Ce travail porte sur l’étude électrochimique de l’interface formée par une électrode d’or plongée dans le liquide ionique 1-butyl-3-methylimidazolium dicyanamide ou [BMIm][DCA]. Ce liquide ionique a été sélectionné car outre sa conductivité intrinsèque, il permet de solubiliser aisément des sels de métaux de transition à température ambiante. Les liquides ioniques sont, par définition, des sels liquides en dessous de 100 °C et la plupart d’entre eux sont liquides à température ambiante. Etant donné que les liquides ioniques sont constitués majoritairement d’ions, la description de la double couche électrique telle que décrite dans les électrolytes traditionnels doit être reconsidérée.<p>Deux grandes thématiques fondamentales sont abordées dans ce travail :le comportement de la double couche électrique à l’interface liquide ionique / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

La synthèse de nanogels par voie directe est étudiée par la copolymérisationradicalaire réticulante contrôlée par le cobalt (CMRCcP) d’un monomère monovinylique et d’unréticulant divinylique. La synthèse de nanogels globulaires a été réalisée en utilisant unsystème de co-monomères soit neutres (acétate de vinyle et adiapte de divinyle) soit liquidesioniques. Le contrôle de la polymérisation est vérifié dans tous les cas, les liaisons C-Cosituées aux extrémités des chaînes polymères ont été réactivées, afin de former des nanogelsde « seconde-génération ». Dans le cas de monomères liquides ioniques, différents contreanionsont été utilisés afin de jouer sur l’hydrophilie des co-monomères : la CMRCcP dubromure de N-vinyl-3-ethyl imidazolium (VEtImBr) et du bromure de 1,13-divinyl-3-decyldiimidazolium (DVImBr) a été réalisée dans l’eau, à 30 °C, pour former des nanogelspoly(VEtImbr-co-DVImBr) hydrophiles. Les propriétés antibactériennes de ces nanogels ontété étudiées.Les pendants hydrophobes de ces nanogels à base de PILs ont été synthétisés via laCMRCcP directe, dans l’acétate d’éthyle, de co-monomères contenant des contre-anionsbis(trifluromethanesulfonyl)imide (NTf2-). La capacité à former des surfaces poreusesordonnées de ces nanogels hydrophobes poly(VEtImNTf2-co-DVImNTf2) a été examinée, ainsique leur conductivité ioniques en films minces.Des copolymérisations ‘mixtes’ ont également été étudiées, dans l’optique de formerdifférentes architectures nanogels en utilisant des co-monomères ayant des réactivités trèsdifférentes. / The syntheses of globular nanogels were first investigated under mild conditions,using a mono- and a divinyl co-monomer with similar reactivities. CMRCcP was implementedon either neutral (vinyl acetate (VAc) and divinyl adipate (DVA)) co-monomers, or ionic liquidco-monomers. Control over each polymerization was ascertained, and dormant cobaltcarbonchain-ends could be re-activated to form “second-generation” nanogels. CMRCcP ofN-vinyl-3-ethyl imidazolium bromide (VEtImBr) and 1,13-divinyl-3-decyl diimidazoliumbromide (DVImBr) was achieved in water at 30 °C, leading to hydrophilic poly(VEtImBr-co-DVImBr) nanogels. The antibacterial activity of these cross-linked structures wasinvestigated. The hydrophobic pendants of these PIL-based nanogels were synthesized viadirect CMRCcP in ethyl acetate, using bis(trifluromethanesulfonyl)imide (NTf2-) counteranions. An array of these poly(VEtImNTf2-co-DVImNTf2) nanogels was then investigated aspossible coatings for porous patterned surfaces, and their ionic conductivity assessed.Different cross-linked architecture were approached, using a mono- and a divinyl comonomersof completely different reactivities.

