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Prevost, Valérie. "Contribution à l'élaboration de matériaux polymères conducteurs électroniques : étude et modélisation de la polymérisation de l'aniline et de sa copolymérisation avec des acides o-amino-phénoxyalcanesulfoniques." Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL046N.
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Dans le cadre du développement de matériaux polymères conducteurs électroniques, ces travaux visent, d'une part, l'élaboration d'un modèle de la polymérisation de l'aniline par couplage chimique oxydant (en milieu acide et en présence de persulfate d'ammonium), et d'autre part, son extension à la copolymérisation de l'aniline avec des acides o-amino-phénoxyalcanesulfoniques. Mise en place pour l'étude de l'influence des conditions opératoires (nature de l'oxydant, acidité du milieu, concentrations des réactifs,), la technique de suivi de l'avancement de la réaction par la mesure du potentiel redox du milieu a permis de mettre en évidence les étapes essentielles du processus de polymérisation. Le modèle global proposé prend en compte une étape lente d'initiation (dimérisation), une phase de propagation (caractérisée par l'autocatalyse par le polymère formé) et la dégradation du dimère (hydrolyse). L’optimisation des paramètres cinétiques et la validation du modèle sont réalisées à partir des courbes d'évolution de la conversion d'aniline, déterminées à l'issu du dosage par CPG du monomère résiduel. L’étude cinétique des copolymérisations de l'aniline avec les dérivés substitués par un groupement alkoxysulfonique montre que la réactivité des comonomères en présence est très différente selon le processus envisagé. À cause de l'encombrement stérique des substituant, la dimérisation implique obligatoirement une molécule d'aniline. Au cours de la phase de propagation, l'effet électrodonneur des substituant, abaissant le potentiel d'oxydation par rapport à celui de l'aniline, est favorable à l'attaque électrophile des macromolécules, et entraine une réactivité des dérivés très supérieure à celle de l'aniline. Les copolymères obtenus présentent vraisemblablement une structure séquencée. Les conductivités de ces copolymères autodopés sont comprises entre 10-⁴ et 1 S. Cm-1.
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Pinoche, Monique. "Transport facilité dans les membranes échangeuses d'ions : application à l'extraction du dioxyde de carbone d'un mélange gazeux par le transporteur éthylènediamine monoprotonée." Rouen, 1989. http://www.theses.fr/1989ROUES027.
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L'extraction d'un constituant d'un mélange gazeux peut être réalisée par couplage des phénomènes de diffusion et réaction à travers une membrane. Ce mode de transport a été appliqué à des membranes échangeuses d'ions dont les contre-ions, appelés transporteurs, réagissent réversiblement avec le substrat pour former un ou des complexes. Cette étude théorique a été appliquée au transport facilité du dioxyde de carbone par les ions éthylènediamines à travers différentes membranes échangeuses de cations (permion et nafion)
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Catonné, Jean-Claude. "Contribution à l'étude du défaut de sélectivité présenté par les membranes échangeuses d'anions, dans le cadre de leurs applications au traitement électrochimique de régénération des solutions aqueuses d'acides minéraux." Paris 6, 1986. http://www.theses.fr/1986PA066030.
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Essai d'identification de l'origine de la "fuite h+" et de celle des différentes sources susceptibles d'alimenter le mouvement d'eau au sein des membranes échangeuses d'anions, selon que le matériau est fortement ou non "élusterisé", puis d'établissement de l'existence d'une corrélation étroite entre l'intensité de fuite protonique et celle de la perméabilité osmotique des membranes (ainsi que le laisse prévoir la théorie de Gierke dans le cas des membranes échangeuses de cations). Et enfin, évaluation du rôle du champ électrique, ainsi que celui de la composition de l'électrolyte sur les résultats.
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Abdellatif, Mohamed Moustafa. "Poly(arylene ether)s with Truly Pendant Benzene Sulfonic Acid Groups." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1222544981.
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Roy, Choudhury Shreya. "Synthesis, Characterization and Structure - Property Relationships of Post - sulfonated Poly(arylene ether sulfone) Membranes for Water Desalination." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99381.
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Clean water is critical to the safety, security and survivability of humankind. Nearly 41% of the Earth's population lives in water-stressed areas, and water scarcity will be exacerbated by an increasing population. Over 96% of the total water is saline and only 0.8% is accessible fresh water. Thus, saltwater desalination has emerged as the key to tackle the problem of water scarcity. Our current work deals with the membrane process of reverse osmosis. Sulfonated polysulfones are a potential alternative to state-of-the-art thin film polyamides. Synthesized by step growth polymerization, polysulfone membranes have smooth surfaces and they are more chemically resistant relative to polyamides.
Previously studied sulfonated polysulfone membranes were synthesized by direct copolymerization of pre-disulfonated comonomer and the sulfonate ions were placed on adjacent rings of bisphenol moiety. This study focuses on placing the sulfonate ions differently along the polysulfone backbone on isolated rings of hydroquinone moiety, and on adjacent rings of biphenol moiety- and its effect on the transport and hydrated mechanical properties of the membranes. Selective post sulfonation of poly(arylene ether sulfone) in mild conditions was also found to be an effective way to strategically place the sulfonate ions along the backbone of the polymer chain without the need to synthesize a new monomer.
Hydroquinone based, amine terminated oligomers were synthesized with block molecular weights of 5000 and 10,000 g/mol. They were post-sulfonated and crosslinked at their termini with epoxy reagents. Such crosslinked and linear membranes had sulfonate ions on isolated rings of hydroquinone moiety. Synthesis and kinetics of controlled post-sulfonation of poly(arylene ether sulfones) that contained biphenol units were also reported. The sulfonation reaction proceeded only on the biphenol rings. The linear membranes had sulfonate ions on adjacent rings of biphenol moieties.
The tensile measurements were performed on the membranes under fully hydrated conditions. All membranes remained glassy at values of water uptake. It was found that elastic moduli and yield strengths in the hydroquinone- based linear and crosslinked membranes increased with decrease in water uptakes in the membranes. The effect of plasticization of water superseded the effect of block length and degree of sulfonation in the membranes. The highest elastic modulus of 1420 MPa at lowest water uptake of 18% was observed in cross linked membrane with 50% repeat units being sulfonated (50% repeat units contain hydroquinone)and target molecular weight of 5000 g/mol. However, the hydroquinone membranes broke at low strains of < 20%. The hydrated mechanical properties could be improved by replacing the hydroquinone with biphenol moieties. The biphenol based post-sulfonated membrane showed high elastic modulus that was comparable to the hydroquinone-based counterparts at similar values of water uptake. The biphenol based membrane broke at higher strains of >80%.
The post-sulfonated membranes- hydroquinone-based linear and crosslinked membranes and biphenol-based linear membranes had better transport properties than the previously studied sulfonated polysulfones that were synthesized by disulfonated comonomers.The post sulfonated hydroquinone-based membranes did not show a compromise in the rejection of monovalent ions in the presence of divalent ions in mixed feed water. The superior properties of the post-sulfonated membranes can potentially be attributed to the kinked backbone that potentially increased the free volume in the membranes and the sulfonate ions were spaced apart to potentially reduce their chelation with calcium (divalent) ions in mixed feed water. Interestingly, the biphenol based post-sulfonated membranes also did not have any compromise in the rejection of monovalent ions in the presence of divalent ions. This was potentially because the sulfonate ions were spaced far apart on the non-planar biphenol rings.PHD
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LI, XINDI. "MODIFICATION OF SULFONATED SYNDIOTACTIC POLYSTYRENE AEROGELS THROUGH IONIC INTERACTIONS." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525801145416997.
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Jameel, Dler Adil. "Electrical properties of sulfonated polyaniline (Span) and polyaniline (Pani) polymers grown on conventional and high index GaAs substrates." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/36040/.
