Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 121-127).

Στόχος της μεταπτυχιακής διατριβής αποτέλεσε η πειραματική μελέτη φαινομένων μεταφοράς μάζας από υγρά μη υδατικής φάσης (NAPLs) σε δισδιάστατα πορώδη δοκίμια. Τα υγρά μη υδατικής φάσης αποτελούνται από υδρογονάνθρακες οι οποίοι διαλύονται μερικώς στο νερό. Αποτελούν τη συχνότερα εμφανιζόμενη πηγή μόλυνσης των υπόγειων υδροφορέων και είναι ιδιαίτερα επιβλαβή για τον άνθρωπο. Ο κύριος διαχωρισμός των NAPLs σε κατηγορίες γίνεται με βάση την πυκνότητά τους σε σύγκριση με αυτή του νερού. Έτσι, υπάρχουν τα Light NAPLs (LNAPLs), τα οποία είναι ελαφρύτερα από το νερό με αποτέλεσμα να επιπλέουν στην επιφάνειά του και τα Dense NAPLs (DNAPLs), τα οποία είναι βαρύτερα από το νερό και διαπερνούν τη μάζα του μέχρι να συναντήσουν κάποιο αδιαπέραστο στρώμα. Η πειραματική διάταξη που χρησιμοποιήθηκε αποτελούνταν από γυάλινα δισδιάστατα πορώδη δοκίμια που είχαν κατασκευαστεί με τη λιθογραφική μέθοδο. Με τη βοήθεια αντλίας τα δοκίμια τροφοδοτούνταν με σταθερή παροχή και σε κατάλληλη χρονική στιγμή γινόταν η εισαγωγή του ρύπου στο δοκίμιο. Στη συνέχεια με τη βοήθεια φωτογραφικής μηχανής λαμβάνονταν στιγμιότυπα σε καθορισμένες χρονικές στιγμές και με γραφικές μεθόδους υπολογιζόταν η μεταφορά μάζας. Στο πρώτο κεφάλαιο, περιέχονται εισαγωγικά στοιχεία για τη δομή και τη φύση των υγρών μη υδατικής φάσης καθώς και οι επιπτώσεις τους στο περιβάλλον. Επίσης, γίνεται μια σύντομη αναφορά στο φαινόμενο της διαχύσεως και στο πρώτο πείραμα που παρατηρήθηκε η διάχυση από τον Dalton και περιγράφεται με συντομία το πείραμα που διεξήχθη. Στο δεύτερο κεφάλαιο, γίνεται εκτενής περιγραφή όλων των στοιχείων των υγρών μη υδατικής φάσης και αναλύεται η κίνηση των υγρών αυτών σε όλα τα είδη εδάφους. Επίσης, εξηγείται η διαφορετική συμπεριφορά που αυτά εμφανίζουν στα διάφορα μέσα με βάση τις φυσικές τους ιδιότητες και επίσης παρουσιάζονται οι πρώτες μαθηματικές σχέσεις που δικαιολογούν την κίνησή τους αυτή. Στο τέλος του κεφαλαίο αναφέρονται και χημικές διεργασίες που συμβαίνουν στο υπέδαφος και επηρεάζουν την κίνηση των NAPLs. Στο τρίτο κεφάλαιο περιγράφεται το φαινόμενο μεταφοράς μάζας στο νερό αλλά και σε πορώδη μέσα. Αναφέρονται και περιγράφονται οι σημαντικότεροι και απαραίτητοι τύποι που περιγράφουν τη μεταφορά μάζας και αναλύονται όλοι οι όροι που παίρνουν μέρος στη σύνταξη των τύπων αυτών. Τέλος, αναφέρονται κάποια πειράματα στα οποία χρησιμοποιήθηκαν οι τύποι που περιέχονται στη θεωρία. Στο τέταρτο κεφάλαιο, περιγράφεται η προετοιμασία της πειραματικής διαδικασίας και αναφέρεται ο τεχνικός εξοπλισμός που χρησιμοποιήθηκε για τη διεξαγωγή της. Περιγράφονται όλα τα στάδια του πειράματος με λεπτομέρειες στις διάφορες μεθόδους που χρησιμοποιήθηκαν για τη κατασκευή και τον υπολογισμό των ιδιότητων των δοκιμίων. Επίσης, γίνεται περιγραφή της λειτουργίας του προγράμματος Comsol που χρησιμοποιήθηκε κατά το σχεδιασμό των δοκιμίων. Στο πέμπτο κεφάλαιο, παρουσιάζονται τα αποτελέσματα της πειραματικής διαδικασίας σε μορφή πινάκων και διαγραμμάτων. Τα αποτελέσματα αναλύονται και περιγράφονται με λεπτομέρεια προβλήματα που προέκυψαν κατά τη διεξαγωγή των πειραμάτων. Τέλος εξάγονται συμπεράσματα και γίνονται υποδείξεις για την περαιτέρω διερεύνηση του φαινομένου. / The aim of this Master thesis