Polymer magnetic composite (PMC) nanoparticles have gained a large attention due to their potential use in several biomedical applications from biomedical to engineering field. Among the different heterogeneous polymerization techniques that are generally used to prepare hybrid polymer particles, miniemulsion polymerization is proved to be an efficient one. The occurrence of preferential droplet nucleation in case of miniemulsion polymerization results in a 1:1 copy of monomer droplets to the polymer particles and such a mechanistic pathway offers a suitable environment for the preparation of hybrid polymer nanoparticles in the range between 50 to 500 nm. The surfactant in miniemulsoin plays a significant role to stabilize the droplets/particles and also in the encapsulation of nanoparticles. In the present study, a new class of surfactant, called amphiphilic ionic liquid, has been employed in the field of miniemulsion. The amphiphilic ionic liquid has amazing ability to impart surface tunable characteristics to the polymer particles when present on the surface of the particles. Thus the aim of the present work is to synthesize polymer magnetic composite nanoparticles with good colloidal stability, high content of magnetic nanoparticles as well as the chance for further surface functionality. Such magnetic nanoparticles may find applications in various fields. At first, the aim of the work was to establish a suitable recipe with ionic liquid as surfactant for the execution of miniemulsion polymerization. Monodisperse polystyrene nanoparticles were possible to be synthesized reproducibly. The established recipe was utilized to carry out the synthesis of PMC nanoparticles. Iron oxide (Fe3O4) was taken as magnetic nanoparticles (MNP) and it was hydrophobized with oleic acid to disperse in styrene. The concentration of feed MNP was varied to observe its influence on the characteristics of PMC nanoparticles. Stable dispersion of magnetic polystyrene particles was possible to be synthesized up to 8 wt% feed MNP. But feeding 12 wt% MNP resulted in the development of large amount of coagulum associated with instability in the dispersion. TGA investigation confirmed a significantly lower MNP content (8.2 wt%) of the composite compared to the feed amount. TEM investigation showed inhomogeneous distribution of MNP among polystyrene particles and agglomeration of MNP was observed on the surface of polystyrene particles. Considering the inability of the single step miniemulsion polymerization for the preparation of high MNP content polymer particles, it was aimed to find a new strategy which can produce such material. Inspired from the affinity of carboxylic acid group towards the surface of MNP, it was aimed to synthesize carboxyl functionalized polystyrene which was expected to improve the interaction between polymer and magnetic nanoparticles. For this purpose, RAFT mediated miniemulsion polymerization was performed in presence of a carboxyl functionalized chain transfer agent (CTA). The colloidal stability was much better compared to the previous case of non-RAFT experiments. From a feed MNP of 8 wt%, a high final MNP content up to ~27 wt% could be achieved and all the dispersions were highly stable. The higher MNP content in the final composites compared to the feed ratio was a result of the low monomer conversion and could be adjusted by a proper tuning of AIBN to CTA mole ratio. Another significant influence of the carboxyl functionalized CTA was observed on the morphology of the composite nanoparticles. The MNP were distributed homogeneously among the PS particles. Regarding the dispersion of MNP in the individual polystyrene particles, it was observed that higher amount of CTA resulted in a homogeneous dispersion of MNP whereas higher amount of initiator ended up producing asymmetric Janus like morphology. Apart from that, due to the involvement of CTA in the polymerization, much lower molecular weight of the polystyrene chains was developed compared to the free radical process and the molecular weight distribution of PS in the composite nanoparticles became much narrower through the RAFT polymerization. Thus a relatively good control over the polymerization process was achieved through RAFT polymerization which was confirmed by a nearly linear increase of molecular weight (Mn) with time of polymerization and thus, monomer conversion. In the recipe of miniemulsion, costabilizer plays an important role to retard monomer diffusion from smaller to larger droplets. Hexadecane, being the most frequently used costabilizer for miniemulsion, has been employed in this study so far. But its volatile nature restricts its utilization in several applications. For the replacement of hexadecane, a carboxyl functionalized polystyrene is employed as a costabilizer as well as a macro CTA in miniemulsoin polymerization of styrene. For this purpose, low molecular weight carboxyl bi-functionalized polystyrene (9000 g/mole) was synthesized by thermal bulk RAFT polymerization. The carboxylated polystyrene worked successfully as a costabilizer in miniemulsion and molecular weight investigation confirmed the integration of the carboxyl functionalized macro CTA into the developing polystyrene chain via RAFT polymerization. This strategy was employed successfully to synthesize stable dispersion of PMC nanoparticles with a reasonable content of MNP in the system. A homogeneous morphology was observed regarding the distribution of MNP among the polystyrene particles. The strategy of using macro CTA as costabilizer can be utilized to synthesize various functional copolymers with control architecture without any added monomer and CTA in the system. Moreover, presence of functionality within the monomer droplets can be effective to encapsulate several nanomaterials using miniemulsion polymerization.