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The electrical properties of sulfonated polyaniline (SPAN) and polyaniline (PANI) grown on both conventional (100) and high Miller index GaAs surfaces are investigated. These devices were electrically characterized using Current-Voltage (I-V), Capacitance-Voltage (C-V), Capacitance-Frequency (C-F), Capacitance-Conductance-Frequency (C-G-F), Deep Level Transient Spectroscopy (DLTS), and Laplace DLTS measurements in the temperature range 20 – 440 K. Electrically active defects are generated at/near the interface and away from the interface with energy levels deep in the bandgap of the materials. These defects considerably affect the electrical and optical properties of the devices. This thesis reports the effect of n-type GaAs substrate orientation, namely (100), (311)A and (311)B, on the electrical properties of sulfonated polyaniline (SPAN)/GaAs heterojunction devices. It was found that the interface state density (Dit) of SPAN/(311)B GaAs samples is lower than that of (100) and (311)A GaAs devices. This behaviour is attributed to the effect of crystallographic orientation of the substrates, and was confirmed by DLTS results as well. In addition, the inhomogeneity of the interface between various GaAs substrates and SPAN is investigated in terms of barrier height and ideality factor by performing I–V measurements at different temperatures (20–420 K). The I–V results indicate that the value of the rectification ratio (IF/IR) at 0.5 V is higher for SPAN/(311)B GaAs samples than for SPAN/(100) GaAs and SPAN/(311)A GaAs samples. Moreover, the barrier height decreases and the ideality factor increases with decreasing temperature for all three heterostructure devices. This thesis also reports an extensive study of the electrical properties of PANI/GaAs (organic-inorganic) hybrid heterojunctions. Polyaniline (PANI) thin films were deposited by a very simple technique on (100), (311)A and (311)B ntype Gallium Arsenide (GaAs) substrates to fabricate hybrid devices with excellent electrical properties. The DLTS and Laplace DLTS measurements illustrated that the number of defects at/very close to the interface region in PANI/(311)A GaAs samples is lower than those of PANI/(100) GaAs and PANI/(311)B GaAs samples. Moreover, the analysis of I–V characteristics based on the thermionic emission mechanism has shown a decrease of the barrier height and an increase of the ideality factor at lower temperatures for all the three hybrid devices. The interface states were analysed by series resistance obtained using the C–G–V methods. The interface state density (Dit) of PANI/(100) GaAs devices is approximately one and two order of magnitude higher than that of PANI/(311)B GaAs and PANI/(311)A GaAs devices, respectively. Additionally, the devices show excellent air stability, with rectification ratio values almost unaltered after two years of storage under ambient conditions, making the polyaniline an interesting conductor polymer for future devices applications.
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Shi, Ying. "High Temperature Shape Memory Polymers & Ionomer Modified Asphalts." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1374793580.
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Zhang, Huan. "Properties and Structures of Sulfonated Syndiotactic Polystyrene Aerogel and Syndiotactic Polystyrene/Silica Hybrid Aerogel." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1405298489.
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Zhang, Tianhong. "Synthesis, characterization and barrier properties of sulfone-containing polymers." Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1057587664.
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Cancouët, Patrick. "Synthèse et caractérisation de nouveaux polysiloxanes fonctionnalisés et propriétés biospécifiques." Paris 13, 1994. http://www.theses.fr/1994PA132017.
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Des polysiloxanes porteurs de fonctions arylsulfonate, alkylsulfonate et carboxylate ont été synthétisés afin d'obtenir des biomatériaux ayant des fonctions chimiques analogues à celles des glycosaminoglycanes, polysaccharides naturels ayant diverses propriétés biologiques (propriétés d'adhésion cellulaire, propriétés anticoagulantes). Nous avons étudié les étapes de synthèse de ces divers polysiloxanes. 1) des copolysiloxanes porteurs de fonctions hydrogenosilane (i) sont d'abord préparés par copolymerisation cationique d'octamethylcyclotetrasiloxane et de 1,3,5,7-tetramethylcyclotetrasiloxane en présence d'un agent télogène qui permet de contrôler la masse molaire. La répartition des différents motifs le long de la chaîne macromoléculaire, étudiée par RMN, est proche d'une répartition statistique. 2) des polysiloxanes porteurs de fonctions époxyde (II) sont obtenus par hydrosilylation de l'allylglycidylether par les fonctions hydrogenosilane du polysiloxane (i) en présence de h2ptcl6/6 h2o. Un mécanisme réactionnel a été propose pour expliquer l'ordre 1/2 en fonction silane, mis en évidence par l'étude cinétique. 3) des polysiloxanes porteurs de fonctions arylsulfonate (III) sont ensuite obtenus par réaction de la fonction phénol de l'hydroxybenzenesulfonate de sodium sur les fonctions époxyde du polysiloxane (II) en présence d'une amine tertiaire (dimethyloctylamine). Une étude cinétique de la réaction phenol-epoxyde a été réalisée par RMN et spectroscopie UV et un mécanisme réactionnel a été proposé. Des films de polyuréthane obtenus par réaction entre les fonctions hydroxyle résultant de l'ouverture du cycle époxyde et un polyisocyanate aliphatique présentent une absence de cytotoxicité et une activation de la croissance cellulaire (fibroblastes). 4) des polysiloxanes porteurs de fonctions alkylsulfonate (IV) ont été obtenus par réaction entre les fonctions époxyde d'un polysiloxane époxyde (II) et le bisulfite de sodium en présence d'un catalyseur de transfert de phase. Ces polymères présentent une activité anticoagulante très significative qui est fonction du taux de sulfonatation. 5) des polysiloxanes porteurs de fonctions carboxylate (v) ont également été préparés par hydrosilylation entre le pentene 4-oate de tertiobutyle et les fonctions hydrogenosilane du polysiloxane (i) en présence de h2ptcl6 h2o suivie d'une déprotection de l'acide carboxylique par l'acide chlorhydrique anhydre
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Huang, Chongwen. "Rheology of Oligomeric Sulfonated Polystyrene Ionomers." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1471281020.
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Blanco, Jean-François. "Elaboration et caractérisation de membranes de nanofiltration à base de polysulfone sulfonée. Transport d'espèces neutres et ioniques." Rouen, 2000. http://www.theses.fr/2000ROUES061.
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La nanofiltration (NF) est un nouveau procédé de filtration qui permet de séparer des solutés moléculaires et des sels contenus dans un milieu solvant. Les membranes synthétiques de NF, par leur faible coût et leur large domaine d'applications en séparation et en purification, offrent aux industriels une alternative intéressante pour le traitement d'eaux usées ou d'effluents contenant des composés à haute valeur ajoutée. Ce travail a pour objectif l'élaboration et la caractérisation de membranes de NF en polysulfone (Udel : PSU) ou polyéthersulfones (Victrex : PES ou Cardo : PESC) sulfonées pour la déionisation partielle et sélective de solutions salines à faible force ionique. La première partie de cette étude est consacrée à la synthèse des polymères sulfoniques par des voies classiques dans les solvants chlorés ou par des voies moins onéreuses dans les acides sulfuriques. La caractérisation des polymères obtenus présente une gamme étendue de degré de sulfonation qui permet l'inversion de la balance hydrophile-hydrophobe des polymères initiaux. Elle montre l'existence de compétition entre la réaction de sulfonation et des réactions de dégradations des polymères. Les membranes asymétriques sont préparées par la technique d'inversion de phases. La caractérisation (MEB et AFM) des structures permet de corréler les paramètres expérimentaux (nature du polymère, concentration et composition du collodion, température) aux mécanismes de formation des membranes obtenues. Les performances des membranes (densité de flux de perméat et taux de rétention R du soluté) sont déterminées par des expériences de NF portant sur des solutions d'espèces neutres ou ioniques. La membrane de PESC de plus haut degré de sulfonation présente la plus grande sélectivité (R(Na+)=20 % et R(Ca2+)=90%) pour des mélanges de cations de valence différente. Ces données mettent en évidence le phénomène d'exclusion dynamique en NF à travers des membranes ayant des pores chargés de la taille du nanomètre
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Pitia, Emmanuel Sokiri. "Composite Proton Exchange Membrane Based on Sulfonated Organic Nanoparticles." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1339277956.
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Cui, Xiaoyu. "POLYCATION REINFORCED SULFONATED SYDIOTACTIC POLYSTYRENE GELS& SELF-HEALING LATEX CONTAINING POLYELECTROLYTE MULTILAYERS." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1495204173832965.