was the experimental study of mass transfer phenomena of non-aqueous phase liquids (NAPLs) in two-dimensional porous specimens. The liquid non-aqueous phase consisting of hydrocarbons which partially dissolve in the water. Are the most frequently occurring source of contamination of aquifers and is particularly harmful to humans. The main distinction of NAPLs into categories is based on the density compared to that of water. Thus, there are the Light NAPLs (LNAPLs), which is lighter than water so that float on the surface and Dense NAPLs (DNAPLs), which are heavier than water and penetrate the mass of up to meet a impermeable layer . The experimental setup used consisted of two-dimensional porous glass specimens were manufactured with lithographic method. With the pump cores fed with a constant flow and at an appropriate time was the introduction of the pollutant in the essay. Then with the help of camera footage taken at fixed times and graphical methods estimated the mass transfer. In the first chapter, contained introduction to the structure and nature of the non-aqueous phase liquids and their impact on the environment. Also, there is a brief reference to the effect of diffusion in the first experiment observed the diffusion of the Dalton and briefly describes the experiment conducted. The second chapter is a detailed description of all elements of non-aqueous phase liquids and analyzed the movement of fluids across all kinds of terrain. It also explains the different behavior they show in various media based on physical properties and also presents the first mathematical relationships that justify this movement. At the end of the chapter lists and chemical processes occurring in the soil and affect the movement of NAPLs. The third chapter describes the phenomenon of mass transfer in water and in porous media. Listed and described the most important and necessary formulas describing mass transfer and analyze all terms that take part in the preparation of these types. Finally, some experiments indicated that used types contained in the theory. The fourth chapter describes the preparation of the experimental procedure and specifying the equipment used to conduct it. Describes all stages of the experiment in detail the various methods used to construct and calculate the properties of the samples. Also, there is a description of the operation of the program Comsol used in the design of essays. The fifth chapter presents the results of the experimental procedure in the form of tables and diagrams. The results are analyzed and described in detail problems encountered in conducting the experiments. Finally conclusions are drawn and suggestions are made for further investigation of the phenomenon.

Στην παρούσα εργασία μελετήθηκαν φυσικά πηκτώματα κατά συστάδων συμπολυμερών σε ιοντικό υγρό. Τα συμπολυμερή που μελετήθηκαν ήταν το τρισυσταδικό συμπολυμερές πολυ(αιθυλενοξείδιο)-πολυ(στυρόλιο)-πολυ(αιθυλενοξείδιο) (PEO-PS-PEO) και το αστεροειδές συμπολυμερές πολυ(στυρόλιο)-πολυ(αιθυλενοξείδιο) (PS10PEO10) στο ιοντικό υγρό εξαφθοροφωσφορούχο 1-βουτυλο-3-μεθυλιμιδαζόλιο [BMIM][PF6], το οποίο είναι "καλός" διαλύτης για το PEO και "κακός" διαλύτης για το PS. Αρχικά πραγματοποιήθηκε μοριακός χαρακτηρισμός των συμπολυμερών