L'idée à la base de ce projet est de mettre à profit le confinement nanométrique unidimensionnel pour décupler la conduction ionique des électrolytes et donc la puissance des accumulateurs au lithium. Nous avons concentré nos efforts sur une classe particulière d'électrolytes qui, en raison de leurs stabilités physique et électrochimique, ont été identifiés comme prometteurs: les Liquides Ioniques (LI). Nous avons confiné les LI dans deux systèmes poreux présentant une topologie commune (pores cylindriques macroscopiquement orientés) mais aux propriétés physico-chimiques complémentaires: i) des alumines poreuses (AAO, interface hydrophile, diamètre des pores de 25 à 160 nm) et ii) des membranes de NanoTubes de Carbone (NTC, interface hydrophobe, diamètre des pores 4 nm).Nous avons développé un modèle microscopique multi-échelle original, prenant en compte la dynamique complexe des cations des LI: combinaison i) de la dynamique de réorientation rapide des chaînes latérales alkyle, ii) de la diffusion de la molécule au sein des agrégats nanométriques spontanément formés par les LI, puis iii) de la diffusion entre ces agrégats. Ce modèle reproduit de façon remarquablement robuste les données de diffusion quasi-élastique de neutrons sur une gamme étendue de vecteurs de diffusion (0,1 à 2,5 Å-1) et de temps (10-1 à 2.103 ps). A cette échelle locale, nous ne détectons pas d'influence du confinement sur la dynamique du LI confiné au sein des AAO et des CNT. Nous montrons cependant qu'à l'échelle microscopique (PFG-NMR) et macroscopique (spectroscopie d'impédance) le confinement des LI au sein des NTC permet d'obtenir un gain de conductivité d'un facteur 3. Un brevet est déposé. / The idea behind this project is to exploit the 1D nanometric confinement in order to increase the electrolytes ionic conductivity and, thus, the power of the lithium accumulators. We have focus on a specific class of electrolytes, which, owing to their physical and electrochemical stabilities, have been identified as very promising: the Ionic Liquids (ILs). We have confined the ILs in porous systems having a common topology (cylindrical pores macroscopically oriented), but with complementary physico-chemical properties: i) the porous alumina (AAO, hydrophilic interface, pores diameter between 25 and 160 nm) and ii) Carbon NanoTubes based membranes (CNT, hydrophobic interface, pores diameter of 4 nm).We have developed an original microscopic multiscale model, taking into account the complex dynamics of ILs cations: combination of i) fast reorientation dynamics of side alkyl-chains, ii) molecule diffusion within nanometric aggregates spontaneously formed in the ILs and iii) diffusion between the aggregates. This model reproduces in a very robust way the quasi-elastic neutrons scattering data on an extent interval of wave vector (0.1 à 2.5 Å-1) and time (10-1 à 2.103 ps). At this local scale, we do not observe any influence due to the confinement on the dynamics of the ILs confined in the AAO and CNTs. We show however that at microscopic (PFG-NMR) and macroscopic (impedance spectroscopy) scale the ILs confinement within the NTCs allows to obtain a conductivity gain of factor 3. A patent is filed.