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Dejeu, Jérôme. "Films de deux polymères auto-assemblés : chlorhydrate de polyallylamine (PAH) et polystyrène sulfonate de sodium (PSS) : mécanisme de croissance et stabilité." Besançon, 2007. http://www.theses.fr/2007BESA2005.
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Le mécanisme et la stabilité d’auto-assemblage de deux polyélectrolytes (PAH et PSS) en vue de la nano-encapsulation ont été essentiellement étudiés par réflectométrie laser à angle fixe. Cette technique se révèle très utile pour quantifier la masse de polymère adsorbé en fonction du temps sur un substrat. Dans un premier temps, plusieurs méthodes, de conversion du signal réflectométrique en quantité adsorbée, ont été présentées. Ainsi, ans le cas de film monocouche, une nouvelle approche de conversion des signaux est nécessaire afin de prendre en compte un fort changement d’indice de la solution dû à des concentrations de polymères importantes. Dans le cas de films auto-assemblés, le modèle consiste à considérer une couche adsorbée d’épaisseur et d’indice variant après chaque injection. La deuxième partie, a permis de proposer un mécanisme d’auto-assemblage de ces deux polyélectrolytes. Cette étude réalisée sur substrat plan, à l’aide de la réflectométrie et de l’AFM, met en évidence des différences de comportement de chaque polyélectrolyte. On a aussi eu recours à une étude sur colloïde pour montrer le rôle important des ions, le changement d’ionisation des polymères et le nombre de couches nécessaire à une couverture complète du substrat. Enfin, cette partie s’est terminée par l’étude de films très épais, constitués d’un nombre de couches allant jusqu’à 320, et nécessitant l’utilisation de techniques nouvelles dans ce domaine, le faisceau d’ions focalisé et la spectroscopie à décharge luminescente. La dernière partie a traité de la stabilité du film auto-assemblé lors de son rinçage dans des conditions différentes ou non de celles de la construction. Le dernier polyélectrolyte adsorbé et le nombre de couches déposées influent le comportement des films. Ces résultats permettent de prévoir les conditions de conservation de ces films ainsi que celles de déconstruction partielle ou totale en vue du relargage du principe actif contenu dans les capsulesThe growth mechanism and the stability of polyelectolyte films elaborated by multi-steps self association were investigated using principally fixed angle laser reflectometry. The first part of the investigation addressed the conversion of the reflectometric output into the deposited weight of polymer. In the case of a monolayer we have established the range of validity of a linear relationship between the deposited weight and the reflectometric output. In the case of a multilayer film we have used and explored a new approach developed in the laboratory allowing the determination of the stepwise change of the refractive index and the film thickness, leading eventually to the deposited weight. The second part of the work is dedicated to the experimental elaboration of films with the polyelectrolytes poly(allylamine,HCl) and poly(styrene sulfonate). The influence of the principal operational parameters was screened (pH, ionic strength, type of electrolytes, molecular weight of polymers, washing between deposition steps, etc). The charge balance and the incorporation of small ions were determined step by step. The elaboration of films on the flat silica substrate in the reflectometric cell was compared with that on colloidal silica. Complementary characterization of the polymer films were made with AFM and Focused ion beam imaging (FIB-SIM), which allowed the determination of the films morphology and roughness. Very thick films were constructed. A growth mechanism was proposed to explain the transition between an early stage (first steps), influenced by the property of the surface and later steps where the growth only depends on the interaction between the two polymers. Finally the stability of 1 to 5 bilayers films was examined upon change of the pH of the solution
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Daryaei, Amin. "Synthesis and Characterization of Linear and Crosslinked Sulfonated Poly(arylene ether sulfone)s: Hydrocarbon-based Copolymers as Ion Conductive Membranes for Electrochemical Systems." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/86439.
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Sulfonated poly(arylene ether sulfone)s as ion conductive copolymers have numerous potential applications. Membranes cast from these copolymers are desirable due to their good chemical and thermal stability, excellent mechanical strength, satisfactory conductivity, and excellent transport properties of water and ions. These copolymers can be used in a variety of topologies. Structure-property-performance relationships of these membranes as candidates for electrolysis of water for hydrogen production and for purification of water from dissolved ions have been studied.
Linear and multiblock sulfonated poly(arylene ether sulfone)s are potential alternative candidates to Nafion membranes for hydrogen gas production via electrolysis of water. In this investigation, these copolymers were prepared from the direct polymerization of di-sulfonated and non-sulfonated comonomers with bisphenol monomers. In systematic investigations, a series of copolymers with modified properties were synthesized and characterized by changing the ratio of the sulfonated/non-sulfonated comonomers in each reaction. These copolymers were investigated in terms of mechanical stability, proton conductivity and H2 gas permeability at a range of temperatures and under fully hydrated conditions.
A multiblock copolymer was synthesized and evaluated for its potential as membranes for electrolysis of water and for fuel cell applications. The multiblock copolymer contained some fluorinated repeat units in the hydrophobic blocks, and these were coupled with a fully disulfonated hydrophilic block prepared from 3,3'-disulfonate-4,4'-dichlorodiphenyl sulfone and biphenol. After annealing, the multiblock copolymer showed enhanced proton conductivity and a more ordered morphology in comparison to the random copolymer counterparts. At 90 oC and under fully hydrated conditions, improved proton conductivity and controlled H2 gas permeability was observed. Finally, the performance of the multiblock copolymer, which was measured as the ratio of proton conductivity to H2 gas permeability, was improved when compared to the state-of-the-art membrane, Nafion 212, by a factor of 3.
In another systematic study, two series of random copolymers were synthesized and characterized, and then cast into membranes to evaluate for electrolysis of water. One series contained solely hydroquinone as the phenolic monomer, while the second series contained a mixture of resorcinol and hydroquinone as phenolic comonomers. The polymers that contained only the hydroquinone monomer showed exceptionally good mechanical properties due to the para-substituted comonomer in the composition of the polymer. In the resorcinol-hydroquinone series, gas permeability was constrained due to the presence of 25% of the meta-substituted comonomer incorporated into its structure. Low gas permeability and high proton conductivity at elevated temperatures were obtained for both the linear random and multiblock copolymers. Performance of these copolymers was superior to Nafion at elevated temperatures (80-95°C). In order to enhance the durability of these materials in their hydrated states at elevated temperatures, the surfaces of these copolymer films were treated with fluorine gas. In comparison with pristine non-fluorinated membranes, the modified membranes showed decreased water uptake and longer durability in Fenton's reagent.
A series of linear and crosslinked copolymers were investigated with respect to their potential for use as membranes for desalination of water by electrodialysis and reverse osmosis. The crosslinked membranes were prepared by reacting controlled molecular weight, disulfonated oligomers that were terminated with meta-aminophenol with an epoxy reagent. The oligomers had systematically varied degrees of disulfonation and either 5000 or 10,000 Da controlled molecular weights. Membrane casting conditions were established to fabricate highly crosslinked systems with greater than 90% gel fractions. At such a high gel fraction, the water uptake of the crosslinked membranes was lower than that of the linear biphenol-based, disulfonated random copolymer with a similar IEC. Among these series of copolymers, it was shown that the crosslinked membranes cast from the oligomers with 50% degree of disulfonation and a molecular weight of 10,000 Da had the lowest salt permeability of 10-8 cm2/sec.
For desalination applications, a comonomer was synthesized with one sulfonate substituent on 4,4'-dichlorodiphenyl sulfone. This new monosulfonated comonomer allows for even distribution of the ions on the linear copolymer backbone, and this may be important for controlling ion transport. Mechanical tests were conducted on the membranes while they were submerged in a water bath. The ultimate strength of a fully hydrated copolymer with an IEC of 1.36 meq/g was approximately 60 MPa with an elongation at break of 160%. Moreover, in a monovalent/divalent mixed salt solution, the monosulfonated linear copolymer exhibited a constant Na+ passage of less than 1.0%.Ph. D.