PEO-PS-PEO και PS10PEO10 μέσω των τεχνικών χρωματογραφίας αποκλεισμού μεγεθών (SEC) και της φασματοσκοπίας πυρηνικού μαγνητικού συντονισμού (1H-NMR). Στη συνέχεια πραγματοποιήθηκε η μελέτη των συμπολυμερών σε αραιά διαλύματα μέσω των τεχνικών της δυναμικής σκέδασης φωτός (DLS) και της ιξωδομετρίας. Παρατηρήθηκε πως τα συμπολυμερή PEO-PS-PEO και PS10PEO10 δημιουργούν πολυμοριακά και μονομοριακά "μαλακά" νανοσωματίδια μικκυλιακού τύπου, αντίστοιχα. Από τη DLS προσδιορίστηκε η υδροδυναμική ακτίνα, Rh, των σωματιδίων. Μέσω της τεχνικής της ιξωδομετρίας AMVn υπολογίστηκε η κρίσιμη συγκέντρωση επικάλυψης, c*, στην οποία τα σωματίδια αρχίζουν να εφάπτονται μεταξύ τους. Σε υψηλές συγκεντρώσεις των πολυμερών παρατηρείται η δημιουργία φυσικών πηκτωμάτων λόγω της πλήρωσης του όγκου του διαλύματος από τα σωματίδια. Μέσω ρεολογικών μελετών προσδιορίστηκε η κρίσιμη συγκέντρωση σχηματισμού πηκτώματος, cgel. Παρατηρήθηκε μεγάλη εξάρτηση του σχετικού ιξώδους από τη συγκέντρωση του συμπολυμερούς καθώς και η αύξηση της ισχύος (μέτρου αποθήκευσης) και του χρόνου χαλάρωσης των φυσικών πηκτωμάτων με την αύξηση της συγκέντρωσης. Τέλος, πραγματοποιήθηκε σύγκριση μεταξύ των συστημάτων PEO-PS-PEO/[BMIM][PF6] και PS10PEO10/[BMIM][PF6]. Διαπιστώθηκε πως το PS10PEO10 παρουσιάζει μεγαλύτερη cgel από το PEO-PS-PEO λόγω της μικρότερης πυκνότητας των αλυσίδων στην κορώνα του αστεροειδούς από αυτή του τρισυσταδικού με αποτέλεσμα τα σωματίδια του αστεροειδούς να διεισδύουν πολύ περισσότερο μεταξύ τους για να επιτευχθεί το φαινόμενο του συνωστισμού. / In the present study the properties of physical gels formed by block copolymers in an ionic liquid were studied. The triblock poly(ethylene oxide)-poly(styrene)-poly(ethylene oxide) (PEO-PS-PEO) and the star polystyrene-polyethylene (PS10PEO10) copolymers were studied in 1-butyl-3-methylimadazolium hexafluapophoshate, [BMIM][PF6], which is a good solvent for the PEO blocks and bad solvent for the PS blocks. Initially, the copolymers were characterized by size exclusion chromatography (SEC) and neutron magnetic resonance (1H-NMR). At a next step the study of the polymers in dilute solutions was followed by dynamic light scattering (DLS) and AMVn viscometry. It was found that PEO-PS-PEO and PS10PEO10 self assemble into multimolecular and monomolecular, micellar type soft nanoparticles, respectively. The size of the particles was calculated by DLS. From the AMVn viscometry, the critical overlap concentration at which the formed nanoparticles start adhering to each other, c*, was calculated. At high polymer concentrations, the formation of gels was observed which was due to the jamming of the particles in the total volume of the solution. Through rheological studies, the critical gelation concentration, cgel, was determined. Above cgel a dramatic viscosity rise was observed. At the same time, the storage modulus Go and the relaxation time τR of the system increased also with increasing concentration. Finally, the comparison between the PEO-PS-PEO/[BMIM][PF6] and PS10PEO10/[BMIM][PF6] systems was discussed. It was concluded that the PS10PEO10 copolymer exhibits a higher value of cgel than that of PEO-PS-PEO copolymer due to the lower density of the chains in the corona of the star nanoparticles.

