE)

Le but de cette thèse était de développer de nouveaux électrolytes polymères pour une application batteries lithium métal polymère. Le premier volet concerne le développement des réseaux semi-interpénétrés à base de POE et d'un polycondensat. Ces types d'électrolytes ont permis de d'améliorer les propriétés mécaniques et les conductivités à haute et basse température. L'ajout de NCC comme renfort sur ces réseaux semi-interpénétrés a permis d'atteindre propriétés physico-chimiques intéressantes et des durées de vie élevées. De plus l'hydrogénation du polycondensat permettant de moduler sont taux de réticulation a permis d'obtenir un électrolyte (en présence du LiTFSI) présentant des conductivités de 1S.cm-1 à 90°C pour un rapport O/Li=20 et O/Li=30 avec une tenue mécanique de 0,5MPa jusqu'à 100°C. Dans le second volet une série de sels de lithium à anion organique a été synthétisée et caractérisée. Ces sels de lithium présentent des bonnes stabilités électrochimiques, thermiques et des conductivités cationiques parfois plus élevées que LITFSI en milieu polymère. Le dernier volet concerne la synthèse et la caractérisation physico-chimique des nouveaux ionomères perfluoré. Ces nouveaux ionomères à conduction cationique unipolaire sont obtenus à partir de monomères aromatiques porteurs de fonctions ioniques ayant une forte aptitude à la dissociation et des nombres de transport cationique proche de 1 à 70°C.

The aim of this thesis was to develop new polymer electrolytes for application of lithium metal polymer batteries. The first part concerns the development of semi-interpenetrating networks based on POE and a polycondensat. These types of electrolytes made it possible to improve the mechanical properties and conductivity at high and low temperatures. The addition of NCC as a reinforcement on the semi-interpenetrating network has led to interesting physicochemical properties and high cycle life for batteries.The partial hydrogenation of the polycondensat allowing the modulation of the reticulation ratio has allow to elaborate as an electrolyte (in the presence of LiTFSI) exhibiting 1S.cm-1 conductivities at 90 ° C for a ratio O/Li=20 and O/Li=30 with a mechanical strength of 0.5MPa to 100 ° C. In the second part a range of lithium with organic anion was synthesized and characterized. These lithium salts show good electrochemical and thermal stability, whereas ionics conductivities are sometimes higher than LiTFSI in polymer medium. The last part concerns the synthesis and physicochemical characterization of new perfluorinated ionomers. These new cationic ionomers with a unipolar conduction are obtained from aromatic monomers carriers ionic functional having a high ability to dissociation and cation transport numbers close to 1 at 70 ° C.

Advisors/Committee Members: Sanchez, Jean-Yves (thesis director), Iojoiu, Cristina (thesis director), Leprêtre, Jean-Claude (thesis director).

Subjects/Keywords: Electrolyte polymère; Nanocristaux de cellulose; Sel de lithium; Ionomère perfluoré; Hydrogénation; Réseaux semi-interpénétrés; Polycondensation; Nombre de transport; Polymer electrolyte; Cellulose nanocrystals; Lithum salt; Hydrogenation; Semi-interpenetrating networks; Polycondensation; Perfluorinated ionomer; Transport number; 620

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Thiam, A. (2015). Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery. (Doctoral Dissertation). Université Grenoble Alpes (ComUE). Retrieved from http://www.theses.fr/2015GREAI068

Chicago Manual of Style (16th Edition):

Thiam, Amadou. “Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery.” 2015. Doctoral Dissertation, Université Grenoble Alpes (ComUE). Accessed August 06, 2020. http://www.theses.fr/2015GREAI068.

MLA Handbook (7th Edition):

Thiam, Amadou. “Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery.” 2015. Web. 06 Aug 2020.

Vancouver:

Thiam A. Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery. [Internet] [Doctoral dissertation]. Université Grenoble Alpes (ComUE); 2015. [cited 2020 Aug 06]. Available from: http://www.theses.fr/2015GREAI068.

Council of Science Editors:

Thiam A. Nouvelles générations d'électrolyte pour batterie lithium polymère : News generations of electrolyte for lithium polymer battery. [Doctoral Dissertation]. Université Grenoble Alpes (ComUE); 2015. Available from: http://www.theses.fr/2015GREAI068

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