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Elsen, Andrea M. "“One-Pot” Oligomeric A2 + B3 Approach to Branched Poly(arylene ether sulfone)s: Reactivity Ratio Controlled Polycondensation." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1279291050.
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Cai, Liang. "GRAFT COPOLYMER AEROGELS FROM SULFONATED SYNDIOTACTIC POLYSTYRENE FUNCTIONALIZED WITH A QUATERNARY PHOSPHONIUM-CONTAINING RAFT AGENT." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1468851884.
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Rasolovoahangy, Andriampanananjato. "Microlithographie : détermination de la composition de l'HPR-204. Formulation de résines homologues." Montpellier 2, 1992. http://www.theses.fr/1992MON20224.
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Pour ameliorer la performance des photoresists positifs actuels, nous avons envisage d'analyser la composition de la resine hpr-204 en vue d'elaborer des resines similaires. Compte tenu des donnees bibliographiques, des composes photosensibles et des novolaques non greffees et portant comme greffon un groupement 1-oxo 2-diazonaphtoquinone 5-sulfonyl ont ete prepares. Leurs caracteristiques physico-chimiques ont ete determinees par spectroscopies, par chromatographies et par analyses thermiques. Ce travail a permis de montrer qu'il etait possible de differencier une novolaque greffee d'un simple melange de novolaque et de composes de type 1-oxo 2-diazonaphtoquinone 5-sulfonate. Ce travail preliminaire a permis d'affirmer que l'hpr-204 est une resine qui renferme essentiellement une novolaque non greffee a base de meta et de para-cresol, avec des pourcentages eleves de pontage methyleniques en position ortho-ortho. De plus, ce photoresist renferme egalement comme composes photosensibles, des produits obtenus par esterification de la 2,3,4-trihydroxybenzophenone par la 5-chlorosulfonyl 1-oxo 2-diazonaphtoquinone. Le solvant utilise, qui constitue 72% en poids de la resine, est un melange d'acetate de cellosolve, d'acetate de n-butyle, de xylene et d'ethylbenzene. Compte tenu de ces resultats, nous avons alors elabore de nouvelles resines similaires. L'etude comparative des proprietes microlithographiques de ces resines et de l'hpr-204 a montre qu'il etait possible d'obtenir, dans certains cas, avec de telles resines originales de meilleures proprietes
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Planche, Jean-Pascal. "Nouveaux polymères sulfonés dérivés du polynorbornène." Lyon 1, 1985. http://www.theses.fr/1985LYO10512.
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Etude cinetique complete en solution de la sulfonatation du polynorbornene; la reaction a ete developpee a des etats plus concentres susceptibles de transposition industielle "en suspension" et en "masse". Analyse structurale par spectroscopie ir. Selon le taux de sulfonation, on peut distinguer 3 types de materiaux: ionomeres (10%), hydrophiles (50%), hydrosolubles(50%) dont les proprietes mecaniques, thermiques et thermodynamiques ont ete evaluees soit en solution, soit a l'etat solide. Comparaison avec des produits similaires et depot d'un brevet
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Omosa, Haron Moeti. "Studies on Several Diacetone-Glucose-derived Esters." Youngstown State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1628676922903541.
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Werry, Brian Scott. "Modifiable Poly(arylene ether)s and Hyperbranched Poly(esters)." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1187277614.
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Fichou, Swiecicka Joanna. "Synthèse de polymères à chaînes latérales perfluoroalkyles sulfonées pour la conception de membranes conductrices protoniques." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI116/document.
Full textAbstract:
Dans le cadre de ces travaux, l’objectif fixé était de développer des polymères aromatiques possédant des propriétés de conduction protonique. Pour y parvenir des motifs de type acide sulfonique ont été introduits le long des chaînes macromoléculaires. La méthodologie de synthèse de ces polymères qui a été choisie, consistait à polymériser des précurseurs contenant dans leur structure un motif perfluoroalkyle sulfoné. Quatre précurseurs originaux ont ainsi été initialement synthétisés. Différents polymères aromatiques ont été préparés à partir de ces précurseurs en faisant varier le taux de séquences perfluoroalkyles sulfonées. Ces polymères ont ensuite été mis en oeuvre sous la forme de membranes denses selon un procédé de coulée évaporation. A partir de ces membranes, des études de gonflement à l’eau et de conductivité ionique ont été réaliséesAs part of this work, the objective was to develop aromatic polymers with proton conduction properties. To achieve this, the sulfonic acid motifs were introduced along the macromolecular chains. The methodology of synthesis of these polymers was to polymerise the precursor containing in their structure a perfluoroalkyl sulfone moieties. Four novel precursors have been initially synthesized. Different aromatic polymers were prepared from these precursors by varying the rate of perfluoroalkyl sulfonated sequences. These polymers were then used in the form of dense membranes obtained by a casting process of evaporation. From these membranes, swelling studies in water and ionic conductivity were carried out
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Taeger, Antje. "Membranen aus [(A)n(B)m]x-Multiblockcopolymeren für den Einsatz in der Direkt-Methanol-Brennstoffzelle (DMFC)." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1136279464548-12309.
Full textAbstract:
Aramide and arylene ether multiblock copolymers of (AB)n-type with various degrees of sulfonation have been prepared for use in direct methanol fuel cellsAramid- und Arylethersulfon-Multiblockcopolymere vom Typ (AB)n mit unterschiedlichem Sulfonierungsgrad wurden hergestellt und hinsichtlich ihrer Eignung als Polymerelektrolyte in der Direkt-Methanol-Brennstoffzelle getestet
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Mathevet, Fabrice. "Cristaux liquides supramoléculaires exemple des alcanesulfonates et alkylbenzènesulfonates de guanidinium." Strasbourg 1, 2002. http://www.theses.fr/2002STR13142.
Full textAbstract:
Deux séries homologues d'alkylbenzènesulfonate et d'alcanesulfonate de guani-dinium à chaînes alkyle longues ont été synthétisées. Comme pressenti sur la base de considérations géométriques, ces composés générent à haute température des mésophases smectiques, ordonnées (SmO) et désordonnées (SmA). Leur polymor-phisme thermotrope a été analysé par microscopie optique en lumière polarisée, en-thalpimétrie différentielle et dilatométie. Leur structure cristallographique a été établie par diffraction des rayons X. La caractérisation détaillée des phases SmO, réussie grâce à la résolution des mailles cristallines, a permis de montrer que l'assemblage supramoléculaire des groupes ioniques, réalisé à l'état cristallin au moyen d'un ré-seau bidimensionnel de liaisons hydrogène, résiste à la fusion des chaînes alkyle qui se produit à haute température au passage dans l'état smectique. Cet assemblage supramoléculaire détermine l'organisation latérale des molécules dans les couches, aussi bien dans la phase cristalline que dans la phase SmO. La stabilité du réseau de liaisons hydrogène à haute température et la persistance de l'architecture supra-moléculaire dans les phases smectiques ont été confirmées par spectroscopie infra-rougeTwo homologous series of guanidinium alkylbenzenesulfonates and alcanesulfonates with long alkyl chains have been synthetised. As expected on the basis of purely geometrical considerations, these compounds give at high temperature ordered (SmO) and disordered (SmA) smectic mesophases. Their thermotropic polymorphism was investigated by polarized optical microscopy, differential scanning calorimetry, and dilatometry. Their crystallographic structure was determined by X-ray diffraction. The careful characterisation of the SmO phases, elucidated thanks to the resolution of the crystalline cell structure, revealed that the supramolecular assembly of the ionic groups, which is formed in the crystalline state by a 2D hydrogen bonded network, is able to outlast the melting of the alkyl chains in the smectic phase. This supramolecular assembly induces the lateral arrangement of molecules inside the layers not only in the crystalline state but also in the SmO phase. The stability of hydrogen-bond network and the persistence of supramolecular architecture in the smectic phases have been ascertained by infrared spectroscopy
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Neithikunta, Kavitha. "Synthesis and Characterization of Functionalized Poly(arylene ether sulfone)s using ClickChemistry." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1476628166464853.
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Neuendorf, Annette J., and n/a. "High Pressure Synthesis of Conducting Polymers." Griffith University. School of Science, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040218.112214.