Ionic liquids (ILs) are nowadays a large and widely explored class of ionic compounds that melt below 100 °C. Due to their attractive properties, ILs are now of growing interests in a variety of inorganic materials preparation. However, most studies have put much focus on the description of new synthetic strategies. The chemical reactivity of ILs in the reactions is often neglected. In this dissertation, a series of metal chalcogenides were synthesized using the decompositions of ILs. The role or chemical reactivity of ILs in the reactions was demonstrated in detail. The hierarchical desert-rose-like SrTiO3 particles have been successfully prepared based on an ethylene glycol (EG) mediated one-pot IL-assisted solvothermal synthetic route. The used basic ionic liquid tetrabutylammonium hydroxide (TBAH) serves as an alkaline source and can also replace EG as the sole solvent to synthesize polyhedral SrTiO3, showing “all-in-one” solvent and reactant. A series of metal sulfides, such as Sb2S3, Bi2S3, PbS, CuS, Ag2S, ZnS, and CdS have been obtained from a choline chloride/thioacetamide based deep eutectic solvent (DES, an IL analog solvent) by a simple and general synthetic method. The reaction mainly proceeds in two steps: i) the dispersion of metal salts in the DES and the formation of a metal-DES complex, and ii) the decomposition of the metal-DES complex and formation of the final products. In addition, the chemical reactivity of phosphonium based ILs with selenium and tellurium at above 220 °C was systematically investigated by a series of dissolution experiments, tracking the solute selenium and tellurium species by nuclear magnetic resonance (NMR). NMR results clearly indicate some common decomposition mechanisms for quaternary phosphonium ILs at a relatively high temperature in the presence of selenium or tellurium. The decomposition of the quaternary phosphonium cations should proceed by an elimination of one alkyl substituent via an SN2 reaction, forming the respective trialkylphosphane selenides or tellurides in the presence of selenium or tellurium, which is then responsible for the genuine dissolution of selenium or tellurium. However, in the case of tellurium, the dissolution behavior is much more complicated compared to that of selenium. The coupling of P and Te which indicates a P–Te bond formation is only observed in the NMR spectra when a sufficient amount of tellurium (e.g. Te : IL = 1 : 1) is provided. The existence of a parallel-competitive IL decomposition route besides the SN2 reaction is regarded as the side reaction for the dissolution of tellurium. This may at least partially explain the relatively lower solubility of tellurium in phosphonium based ILs compared to that of selenium.

Les terres rares (TR) sont aujourd’hui les « vitamines » des nouvelles technologies, elles se retrouvent dans tous les objets technologiques du quotidien et contribuent notablement au développement d’énergies vertes principalement par l’intermédiaire d’aimants permanents à base de terres rares (APTR). Ces derniers, de type NdFeB ou SmCo, représentent actuellement plus de 50 % du marché des TR et offrent un fort potentiel de recyclage. La présente étude se concentre sur le recyclage et la valorisation des APTR, principalement grâce au développement de l’électrochimie en milieu liquide ionique (LI) qui permet d’atteindre les potentiels de réduction des TR (< -2 V vs. ENH). Samarium, néodyme, dysprosium, praséodyme et cobalt ont effectivement été électrodéposés dans [C1C4Pyrr][Tf2N] suivant une méthode potentiométrique à 25 °C et sur une électrode de carbone vitreux.Deux méthodes globales de recyclage sont finalement proposées et ont été appliquées à des APTR industriels. La première est entièrement électrochimique. Elle est basée sur une phase d’électrodissolution de l’APTR dans le LI puis d’une électrodéposition sélective permettant de récupérer les métaux de transition. Une électrodéposition des TR est ensuite envisageable. La deuxième méthode s’appuie sur une lixiviation acide afin de séparer efficacement les métaux de transition des TR grâce à la formation de sels phosphatés. Une dissolution des sels obtenus dans un LI permettrait ensuite d’électrodéposer les ions métalliques. / Rare earth elements (REE) are currently essential for new technologies development; from everyday life objects to green energies devices, they are especially used in permanent magnets. NdFeB and SmCo permanent magnets represent more than 50% of the REE market and offer a high recycling opportunity. The present study focuses on their recycling, mainly via electrochemistry in ionic liquid medium (IL), which enables to reach the reduction potentials of REE (< -2 V vs. ENH).Samarium, neodymium, dysprosium, praseodymium and cobalt were successfully electrodeposited in [C1C4Pyrr] [Tf2N] according to a potentiometric method at 25 ° C and on a glassy carbon electrode.Two general recycling methods are finally proposed and have been applied to industrial permanent magnets. The first uses only electrochemistry and is based on a first magnet electrodissolution step in the IL followed by a selective electroplating to recover the transition metals. Electrodeposition of REE could then be possible. The second method starts by an acid leaching of the magnet in order to efficiently separate the transition metals from REE via the formation of phosphate salts. Dissolution of the salts obtained in LI would then enable to electrodeposit the metal ions.