Ces travaux portent sur l'élaboration de catalyseurs hétérogènes en milieu liquide ionique (LI). Ces sels liquides à température ambiante permettent d'ajuster les propriétés du solvant suivant la composition chimique du LI mis en jeu (sels d'imidazolium ou Deep Eutectic Solvent à base de chlorure de choline et urée). Ce type de solvant a permis la synthèse et le dépôt de nanoparticules (NPs) d'Au et Au-Pd sur TiO2. Le type de LI utilisé influence la stabilité des NPs en solution, la force de l'interaction métal/support et la nanostructuration des particules bimétalliques. Les performances catalytiques en hydrogénation sélective du butadiène ont montré une amélioration de l'activité des catalyseurs monométalliques à base d'Au en présence de Pd, une promotion de l'activité des catalyseurs (mono-et bimétalliques) par des espèces phosphorées résiduelles issues du LI et une inhibition de l'activité par des espèces soufrées. Des supports TiO2 ont également été préparés en milieu DES. L'utilisation de ce LI et d'un précurseur de Ti spécifique a permis de contrôler la texture et la structure du polymorphe obtenu (anatase, rutile ou mélange anatase-rutile). L'influence de la nature du support a été étudiée en oxydation du CO après dépôt d'Au par dépôt-précipitation à l'urée. Les catalyseurs Au/TiO2 les plus actifs ont été obtenus pour des mélanges anatase-rutile, la proximité entre phases anatase et rutile menant à un optimum de réactivité et de stabilité. / This work deals with the elaboration of heterogeneous catalysts in ionic liquids (ILs). These salts, liquid at room temperature, were chosen because they permit to adjust the solvent properties depending on their chemical composition (imidazolium salts or Deep Eutectic Solvent based on choline chloride and urea). These solvents allowed the synthesis and deposition of Au and Au-Pd nanoparticles (NPs) on TiO2. The IL nature controls the NPs stability in solution, the strength of the metal/support interaction and the nanostructuration of bimetallic particles. The catalysts performances, evaluated by selective hydrogenation, showed an increase in activity of the Au monometallic catalysts after addition of Pd, a promotion of the catalysts activity due to the presence of P residues from the ILs and an inhibition of the activity caused by S species. TiO2 supports were also prepared in DES. The use of this IL, in addition to a specific Ti precursor, led to a textural and structural control of the obtained polymorphs (anatase, rutile or anatase-rutile mixture). The influence of the support type was studied in CO oxidation after Au deposition by urea deposition-precipitation. The most active Au/TiO2 catalysts were obtained with anatase-rutile mixtures, the vicinity between anatase and rutile phases leading to an optimum activity and stability.This work deals with the elaboration of heterogeneous catalysts in ionic liquids (ILs). These salts, liquid at room temperature, were chosen because they permit to adjust the solvent properties depending on their chemical composition (imidazolium salts or Deep Eutectic Solvent based on choline chloride and urea). These solvents allowed the synthesis and deposition of Au and Au-Pd nanoparticles (NPs) on TiO2. The IL nature controls the NPs stability in solution, the strength of the metal/support interaction and the nanostructuration of bimetallic particles. The catalysts performances, evaluated by selective hydrogenation, showed an increase in activity of the Au monometallic catalysts after addition of Pd, a promotion of the catalysts activity due to the presence of P residues from the ILs and an inhibition of the activity caused by S species. TiO2 supports were also prepared in DES. The use of this IL, in addition to a specific Ti precursor, led to a textural and structural control of the obtained polymorphs (anatase, rutile or anatase-rutile mixture). The influence of the support type was studied in CO oxidation after Au deposition by urea deposition-precipitation. The most active Au/TiO2 catalysts were obtained with anatase-rutile mixtures, the vicinity between anatase and rutile phases leading to an optimum activity and stability.