Full textAbstract:
An experimental investigation of the high pressure synthesis of water soluble, self doping conducting polymers is presented. 2- And 3-aminobenzenesulfonic acid and the respective sodium sulfonates have been polymerised. Optimal polymerisation conditions have been determined with respect to yield, conductivity and molecular weight. Reaction parameters such as oxidant, pressure, catalysts, reaction time and temperature and the use of additives were investigated. The minimum pressure required for polymerisation was 7 kbar. An increase in pressure had a negligible effect on polymer characteristics. The polymers were generated in aqueous, non-acidic media, to ensure they were selfdoping when characterised. Conductivities of between 10-6 Scm-1 and 10-3 Scm-1 were measured. The sulfonate salts reacted faster than the sulfonic acids and for both a longer reaction time resulted in higher yields and conductivities. These polymers were completely water soluble, of high molecular weight and able to be cast as thin films. The arylamines 5- and 8-aminonaphthalene-2-sulfonic acid and their respective sodium sulfonates were polymerised at elevated pressure. The naphthalene sulfonate salts polymerised at atmospheric pressure, but displayed a higher molecular weight when reacted under pressure. Generally the naphthalene monomers reacted similarly to the benzene monomers, although there were some differences. Conductivity and yield decreased with increased reaction times and the use of 0.1M equivalents of ferrous sulfate had an negligible effect on the polymers. The polynaphthalenes were highly water soluble, self doping and had conductivities in the order 10-5 to 10-3 Scm-1. A measurement of the activation volume for the polymerisation of 2-methoxyaniline and sodium 8-aminonaphthalene-2-sulfonate was performed. These were determined to be -44 ± 3 cm3mol-1 and -62 ± 10 cm3mol-1 respectively. These large negative values are consistent with rate limiting monomer oxidation.
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Asti, Kevin Asti. "Evaluation of the Efficacy of Zinc Sulfonated EPDM Ionomer as an Impact Modifier for Polyamide 6." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1471710393.
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Garanin, Evgeny M. "Sulfonated (poly)arenes as low-humidity proton conducting materials for polymer electrolyte fuel cell membrane applications." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1310582597.
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Rhoden, Stephen. "Physicochemical and thermochemical properties of sulfonated poly(etheretherketone) electrolyte membranes." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4629.
Full textAbstract:
Fuel cells have long been seen as an alternative to combustion powered and diesel powered engines and turbines. Production of energy via a fuel cell conversion method can generate up to 60% efficiency in comparison to 30% using a combustion powered engine, with low co-production of harmful side-products. The polymer electrolyte membrane (PEM) adapted for the fuel cell application is one of the main components that determines the overall efficiency. This research project was focused towards novel PEMs, such as sulfonated poly(etheretherketone) or SPEEK, which are cost-efficient and robust with high proton conductivities under hydrated conditions. The degree of sulfonation (DS) of a particular SPEEK polymer determines the proton conducting ability, as well as the long term durability. For SPEEK with high DS, the proton conduction is facile, but the mechanical stability of the polymer decreases almost proportionally. While low DS SPEEK does not have sufficient sulfonic acid density for fast proton conduction in the membrane, the membrane keeps its mechanical integrity under fully saturated conditions. The main purpose of this work was to address both issues encountered with SPEEK sulfonated to low and high DS. The addition of both solid acids and synthetic cross-links were studied to address the main downfalls of the respective SPEEK polymers. Optimization of these techniques led to increased understanding of PEMs and notably better electrochemical performance of these fuel cell materials. Oxo-acids such as tungsten (VI) oxide (WO[sub3]) and phosphotungstic acid (PTA) have been identified as candidate materials for creating SPEEK composite membranes. The chemistry of these oxo-acids is well known, with their use as highly acidic catalyst centers adopted for countless homogeneous and heterogeneous, organic and inorganic reactions.; Uniform dispersion of WO[sub3] hydrate in SPEEK solution was done by a sol-gel process in which the filler particles were grown in an ionomer solution, cast and allowed to dry. PTA composites were made by adding the solid acid directly to a solution of the ionomer and casting. The latter casting was allowed to dry and Cs+- exchanged to stabilize the PTA from dissolution and leaching from the membrane. The chemical and physical properties of these membranes were characterized and evaluated using mainly conductometric and X-ray photoelectron spectroscopic methods. Composite SPEEK/ PTA membranes showed a 50% decrease in PEM resistance under hydrogen fuel cell testing conditions, while SPEEK/ WO[sub3] composites demonstrated a ten-fold increase in the membrane's in-plane proton conductivity. The chemical and physical properties of these composites changed with respect to their synthesis and fabrication procedures. This study will expound upon their relations.ID: 030422791; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2010.; Includes bibliographical references.
Ph.D.
Doctorate
Department of Chemistry
Sciences
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Hamza, Ali Abdalla. "Preparation and performance testing of sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) - polyethersulfone thin film composite membranes." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/9576.
Full textAbstract:
Thin film composite membranes were prepared by coating the surface of polyethersulfone ultrafilnation membranes with dilute solutions of sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) polymer. Poly(2,6-dimethyl-1,4-phenylene oxide) was first sulfonated to different degrees, thus obtaining polymers of different ion exchange capacities, from which the coating solutions in methanol or methanol/chloroform mixtures were prepared. The reverse osmosis performance of the thin film composite membranes was studied using electrolyte solutes of different valences and ionic radii. The effect of the solvent used for the preparation of the polymer solution for surface coating was also investigated through testing the performance of the composite membranes in separating different electrolyte solutions as well as by micrographic techniques using a Scanning Electron Microscope and an Atomic Force Microscope. It was found that the preparation of thin film composite membranes with high selectivity and high flux was possible by adjusting properly the ion exchange capacity and the solvent used in making the coating solution. It was also found that the membrane performance was governed primarily by the ion exchange reaction between the solute cation and the proton in-SO$\sb3\sp{-}$H$\sp{+},$ as well as by the Donnan equilibrium. An attempt was also made to investigate the effect of changing the microporous substrate of the thin film composite membrane on the membrane permeation rate and selectivity. The porosity and the structure of the substrate play a significant role in determining the performance of the composit membrane.
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Specklin, David. "Propriétés magnétiques et structurales de complexes moléculaires supportés par des ligands de type acyle-hydrazone." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF060/document.
Full textAbstract:
Ces travaux consistent en l’étude selon trois axes de la chimie de coordination des ligands de type acyle-hydrazone, faisant suite à l’isolation d’un complexe binucléaire de manganèse (III) portant un tel ligand, et montrant un fort couplage ferromagnétique. Le développement de leur chimie de coordination avec des éléments de la première série de transition a permis la synthèse de plusieurs complexes binucléaires, permettant d’étudier la relation entre les structures moléculaires de ces systèmes, et leurs propriétés magnétiques. En parallèle, une série de polymères de coordination de métaux alcalins et alcalino-terreux portant des ligands acyle-hydrazone fonctionnalisés par un groupement sulfonate a été étudiée. Enfin, la synthèse de deux ligands dérivés d’un anthracène est présentée, celle-ci est accompagnée d’une étude de leurs propriétés de coordinationThis work consists in the study of the coordination chemistry of acyl-hydrazone ligands, following the discovery of a manganese (III) dinuclear complex showing a strong ferromagnetic coupling. The development of the acyl-hydrazone coordination to first-row transitional metals resulted in several dinuclear complexes allowing the study of the relationship between their structural and magnetic properties. In a second part the study of several coordination polymers of alkali and alkali-earth metals bearing acyl-hydrazone ligands functionalized with a sulfonate group is presented. Finally the synthesis of two anthracene-based ligands is presented along a study of their coordination properties
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Buyukyagci, Arzu. "Synthesis And Characterization Of Monoacetylferrocene Added Sulfonated Polystyrene Ionomers." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/1108026/index.pdf.
Full textAbstract:
Incorporation of monoacetylferrocene to the sulfonated polystyrene
ionomers imparted some changes in the properties of sulfonated polystyrene.
Sulfonation was carried out by acetic anhydride and concentrated sulphuric acid.