No fim do século XX cresceu o interesse por materiais com potencial para aplicação na área da nanotecnologia. Um destes materiais é o grafeno (alótropo do carbono da espessura de um átomo), indicado para aplicações que exploram desde propriedades ópticas até mecânicas. Todavia, os métodos de produção estabelecidos até o momento geram normalmente um produto com alto grau de defeitos estruturais. Por isso, o objetivo deste estudo foi desenvolver um método mais brando para obtenção de grafeno, por meio do desenrolamento de nanotubos de carbono (NTC) de parede múltipla na presença de líquidos iônicos (LI) (que possuem caráter lubrificante e estabilizador) e adicioná-lo à resina epoxídica para avaliar seu efeito nas propriedades do nanocompósito. A metodologia consistiu em definir a rota a que a mistura NTC:LI (bis(trifluorometanosulfonil)imidato de 1-n-butil-3-metilimidazólio – BMImNTf2), na proporção 1:10, deveria ser submetida e depois avaliar variações para validação do método (alteração de temperatura, solventes – LI BMImCl e tolueno e nanocarga – grafite). As misturas de grafeno-NTC/LI produzidas foram adicionadas na proporção de 0,1% em massa de grafeno-NTC à resina epoxídica. A caracterização das misturas se deu pelas técnicas de microscopia eletrônica de transmissão (MET), espectroscopia Raman e microscopia de força atômica (AFM), e dos nanocompósitos, também por microscopia eletrônica de varredura (MEV), análise termogravimétrica (TGA), calorimetria diferencial exploratória (DSC), infravermelho (IV) análise dinâmico-mecânica (DMA) e ensaios mecânicos. A morfologia observada em MET e AFM evidenciou que a rota em que a mistura permaneceu 3 h em aquecimento e agitação magnética sob vácuo e 3 h sob sonificação resultou em grafeno de algumas camadas. Os resultados de Raman mostraram que foi produzido grafeno de boa qualidade, baseando-se na razão ID/IG. Nos nanocompósitos, confirmou-se que BMImNTf2 mantém as folhas de grafeno abertas. Já com BMImCl a morfologia dos NTC permanece inalterada, mas seu grau de emaranhamento é diminuído pela ação lubrificante deste LI, o que reflete em melhoria na resistência ao impacto. Os NTC sem a presença de um LI de forma geral não conferiram melhoria à matriz polimérica (ex: queda de 35% na dureza). / In the late twentieth century, the interest in materials with potential application in the nanotechnology´s field has increased. One of these materials is graphene (carbon allotrope of a single atom thickness), suitable for applications, which exploit properties such as optical or mechanical. However, the methods developed up to now to obtain graphene usually generate a product with high degree of structural defects. Therefore, the aim of this study was to produce graphene sheets through a milder route of unrolling multi-walled carbon nanotubes (CNT) in ionic liquids (IL; which have a lubricating and stabilizing character) and to add it to an epoxy resin to evaluate its effect on the nanocomposite properties. The methodology consisted of defining the route through which the 1:10 mixture of CNT:IL (1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate - BMImNTf2) should be submitted, and then evaluate possible variations for validating the method (change in temperature, solvents - toluene and IL BMImCl and nanofiller - graphite). The produced graphene-CNT/IL mixtures were added at 0.1% by weight of graphene-CNT to epoxy resin. Characterization of the graphene/IL mixtures was done by transmission electron microscopy (TEM), Raman spectroscopy and atomic force microscopy (AFM), and the nanocomposites also by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamical mechanical analysis (DMA) and mechanical tests. The morphology observed using TEM and AFM showed that the route based on 3 h under heating, stirring and vacuum, followed by 3 h of sonication leads to CNT unrolling. Raman spectra showed that the produced graphene was of good quality, based on the low ID/IG ratio. In the nanocomposites, CNT unrolling was confirmed when IL BMImNTf2 was used, yielding reasonable property improvements. In the case of IL BMImCl, the unrolling of the CNT did not occur, but the lubricant effect of the IL decreased the degree of entanglement, which increased its impact strength. Differently, the non-treated CNT generally reduced the properties of the polymer matrix, e.g. a 35% drop in hardness.