Atualmente, pelo menos para fins de engenharia, os modelos preditivos de maior sucesso para coeficientes de atividade são os baseados em grupos funcionais, tais como UNIFAC e suas variantes. Enquanto esses modelos requerem grandes quantidades de dados experimentais, os baseados em COSMO-RS (COnductor-like Screening MOdel - for Real Solvents) requerem a calibração de um pequeno conjunto de parâmetros universais. No entanto, a precisão requerida por tarefas de engenharia, tais como a otimização de sistemas de separação, é maior do que a obtida por esta última categoria de modelos. Assim, um novo modelo é proposto neste trabalho, aqui chamado de F-SAC (Functional-Segment Activity Coefficient). Este novo modelo também é baseado no conceito de grupos funcionais, mas a energia de interação entre os grupos vem da teoria COSMO-RS. No presente trabalho, foram consideradas apenas misturas em que não há formação de ligação de hidrogênio ou quando esta pôde ser assumida negligenciável. Assim, foram necessários apenas três parâmetros para descrever cada grupo funcional. A princípio, uma vez ajustados os parâmetros de cada grupo, estes funcionariam para descrever a interação para qualquer par de grupos. Esta é a principal vantagem do modelo proposto. O número de parâmetros do modelo cresce proporcionalmente ao número de grupos funcionais, enquanto que no UNIFAC o número de parâmetros de interação cresce proporcionalmente ao quadrado do número de grupos. Para o banco de dados experimentais de coeficientes de atividade em diluição infinita considerado, a correlação do F-SAC apresentou um erro médio absoluto de 0,07 unidades de ln, enquanto que os modelos UNIFAC (Do) e COSMO-SAC apresentaram, respectivamente, erros de 0,12 e 0,21. O F-SAC foi também avaliado para mais de 1000 misturas binárias de um soluto dissolvido em líquido iônico com dados disponíveis na literatura. O modelo apresentou uma boa correlação aos dados experimentais, com erro médio absoluto de 0,17 unidades de ln, similar ao apresentado pelas misturas orgânicas. O poder de predição do novo modelo foi avaliado utilizando dados de equilíbrio líquido-vapor não considerados no procedimento de ajuste do modelo. Uma ótima concordância com os dados experimentais foi possível em toda a faixa de composição, bem como na predição de azeótropos. Esses resultados demonstram o potencial do modelo proposto. / At present, at least for engineering purposes, the most successful predictive models for activity coefficients are those based on functional groups, such as UNIFAC and its variants. While these models require large amounts of experimental data, the ones based on COSMO-RS require the calibration of a small set of universal parameters. However, the resolution required by engineering tasks, such as the optimization of separation systems, is higher than that obtained by COSMO-RS models. Thus, in this work a novel Functional-Segment Activity Coefficient (F-SAC) model is proposed. This new model is also based on the concept of functional groups, but the interaction energy between groups comes from the COSMO-RS theory. In this study, we considered only mixtures where there is no formation of hydrogen bonds or when they could be assumed negligible. Then, only three parameters were required to describe each functional group. In principle, once the parameters for each functional group are properly calibrated, they should work to describe the interactions with any other group. This is the main advantage of the proposed model, the number of model parameters grows linearly with the number of functional groups, whereas in UNIFAC the number of interaction parameters exhibit quadratic growth with respect to the number of groups. For the experimental database of infinite dilution activity coefficients considered, the correlation of F-SAC have shown a mean absolute error of 0.07 ln-unit. The UNIFAC (Do) and COSMO-SAC models presented errors of 0.12 and 0.21, respectively. F-SAC was also evaluated for more than 1000 binary mixtures of solute in ionic liquid with data available in the literature. Again, the model have shown good correlation to the experimental data, with mean absolute error of 0.17 ln-unit, similar to the performance with the organic mixtures. The predictive strength of the model was assessed by using vaporliquid equilibrium data not considered in the model fitting process. Very good agreement with experimental data was possible over the entire composition range, as well as in the prediction of azeotropes. These results demonstrate the potential of the proposed method.

Orientadores: Maria Regina Wolf Maciel, Carlos Eduardo Vaz Rossell / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-26T10:10:41Z (GMT). No. of bitstreams: 1 Alves_Moises_D.pdf: 2341942 bytes, checksum: 15b4471c1a44c4b51fad94e70bd4ebc4 (MD5) Previous issue date: 2014 / Resumo: Neste trabalho, realizou-se o estudo da produção de etanol anidro por meio do processo de destilação extrativa, tomando por base uma usina sucroalcooleira que processa 15000 toneladas de cana por dia. Utilizou-se como ferramenta computacional o software Aspen Plus®, o qual possui recursos computacionais que permitem compatibilizar as simulações com processos reais. Nas simulações deste trabalho foram utilizados os solventes monoetilenoglicol e o líquido iônico cloreto de 1- metilimidazólio, assim como os modelos de estágios de equilíbrio e de não equilíbrio. Os resultados da análise de sensibilidade para utilização do solvente