The sulfonation reaction and the degree of sulfonation were determined by
analytical titration and adiabatic bomb calorimeter .
For this purpose, sulfonated polystyrene (SPS) samples with varying
percentages of sulfonation were prepared between 0.85% and 6.51%. Monoacetyl
ferrocene was used in equivalent amount of sulfonation through addition
procedure.
FTIR Spectroscopy was one of the major techniques used to support the
successful addition of AcFe to the SPS samples. Altering the sulfonation degree
did not change the characteristic peak positions, but increased the peak intensities
with increasing the degrees of sulfonation.
Mechanical properties of resultant polymers were investigated. As a result,
elastic modulus of polymers decreased by the amount of monoacetylferrocene.
Thermal characteristic were found by Differential Scanning Calorimeter
(DSC). Thermal analysis revealed that sulfonated polystyrene samples after
addition of monoacetylferrocene displayed lower values of Tg.
Microscopic analysis were made by Scanning Electron Microscopy (SEM)
and single phase for each sample was observed. Besides, energy dispersed micro
analysis showed an increase in the intensity of the iron (II) peaks that is related to
the amount of monoacetylferrocene added to the SPS samples.
Flame retardancy for each polymer was also examined and found that
addition of monoacetylferrocene to sulfonated polystyrene does not change the
Limiting Oxygen Index value (LOI)(17). However, LOI value for polystyrene is
18.
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Joseph, Ronald Matthew. "Synthesis and Characterization of High Performance Polymers for Gas Separation and Water Purification Membranes and as Interfacial Agents for Thermplastic Carbon Fiber Composites." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/96219.
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This dissertation focuses on the synthesis and characterization of high performance polymers, specifically polybenzimidazoles (PBIs) for gas separation applications and polyimides (PI) for water purification and as interfacial agents for thermoplastic carbon fiber composites.
Two methods for improving the gas transport properties (for H2/CO2 separation) of a tetraaminodiphenylsulfone (TADPS)-based polybenzimidazole were investigated. Low molecular weight poly(propylene carbonate) (PPC) and poly(ethylene oxide) (PEO) were incorporated as sacrificial additives that could be removed via a controlled heat treatment protocol. PBI films containing 7 and 11 wt% PPC (blend) and 13 wt% PEO (graft) were fabricated and the gas transport properties and mechanical properties after heat treatment were measured and compared to the PBI homopolymer. After heat treatment, the 7 wt% PPC blend exhibited the highest performance while retaining the toughness exhibited by the PBI homopolymer.
Novel sulfonated polyimides and their monomers were synthesized for use as interfacial agents and water purification membranes. Polyimides are high performance polymers that have high thermal, mechanical, and chemical stability. The objective was to assess structure-property relationships of novel sulfonated polyimides prepared by direct polymerization of the diamine monomers. A series of sulfonated polyimides was synthesized using an ester-acid polymerization method with varying degrees of sulfonation (20%, 30%, and 50% disulfonated and 50% and 100% monosulfonated polyimides). The results showed that the toughness of the polyimides in the fully hydrated state was much better than current commercial cation exchange membranes.
A 100% disulfonated polyimide (sPI) and poly(amic acid) salt (PAAS) using the same monomers used for the synthesis of Ultem® were utilized as suspending agents for the fabrication of coated sub-micron polyetherimide (PEI) particles. Sub-micron particles were obtained using 1 wt% PAAS and 4 wt% sPI to coat the PEI. The PEI particles were coupled onto ozone treated carbon fibers using a silane coupling agent. SEM images showed a significant amount of particle coating on the treated carbon fibers compared to the non-silane treated carbon fibers.PHD
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Sgreccia, Emanuela. "Proton conducting membranes based on sulfonated aromatic polymers for PEM fuel cells : synthesis and properties." Aix-Marseille 1, 2010. http://www.theses.fr/2010AIX11001.
Full textAbstract:
Les membranes à échange protonique, composants essentiels des piles à combustibles à membrane polymère (PEMFC) doivent présenter différentes propriétés comme stabilité morphologique, hydrolytique, mécanique et une conductivité adéquate à une température supérieure à 100°C et pour une humidité relative basse. Dans cette thèse, nous explorons deux stratégies différentes pour la synthèse de polymères conducteurs protoniques, basées sur des polymères aromatiques sulfonatés: la formation de matériaux hybrides organiques-inorganiques nanocomposites et la formation de liaisons réticulées inter-chaines suite à des traitements thermiques. L’utilisation de matériaux hybrides permet d’utiliser l’effet synergique due à la présence d’un polymère organique et d’une part inorganique. Nous avons en particulier utilisé un mélange constitué de S-PEEK à haut degré de sulfonation comme constituant principal et d’un polymère à base de PPSU contenant des groupements silanols comme constituant minoritaire. Le S-PEEK est utilisé pour garantir une haute conductivité, tandis que le Si-PPSU maintient une bonne stabilité mécanique (phase d’”ancrage”). Nous avons également étudié des composites hybrides à base de S-PEEK, dans lequel est dispersé du TiO2 fonctionnalisé. La seconde stratégie poursuivie, la synthèse de polymères réticulés, a également donné des résultats très positifs. En particulier, on observe, pour la première fois, que l’on peut obtenir des liaisons sulfones inter-chaines en utilisant des traitements thermiques adaptés en présence de DMSO comme solvant. On a démontré que les membranes ainsi obtenues sont en mesure de résister dans l’eau jusqu’à 145°C sans phénomènes importants de gonflement, maintenant la stabilité mécanique et une bonne conductivité. Les membranes sont caractérisées par de nombreuses techniques, dont l’analyse thermogravimétrique, les mesures mécaniques statiques et dynamiques, les mesures de sorption d’eau, par immersion et en phase vapeur, la spectroscopie IR et NMR, la spectroscopie d’impédance et l’analyse diélectriqueLe membrane a scambio protonico, componenti essenziali delle celle a combustibile ad elettrolita polimerico (PEMFCs), per poter essere utilizzate efficacemente devono esibire differenti proprietà come stabilità morfologica, idrolitica, meccanica ed adeguate proprietà di conducibilità a temperature superiori a 100 °C per bassi valori d’umidità relativa. Nella presente tesi sono state esplorate due diverse strategie, basate su polimeri solfonati aromatici, per la sintesi di polimeri conduttori protonici: la formazione di ibridi organici-inorganici nanocompositi e la formazione di legami reticolati inter-catena a seguito di trattamenti termici. L'impiego di materiali ibridi permette di sfruttare l'effetto sinergico dovuto alla contemporanea presenza di una componente organica, polimerica, e di una inorganica. In particolare si è utilizzata una miscela costituita dallo S-PEEK ad alto grado di solfonazione come composto base e da un polimero sililato a base di PPSU come componente minoritario. Lo S-PEEK viene utilizzato per garantire un’elevata conducibilità, mentre l’Si-PPSU garantisce una buona stabilità meccanica (fase “ancora”). Sono stati anche studiati composti nanocompositi ibridi a base di S-PEEK in cui è stata dispersa TiO2 funzionalizzata. Anche la seconda strategia seguita, la sintesi di composti reticolati, ha dato risultati molto positivi. In particolare si è osservato, per la prima volta, che potevano essere ottenuti legami solfone inter-catena tramite l’utilizzo di opportuni trattamenti termici in presenza di DMSO come solvente di casting. Si è dimostrato che le membrane così ottenute sono in grado di resistere in acqua fino a 145 °C senza dare importanti fenomeni di swelling, mantenendo la stabilità meccanica e buone proprietà di conducibilità. Le membrane sono state caratterizzate mediante l’utilizzo di molte tecniche, tra cui: l’analisi termogravimetrica, le misure meccaniche statiche e dinamiche, le misure di assorbimento d’acqua, sia per immersione, che in fase vapore, la spettroscopie IR ed NMR, la spettroscopia di impedenza e l’analisa dielettrica
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Guha, Thakurta Soma. "Anhydrous State Proton and Lithium Ion Conducting Solid Polymer Electrolytes Based on Sulfonated Bisphenol-A-Poly(Arylene Ethers)." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1239911460.