Os líquidos iônicos são uma das principais apostas para revolucionar a química no século XXI. Em geral, apresentam propriedades como baixa pressão de vapor, alta estabilidade térmica, e ampla existência liquida e outras que os tornam interessantes para aplicações como solventes para extração, meio reacional e como meio catalítico. Estas propriedades permitem a redução da geração de efluentes industriais, o que os torna potenciais solventes verdes. O interesse recente aumentou a quantidade de ânions e cátions disponíveis para formar líquidos iônicos. Essa maior diversidade por um lado aumenta o potencial de aplicação industrial dos líquidos iônicos, mas por outro aumenta a carga de trabalho para obter as propriedades necessárias para projeto industrial destas novas substâncias. Métodos preditivos podem ser utilizados para evitar a grande demanda de ensaios experimentais para obter essas propriedades. Entretanto modelos puramente preditivos, como o COSMO-RS, usualmente não obtém uma acurácia adequada para o uso industrial. Modelos que fazem uso de dados experimentais de misturas para estimar seus parâmetros, como o UNIFAC (Do) e o F-SAC, são predominantes na indústria. Esses modelos, que são modelos de coeficiente de atividade, permitem o cálculo de equilíbrio de fases e outras propriedades termodinâmicas. Este trabalho teve como objetivo o desenvolvimento do modelo F-SAC para líquidos iônicos. Baseado em trabalhos anteriores, foram reestimados os parâmetros dos grupos de líquidos iônicos já existentes e adicionados novos grupos de cátions e ânions. Também foram geradas as primeiras curvas de equilíbrio líquido-vapor de misturas contendo líquidos iônicos com o F-SAC. De forma geral, para os 1-alquil-3-etil-imidazólios, foi obtido um R2 de 0.9794 e o valor de AAD de 0.1721 para 1514 misturas com o modelo F-SAC, superior ao encontrado para o UNIFAC (Do). Para o piridínio e o pirrolidínio o F-SAC obteve, respectivamente, um R2 de 0.9281 e 0.9837 e um valor de AAD de 0.2749 e 0.0962. Com este trabalho é possível formar 24 diferentes líquidos iônicos base com o uso de 33 parâmetros eletrostáticos estimados e 22 parâmetros geométricos no F-SAC. Para o mesmo objetivo o modelo UNIFAC (Do) necessitaria de 180 parâmetros binários e 26 parâmetros individuais – todos estimados. Ou seja, o F-SAC, nesse caso, precisou estimar apenas 27% do número de parâmetros que o UNIFAC (Do). / Ionic Liquids are one of the most promising fields to revolutionize chemistry in the 21st century. In general, they show properties like negligible vapor pressure, high thermal stability, wide liquid existence turn them interesting for applications as solvents for extraction, as reactional and catalytic media. These properties allow a reduction in industrial effluent production, making them eligible green solvents. Recent inteerest expanded the number of anions and cations available to compose Ionic. This great diversity enhances the industrial application potential of Ionic Liquids, while increases the workload needed for obtaining properties of these new substances needed for industrial project. Predictive methods can used to avoid the demand of experiments to obtain these properties. Purely predictive methods, as COSMO-RS, are usually not accurate enough for industrial use. Models use experimental data from mixtures for parameter estimation like UNIFAC (Do) and F-SAC, are predominant in the industry. Activity coefficient models like these allow the solving of phase equilibria and other thermodynamic properties. This work aimed at developing the F-SAC model for Ionic Liquids. Based on previous works, the already existing parameters for Ionic Liquid groups were reestimated and new cation and anion groups were added. In addition, the first vapor-liquid equilibrium curves for mixtures containing Ionic Liquids were created for the F-SAC model. For 1-alkyl-3-ethyl-imidazoliums, an overall R2 of 0.9794 and AAD of 0.1721 for 1514 mixtures was obtained, superior to UNIFAC (Do) values. For pyridinium and pyrrolidinium, F-SAC achieved, respectively, R2 of 0.9281 and 0.9837 and AAD of 0.2749 and 0.0962. With this work is possible to form 24 different base Ionic Liquids with 33 estimated electrostatic parameters and 22 geometric parameters with F-SAC. For the same purpose, UNIFAC (Do) would need 180 binary parameters and 23 individual parameters – all estimated. For this particular case the F-SAC model needed to estimate only 27% of the parameter number UNIFAC (Do) needed.