monoetilenoglicol na coluna de destilação extrativa, em alta temperatura, apresentou economia de até 0,04 kg de vapor/litro de etanol anidro e de 0,37 kg de vapor/litro de etanol anidro ao alimentar o etanol hidratado produzido em colunas de destilação diretamente em colunas extrativas, sem estocagem e sem necessidade de aquecimento deste etanol hidratado. As colunas de destilação extrativa e de recuperação, do processo de destilação extrativa, apresentaram eficiências globais de 71,68% e 64,25%, respectivamente, segundo a correlação de O¿Connell. Foi realizado o estudo do consumo energético em colunas que operavam com pressões de 1,0 atm, 0,7 atm, 0,5 atm e 0,3 atm produzindo etanol anidro com fração mássica de 0,997. Os resultados mostraram que as colunas que operam em pressões menores que a atmosférica apresentaram redução na razão de refluxo em mais de 4,5 vezes e redução no consumo de vapor de 39,62%. Ao comparar o consumo de vapor em sistema que utiliza coluna extrativa e de recuperação, com pressão de 1,0 atm ou com pressão de 0,3 atm, foi constatado que a redução na pressão de operação das colunas gerou um excedente de vapor de 1,845 MWh. Os resultados também mostraram que o consumo de energia de uma bomba de vácuo necessária para gerar baixa pressão em colunas extrativa e de recuperação é menor que 1,5% para os diferentes níveis de pressão. O estudo com o solvente líquido iônico cloreto de 1-metilimidazólio apresentou redução mássica de utilização do solvente igual a 41,16%, demonstrado por meio da razão S/F igual a 0,353 para o líquido iônico e de 0,60 para o monoetilenoglicol. O estudo com o cloreto de 1-metilimidazólio mostrou a redução do consumo de vapor no processo em 27,3%, em relação ao solvente monoetilenoglicol, somadas as colunas extrativa e de recuperação. Foi realizada a simulação do modelo de não equilíbrio, levando em consideração parâmetros específicos das bandejas. Os resultados mostraram que a energia consumida no modelo de estágios de não equilíbrio apresentou aumento de 92,5% em relação ao modelo estágio de equilíbrio / Abstract: In this work, the study of the production of anhydrous ethanol by means of the extractive distillation process was carried out, based on a sugar and alcohol plant that processes 15,000 tons of sugar cane per day. The software Aspen Plus® was used as a computational tool, which has computational resources that adapt the simulations with real processes. In this study¿s simulations monoethylene glycol and the ionic liquid 1- methylimidazolium were used as solvents, as well as models of equilibrium and nonequilibrium. The results of the sensitivity analyses when using monoethylene glycol as the solvent, in the extractive distillation column, at high temperature, showed savings of up to 0.04 kg of steam / liter of anhydrous ethanol, and 0.37 kg of steam / liter of anhydrous ethanol when feeding the hydrous ethanol produced in the distillation columns directly into the extractive columns without the need for storage and of heating that hydrous ethanol. The extractive distillation and recovery columns, of the extractive distillation process, have shown overall efficiencies of 71.68% and 64.25%, respectively, according to the O'Connell correlation. We have conducted the study of energy consumption in columns operating at pressures of 1.0 atm, 0.7 atm, 0.5 atm and 0.3 atm producing anhydrous ethanol with a mass fraction of 0.997. The results have shown that the columns operating at pressures lesser than the atmospheric one decreased the reflux ratio more than 4.5 times, and the steam consumption by 39.62%. When comparing the steam consumption in the system using an extraction and recovery column, with a pressure of 1.0 atm or a pressure of 0.3 atm, it was found that the reduction in the column operating pressure generated 1.845 MWh of steam surplus. The results have also shown that the power consumption of a vacuum pump needed to generate a low-pressure in the extraction and recovery columns is lesser than 1.5% for different levels of pressure. The study of the ionic liquid solvent 1-methylimidazolium chloride had a mass reduction of solvent usage equal to 41.16%, shown by the S / F ratio equal to 0.353 for the ionic liquid and 0.60 for MEG. The study with 1-methylimidazolium chloride revealed that the steam consumption reduction in the process is 27.3%, compared to the monoethylene glycol solvent, combining the extraction and recovery columns. The simulation model of the non-equilibrium has been carried out taking into account specific parameters of the trays. The results showed that the power consumption in the nonequilibrium stage model displayed an increase of 92.5% compared to the equilibrium stage model. / Doutorado / Engenharia de Processos / Doutor em Engenharia Química