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Einsla, Brian Russel. "High Temperature Polymers for Proton Exchange Membrane Fuel Cells." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27320.
Full textAbstract:
Novel proton exchange membranes (PEMs) were investigated that show potential for operating at higher temperatures in both direct methanol (DMFC) and H2/air PEM fuel cells. The need for thermally stable polymers immediately suggests the possibility of heterocyclic polymers bearing appropriate ion conducting sites. Accordingly, monomers and random disulfonated poly(arylene ether) copolymers containing either naphthalimide, benzoxazole or benzimidazole moieties were synthesized via direct copolymerization. The ion exchange capacity (IEC) was varied by simply changing the ratio of disulfonated monomer to nonsulfonated monomer in the copolymerization step. Water uptake and proton conductivity of cast membranes increased with IEC. The water uptake of these heterocyclic copolymers was lower than that of comparable disulfonated poly(arylene ether) systems, which is a desirable improvement for PEMs. Membrane electrode assemblies were prepared and the initial fuel cell performance of the disulfonated polyimide and polybenzoxazole (PBO) copolymers was very promising at 80 C compared to the state-of-the-art PEM (Nafion®); nevertheless these membranes became brittle under operating conditions. Several series of poly(arylene ether)s based on disodium-3,3â -disulfonate-4,4â -dichlorodiphenylsulfone (S-DCDPS) and a benzimidazole-containing bisphenol were synthesized and afforded copolymers with enhanced stability. Selected properties of these membranes were compared to separately prepared miscible blends of disulfonated poly(arylene ether sulfone) copolymers and polybenzimidazole (PBI). Complexation of the sulfonic acid groups with the PBI structure reduced water swelling and proton conductivity.
The enhanced proton conductivity of Nafion® membranes has been proposed to be due to the aggregation of the highly acidic side-chain sulfonic acid sites to form ion channels. A series of side-chain sulfonated poly(arylene ether sulfone) copolymers based on methoxyhydroquinone was synthesized in order to investigate this possible advantage and to couple this with the excellent hydrolytic stability of poly(arylene ether)s. The methoxy groups were deprotected to afford reactive phenolic sites and nucleophilic substitution reactions with functional aryl sulfonates were used to prepare simple aryl or highly acidic fluorinated sulfonated copolymers. The proton conductivity and water sorption of the resulting copolymers increased with the ion exchange capacity, but changing the acidity of the sulfonic acid had no apparent effect.Ph. D.
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Yeniay, Secil. "Sulfonated Styrene-co-maleic Acid And Its Derivatives As Superplasticizers In Concrete." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609455/index.pdf.
Full textAbstract:
In the past three decades, a new group of concrete admixtures, termed &ldquosuperplasticizers&rdquo
, were introduced to the concrete industry. They have gained wide acceptance because of their many advantages. The addition of superplasticizers to concrete improves the workability and strength of concrete. In this study, the effect of the chemical structure of poly (4-styrenesulfonic acid-co-maleic acid) sodium salt (SSAMA), which contains both sulfonic and carboxylic acid groups, which is a new superplasticizer, was analyzed. Two different molecular weights of PEG (polyethylene glycol monomethyl ether) were grafted to this water-soluble copolymer at different weight compositions. The structures of synthesized copolymers were verified by FTIR and NMR analyses. The molecular weight difference of the grafted copolymers with different side chain lengths was determined by dilute solution viscosimetry. The effects of chemical structure of grafted copolymers on the fluidity of cement paste and the mechanical properties of the mortars were investigated. The zeta potential measurements revealed the interactions between the cement particles and polycarboxylate type superplasticizers. The maximum fluidity was achieved for the PEG grafted copolymer with the weight ratio 3:3. The mechanical properties of this copolymer showed the highest flexural and compressive strength compared to other copolymers. The addition of various Li salts to SSAMA affected the ionic medium, therefore, the dispersion performance of cement paste and the mechanical properties of the mortars improved. The mixture of LiCl: SSAMA in 1:1 mol ratio exhibited the maximum fluidity compared to other Li salts and their compositions. This mixture gave the highest flexural strength but the mixture of Li2CO3 in 1:1 composition gave the highest compressive strength in each salt mixtures.
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Lambert, James M. "Synthesis and basic characteristics of segmented poly(arylene ether sulfone)-poly(arylate) copolymers." Diss., This resource online, 1986. http://scholar.lib.vt.edu/theses/available/etd-07282008-135252/.
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Gandasasmita, Suryo. "Synthèse et électropolymérisation de monomères pyrroliques contenant des échangeurs de cations et des complexants macrocycliques : caractérisations des films polymères en présence de solutions ioniques." Montpellier 2, 2001. http://www.theses.fr/2001MON20124.
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Andrejevic, Marina. "Functionalized Sulfone and Sulfonamide Based Poly(arylene ether)s." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1402073837.
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Picker, Jesse L. "Routes to N-Heterocycle Functionalized Poly(arylene ether sulfone)s." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1409597075.
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Kasseh, Mohamed. "Interactions en phase aqueuse de copolymères acrylamide-co-2-acrylamido-2-méthyl propane sulfonate de sodium avec des sels d'ammoniums quaternaires alkylés en présence ou en absence de submicroparticules de silice." Aix-Marseille 3, 2002. http://www.theses.fr/2002AIX30027.
Full textAbstract:
Nous avons étudié les interactions de deux copolymères de l'acrylamide et du 2-acrylamido-2-méthyl propane sulfonate de sodium, l'AM-AMPS-20 (20% en moles) et l'AM-AMPS-5, avec les bromures de : -tetramethylammonium (TMAB),- décaméthylène bis-trimethylammonium (10(TA)2B2), -dodecylbenzyldimethylammonium (12FDAB). Les isothermes de complexation, les mesures rhéologiques, électrophorétiques et conductimétriques montrent que, contrairement au TMA+, le 12FDA+ et le 10(TA)2++ s'apparient avec les sulfonates des copolymères. Les associations de polyions complexés sont appréhendées par diffusion quasi-élastique de la lumière. La formation de micelles sur les polyions est décelée par spectroscopie de fluorescence du pyrène. L'adsorption de l'AM-AMPS-5 sur la silice en présence du 12FDAB est établie par l'isotherme d'adsorption mixte et visualisée par microscopie électronique à transmissionWe have studied the interactions of two copolymers of acrylamide and sodium acrylamido-2-methyl propane sulfonate, AM-AMPS-20 (20% in moles) and AM-AMPS-5, with the bromides of : -tetramethylammonium (TMAB), -decamethylene bis-trimethylammonium (10(TA)2B2), and -dodecylbenzyldimethylammonium (12FDAB). The complexation isotherms determined by selective permeation of a hollow fiber membrane, rheology, laser Doppler electrophoresis and conductivity measurements show that, in opposition to TMA+, 12FDA+ and 10(TA)2++ cations complex with sulfonates of both copolymers. Associations of polyions-12FDAB complexes are disclosed by dynamic light scattering. The onset of micelle formation on polyions is determined by pyrene fluorescence spectroscopy. Adsorption of AM-AMPS-5 onto colloidal silica in presence of 12FDAB is established through individual adsorption isotherms and visualised by transmission electron microscopy
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Kang, Junwon. "A NEW CLASS OF POLYELECTROLYTE;POLY( p-PHENYLENE DISULFONIC ACIDS)." online version, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1195481336.
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Hu, Ping. "Design of oxidation-sensitive polymer micelles for inflammation targeting." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/design-of-oxidationsensitive-polymer-micelles-for-inflammation-targeting(8ec02724-aeef-4ce8-ac2d-a3186de6267e).html.