Current problems on the interaction of complex liquids (i.e. droplets or foams) with complex surfaces (i.e. soft deformable or porous surfaces) are addressed in the following areas: (1) wetting of deformable substrates and surface forces, (2) kinetics of wetting and spreading of non-Newtonian liquids over porous substrates, (3) kinetics of spreading of non-Newtonian solutions over hair, (4) free drainage of foams produced from non-Newtonian solutions, and (5) foam drainage placed on porous substrates. Equilibrium of liquid droplets on deformable substrates was investigated and the effect of disjoining pressure action in the vicinity of the apparent three phase contact line was taken into account. It was proven that the deformation of soft solids is determined by the action of surface forces inside the transition zone. Spreading/imbibition of blood, which is a power law shear thinning non-Newtonian liquid, over a dry porous layer was investigated from both theoretical and experimental points of view. It was found that blood droplet spreading/imbibition over porous substrates shows two different behaviours: (i) partial wetting case with three subsequent stages: initial fast spreading, constant maximum droplet base and the shrinkage of the droplet base; (ii) complete wetting case with only two stages: initial fast spreading and the shrinkage of the droplet base. The wetting of hair tresses by aqueous solutions of two commercially available polymers, AculynTM 22 (A22) and AculynTM 33 (A33) was investigated experimentally. Both A22 and A33 solutions demonstrate well pronounced shear thinning behaviour. Initial contact angle of the A22 and A33 solutions on hair tresses was about 100o. The A22 droplets remained on the hair tress after spreading for at least half an hour. However, a fast penetration of the A33 droplets inside the hair tresses was observed when advancing contact angle in the course of spreading reached a critical value of about 60o. This could be explained by Cassie-Wenzel wetting transition which is caused by filling the pores inside the porous media by liquid. The influence of non-Newtonian rheology of A22 and A33 solutions on foam drainage was also investigated experimentally and a new theory of foam drainage was presented for the case of free drainage. For lowly viscous polymeric solutions and under the assumption of rigid surface of the Plateau border, the predicted values of the time evolution of the foam height and liquid content were in good agreement with the experimental data. However, in the case of highly viscous solutions an interfacial mobility at the surface of the Plateau border has to be taken into account. A completely new theory of foam drainage placed on porous substrate was developed. It was found that there are three different regimes of the process: (i) a rapid imbibition, the imbibition into the porous substrate dominates as compared with the foam drainage; (ii) an intermediate imbibition, that is, the imbibition into the porous substrate and the rate of drainage are comparable; (iii) a slow imbibition, the rate of drainage inside the foam is higher than the imbibition into the porous substrate for a period of time and a free liquid layer is formed over the porous substrate.

A novel free radical-based substitution reaction was developed for grafting aromatic/heteroaromatic compounds to perfluorosulfonic acid polymers (PFSAs). Two proton-exchange membranes perfluorobenzoic acid (PFBA) and perfluorobenzenesulfonic acid (PFBSA)—were synthesized for proton-exchange membrane fuel cells via the free radical-based reaction. The physical properties, in-plane ionic conductivities and fuel cell performance of two membranes were investigated. They exhibited different electrochemical and physical properties, possibly due to the formation of unique dimerized/trimerized structure of –CO2H groups in the PFBA membrane. A free radical-based thermolytic reaction under a high temperature (180 oC)/pressure (1000 psi) condition in the presence of TFA and hydrogen peroxide is first demonstrated. A novel perfluorotetrafluoroaniline (PFTFAn) polymer was synthesized from PFSA and 2,3,5,6-tetrafluoroaniline in one step via the thermolytic reaction. After doping H2SO4 in the PFTFAn polymer, a new conjugated acid membrane (H2SO4-doped PFTFAn) was obtained. The H2SO4-doped PFTFAn membrane displayed better chemical stability and mechanical properties than NafionTM due to the removal of –SO3H groups. The second part of this thesis deals with fluoropolymer-based anion-exchange membranes. A new class of coordinated metal/perfluoropolymer type composite membranes were synthesized and characterized for anion-exchange membrane fuel cells (AEMFCs). A membrane comprised of perfluoro(phenyl-2,2’:6’,2”-terpyridine) polymer, ZrO(ClO4)2 nanoclusters, and 2,2’:6’,2”-terpyridine displayed the highest conductivity of 23.1 mS/cm at 60 oC. The chemical stability test of composite membrane showed no conductivity loss after refluxing in 7 M KOH solution at 120 oC for 2,200 h. A H+ coordinated cage-shape molecule with a benzyl group (Bn-proton cage) was designed and synthesized as a base-stable anion-exchange group. By employing the free radical-based reaction, Bn-proton cage was grafted to a fluoropolymer to yield a stable anion-conductive membrane under alkaline conditions. The third part of this thesis is our design, synthesis and test of ionic liquids for reversible SO2 absorption. Novel di-cationic ionic liquids (DILs) were designed and synthesized for SO2 absorption. DILs were found to have better SO2 absorption capabilities than mono-cationic ionic liquids (MILs). A chloride-based DIL comprised of two N-methylimidazolium cations and a PEG9 (HO-(CH2CH2O)9-H) chain could reversibly uptake 3.710 mole SO2 per mole DIL under ambient conditions. The anion, temperature and water impact on SO2 absorption in DILs was investigated. Although replacing chloride with triflate or tosylate groups led to a reduced SO2 absorption for the DILs, a high selectivity against CO2 was observed in CO2 absorption test.

Poli(p-fenileno de tereftalamida) (PPTA), usualmente chamado de aramida, é uma fibra polimérica de baixa densidade que possui alta rigidez e resistência à tração, assim como excelente estabilidade térmica e química. Essa fibra é utilizada como reforço em materiais compósitos utilizados nas indústrias aeroespacial e automobilística, em artefatos de proteção balística e de proteção ao corte. No entanto, sua aplicação como reforço em materiais compósitos está limitada por sua baixa afinidade interfacial com matrizes poliméricas, devido a sua superfície lisa e relativamente inerte. Para superar esta desvantagem, diversos tratamentos foram desenvolvidos para modificar a superfície da aramida. Contudo, realizar essa modificação sem diminuir a resistência mecânica da fibra é um grande desafio, assim como desenvolver um método industrialmente viável. Líquidos iônicos (LI) apresentam-se como uma alternativa promissora para a compatibilização da aramida com matrizes poliméricas, devido à possibilidade de ajuste de suas propriedades com a escolha de ânions e cátions específicos. Dessa forma, o objetivo deste estudo é investigar a influência de diferentes LI nas propriedades adesivas entre Kevlar e uma resina epoxídica. Para tanto, as fibras foram submetidas a soluções de etanol e LI imidazólicos (cloreto de 1-n-butil-3-metilimidazólio, cloreto de 1-carboximetil-3-metilimidazólio, metanossulfonato de 1-trietilenoglicol monometil éter-3-metilimidazólio e metanossulfonato de 1-n-butil-3-metilimidazólio) e analisadas por espectroscopia do infravermelho, análise termogravimétrica e microscopia eletrônica de varredura. A resistência mecânica das fibras foi investigada por teste de tração e a interface foi caracterizada em termos de molhabilidade e adesão pelos testes de ângulo de contato e pull-out. Os resultados mostraram um aumento na molhabilidade e na adesão nas fibras tratadas com cloreto de 1- n-butil-3-metilimidazólico, metanossulfonato de 1-trietilenoglicol monometil éter-3- metilimidazólio e metanossulfonato de 1-n-butil-3-metilimidazólio. Dois compósitos laminados foram fabricados com os tecidos comercial e tratado com metanossulfonato de 1- trietilenoglicol monometil éter-3-metilimidazólio. Suas propriedades mecânicas foram aferidas por ensaios de tração e short beam. O compósito feito com o tecido tratado apresentou maior resistência mecânica, módulo e tensão de cisalhamento interlaminar. / Poly(p-phenylene terephthalamide) (PPTA), known as aramid, is a low density polymeric fiber that has high rigidity and exceptional tensile strength, as well as excellent thermal and chemical stability. It is used as reinforcement in composite materials in the aerospace and automobile industry and in ballistic and stab-resistant articles. However, its inferior interfacial affinity towards polymeric matrices due to its smooth surface hampers its use in composite materials, preventing full achievement of its potential as reinforcement. To overcome this drawback, various treatments have been applied to modify the aramid surface. Nevertheless it is a great challenge to introduce this modification without diminishing the fiber mechanical properties and to develop an industrially feasible process. Ionic liquids (IL) might be an alternative as compatibilizer in polymeric matrices reinforced with aramid fibers because of their unique set of physical-chemical properties that can be finely tuned by their chemical structures. Hence, the objective of this study is to investigate the influence of different IL on the adhesive properties between Kevlar and epoxy resin. Kevlar fibers were submitted to solutions of ethanol and imidazolium IL (1-n-butyl-3-methylimidazolium chloride, 1- carboxymethyl-3-methylimidazolium chloride, 1-n-hexadecyl-3-methylimidazolium chloride, 1- triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate and 1-n-butyl-3- methylimidazolium methanesulfonate) and then analyzed by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The mechanical strength of the fibers was analyzed by tensile strength tests and the interface was characterized by contact angle measurements and pull-out tests. There was an increase in wettability and adhesion of the fibers treated with 1-n-butyl-3-methylimidazolium chloride, 1-triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate and 1-n-butyl-3- methylimidazolium methanesulfonate. Two laminated composites were manufactured with commercial and 1-triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate treated fabrics and their mechanical properties were measured with tensile strength and short beam test. The composite made with treated fabrics presented higher mechanical resistance, modulus and interfacial shear strength.