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The research presented in this thesis focuses on the molecular design of an oxidation-sensitive nanocarrier and its enzyme conjugate with a view of their application in the field of biomaterials. I have polarised our attention on a specific class of polymers, the polysulfides, for their environmental responsiveness (towards oxidising substances, a condition often associated with inflammatory reactions), interesting physico-chemical properties, ease of the preparation and multiple possibilities for further modifications and bioconjugations, which are perfectly suitable for the development as systems for drug delivery applications. In this work we firstly have focused on the synthesis of amphiphilic poly(propylene sulfide)-poly(ethylene glycol) (PPS-PEG) block copolymers by employing vinyl sulfone as the functional group to link the blocks and modify the end of the PEG. This study was followed by an investigation of the macromolecular interchange and payload exchange of the formed polymeric micelles to understand the 'co-formulation' events, employing fluorophores (dansyl groups) and quenchers (dabsyl groups) either as terminal groups in macroamphiphiles or as encapsulated hydrophobic payloads. In another part of the work, I have developed a micellar system with which simultaneously to two of the most important ROS: superoxide and hydrogen peroxide, for inflammation-responsive drug release. The system is composed of superoxide dismutase (SOD) conjugated to oxidation-sensitive amphiphilic polysulfide/PEG block copolymers; the conjugate combines the SOD reactivity towards superoxide with that of hydrophobic thioethers towards hydrogen peroxide. Specifically, here we have demonstrated how this hybrid system can efficiently convert superoxide into hydrogen peroxide, which is then 'mopped-up' by the polysulfides. This mode of operation is functionally analogous to the SOD/catalase combination, with the advantage of being based on a single and more stable system.
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Finlay, Katherine A. "Characterization of Sulfonated Perfluorocyclobutane /Poly(Vinylidene Difluoride)-co-Hexafluoropropylene (PFCB/PVDF-HFP) Blends for Use as Proton Exchange Membranes." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/47475.
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The research herein focuses on the characterization of a PFCB/PVDF-HFP (70:30 wt:wt) blend fuel cell membrane including the constitutive and morphological properties, how these properties predict the stresses incurred under fuel cell operating conditions, and how these properties change over time under fuel cell operating conditions. Characterization was performed to mimic temperature and moisture conditions found in operating fuel cells to understand how these materials will behave in service. This included thermal and hygral expansion, mass uptake, and the stress relaxation modulus. These constitutive properties were chosen for characterization such that a model could be created to predict the stresses incurred during fuel cell operation, and examine how these stresses may change under different operating conditions and over time. Based on the results of this model, lifetime predictions were made resulting in recommendations to further extend the operating time of this membrane beyond the DOE 5000 hr requirement. Stress predictions are useful, however if the material properties are changing over time under the fuel cell operating conditions, they may no longer be valid. Therefore, PFCB/PVDF-HFP membranes were conditioned for different amounts of time under conditions similar to those commonly found in operating fuel cells. These conditioned membranes were then characterized and compared with solvent exchanged membranes, the same materials used for previous material characterization. The properties examined included stress relaxation modulus, bi-axial strength, mass uptake, water diffusion, and proton conductivity. To further understand any changes noted in these properties after different environmental exposures, morphological analysis was performed. This included small angle x-ray scattering, infrared spectroscopy, transmission electron microscopy, and differential scanning calorimetry.
It was initially found that the proton conductivity decreased severely when the material was immersed at high temperatures over short time periods. This was consistent with changes noted in other properties, and morphological analysis showed a decrease in the ionic network as well as an increase in the phase separation of the PFCB block copolymer as well as the PVDF-HFP crystallinity. These large morphological changes could be very detrimental while in service, resulting in early termination of the fuel cell. However, it was also noted that if these materials are annealed at high temperature (140"C), the negative property changes are abated. This abatement is again tied to the morphology of the material, as annealing the material at high temperature creates stronger physical crosslinks, and induces a small amount of chemical crosslinking via condensation of the sulfonic acid groups, thus allowing the stress predictions performed earlier to have greater validity. Therefore, it is important to not only understand the properties of a material during characterization, but also the underlying polymer structure, and how this structure can change over time, as all of these items control the long term material performance while in service.
Ph. D.
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VanHouten, Desmond J. "Benign Processing of High Performance Polymeric Foams of Poly(arylene ether sulfone)." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/30014.
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This work is concerned with the production of high performance polymer foams via a benign foaming process. The first goal of this project was to develop a process and the conditions necessary to produce a low density (>80% density reduction) foam from poly(arylene ether sulfone) (PAES). Water and supercritical carbon dioxide (scCO2) were used as the blowing agents in a one-step batch foaming process. Both water and scCO2 plasticize the PAES, allowing for precise control on both the foam morphology and the foam density. To optimize the foaming conditions, both thermogravimetric analysis and differential scanning calorimetery (DSC) were used to determine the solubility and the reduced glass transition temperature (Tg) due to plasticization of the polymer. It was determined that 2 hours was sufficient time to saturate the PAES with water and scCO2 when subjected to a temperature of 220 oC and 10.3 MPa of pressure. Under these conditions, a combination of 7.5% of water and scCO2 were able to diffuse into the PAES specimen, correlating to ~60 oC reduction in the Tg of the PAES. The combination of water and scCO2 produced foam with up to an 80% reduction in density. The compressive properties, tensile modulus, and impact strength of the foam were measured. The relative compressive properties were slightly lower than the commercially available structural foam made of poly(methacrylimide).
The second objective of the dissertation was to enhance the compressive properties of the PAES foam, without concern for the foam density. Foam was produced over a range of density, by controlling the cell size, in order to optimize the compressive properties. Carbon nanofibers (CNFs) were also added to the PAES matrix prior to foaming to both induce heterogeneous nucleation, which leads to smaller cell size, and to reinforce the cell walls. Dynamic mechanical thermal analysis (DMTA), on saturated CNF-PAES, was used to determine the reduced Tg due to plasticization and establish the temperature for pressure release during foaming. DMTA proved to be more effective than DSC in establishing quantitative results on the reduction in the Tg. The CNF-PAES foam produced had compressive properties up to 1.5 times the compressive properties of the PAES foam.Ph. D.
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Charif, Rodriguez Andrea Carolina. "New Applications for Linear and Arborescent Polyisobuylene-Based Thermoplastic Elastomers." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1425420506.
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Badami, Anand Shreyans. "Morphological and Structure-Property Analyses of Poly(arylene ether sulfone)-Based Random and Multiblock Copolymers for Fuel Cells." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29469.
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The commercialization of proton exchange membrane (PEM) fuel cells depends largely upon the development of PEMs whose properties are enhanced over current perfluorinated sulfonic acid PEMs. Understanding how a PEMâ s molecular weight and morphology affect its relevant performance properties is essential to this effort. Changes in molecular weight were found to have little effect on the phase separated morphologies, water uptake, and proton conductivities of random copolymers. Changes in block length, however, have a pronounced effect on multiblock copolymers, affecting surface and bulk morphologies, water uptake, proton conductivity, and hydrolytic stability, suggesting that multiblock copolymer PEM properties may be optimized by changes in morphology.
A major goal of current proton exchange membrane fuel cell research involves developing high temperature membranes that can operate at ~120 °C and low humidites. Multiblock copolymers synthesized from 100% disulfonated poly(arylene ether sulfone) (BPSH100) and naphthalene polyimide (PI) oligomers may be an alternative. At block lengths of ~15 kg/mol they displayed no morphological changes up to 120 °C or even higher. Water desorption was observed to decrease with increasing block length. The copolymers exhibited little to no water loss during a 200 °C isotherm in contrast to random BPSH copolymers and Nafion. A BPSH100-PI multiblock copolymer with large block length appears to have morphological stability and retain water at temperatures exceeding 120 °C, suggesting its candidacy as a high temperature PEM.
A growing number of alternative PEM research efforts involve multiblock copolymer chemistries, but little emphasis is placed on the methods used to couple the oligomers. Fluorinated linkage groups can help increase block efficiency during coupling, but their effect on a PEM is not well-known. The choice of linkage type, hexafluorobenzene (HFB) vs. decafluorobiphenyl (DFBP), appears to have small but observable influences on multiblock copolymers with disulfonated and unsulfonated poly(arylene ether sulfone) oligomers. DFBP linkages promote greater phase separation than HFB linkages, resulting in increased stiffness, decreased ductility, and increased proton conductivity at low humidities. DFBP linkages also promote more surface enrichment of fluorine, causing changes in surface morphology and slightly increased water desorption, but determining the impact on actual fuel cell performance requires further research.Ph. D.