Orientador: Ana Flavia Nogueira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-14T14:27:05Z (GMT). No. of bitstreams: 1 Freitas_FlavioSantos_M.pdf: 1335737 bytes, checksum: 43bb80b2fab0adc9d9092583a0f45e94 (MD5) Previous issue date: 2009 / Resumo: Neste trabalho foram investigados eletrólitos poliméricos baseados em poli(óxido de etileno-co-2-(2-metoxietoxi) etilglicidiléter) - P(EO-EM) com adição do oligômero dibenzoato de etileno-glicol (DIB)/LiI/I2 e poli(óxido de etileno-co-óxido de propileno) - P(EO-PO), com adição do líquido iônico iodeto de 1-metil-3- propilimidazólio (MPII)/I2 (com e sem a presença de LiI), visando a aplicação em células solares de TiO2/corante. Os eletrólitos foram caracterizados por Calorimetria Exploratória Diferencial (DSC), Espectroscopia de Infravermelho com Transformada de Fourier (FTIR), Ressonância Magnética Nuclear de Hidrogênio (H RMN) e Espectroscopia de Impedância Eletroquímica (EIE). Para o sistema P(EO-EM)/DIB, os estudos realizados por DSC e FTIR mostraram alta homogeneidade entre os componentes, com evidências de coordenação de sal no copolímero e no oligômero. Nas medidas de condutividade iônica, verificou-se saturação em ~10 S cm a partir de 10 % de LiI para todas as proporções de PEO-EM/DIB. Como conseqüência, a aplicação de eletrólitos com 20 % de LiI apresentou resultados bem similares, independente da proporção de DIB no sistema, indicando que os processos cinéticos relacionados ao transporte de carga são diferentes dos eletrólitos géis reportados na literatura, não sendo verificada mudança no potencial de circuito aberto (VOC) dos dispositivos. Para o sistema P(EO-PO)/MPII, as análises por DSC, FTIR e H RMN evidenciaram interações entre o oxigênio do copolímero e o hidrogênio do cátion imidazólio, possibilitando aumento na difusão do par I /I3 (estimado em 1,9x 10 cm s para o eletrólito com 70 % de MPII). A maior condutividade iônica foi obtida para o eletrólito com 70 % de MPII (2,4 x 10 S cm), possibilitando a montagem de células solares com eficiência de 5,66 %. Para todos os dispositivos, a presença de íons I3 promoveu aumento nas reações de recombinação, observando-se valores menores para o VOC com o aumento da concentração de MPII nos eletrólitos. Após a adição de LiI, não foram observadas melhores eficiências em comparação aos dispositivos montados sem a adição do sal. Esses resultados indicam que eletrólitos poliméricos baseados na combinação de polímero e líquido iônico consistem em sistemas promissores para aplicação em células solares. / Abstract: New polymer electrolytes based on poly(ethylene oxide-co-2-(2- methoxyethoxy)ethylglycidylether) - P(EO-EM) with addition of the oligomer ethyleneglycol dibenzoate (DIB)/LiI/I2, and poly(ethylene oxide-co-propylene oxide) - P(EO-PO) with addition of the ionic liquid 1-methyl-3-propylimidazolium (MPII)/I2 (with and without LiI) were investigated in this work aiming at the application in dye-sensitized solar cells. The electrolytes were characterized using Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Ressonance (H NMR) and Complex Electrochemical Impedance Spectroscopy (EIS). For the P(EO-EM)/DIB system, the DSC and FTIR measurements revealed a homogeneous mixture, with evidence of coordination of the salt with both the copolymer and the oligomer. The ionic conductivity measurements presented saturation in ~10 S cm for samples containing at least 10 % of LiI, for all P(EO-EM)/DIB concentration ratios. As consequence, the solar cells assembled with electrolytes containing 20 % of LiI presented similar performance, regardless of the DIB concentration, indicating that the kinetic processes related to the charge transport in these systems are different from those usually observed for gel electrolytes (which cause changes in the open circuit potential, VOC, of the devices). For the P(EO-PO)/MPII system, the DSC, FTIR and HNMR measurements revealed the presence of interactions between the oxygen atoms in the copolymer and the hydrogen atoms from the imidazolium cation, which increased the diffusion of the I/I3 redox couple (estimated to be 1,0 x 10 cm s for the electrolyte containing 70 % if MPII). The highest ionic conductivity was observed for the electrolyte containing 70 % of MPII (2,4 x 10 S cm), leading to the assembly of solar cells with 5,66 % of efficiency. In all the devices assembled, the presence of I3 ions leads to an increase of the recombination reactions, thus reducing the VOC values. This effect is more pronounced for higher concentrations of MPII in the electrolyte. After addition of LiI to these systems, no improvements in the device efficiency were observed. These results show that polymer electrolytes based on the mixture of polymer and ionic liquids are very promissing systems for application in solar cells. / Mestrado / Quimica Inorganica / Mestre em Química

The rapidly expanding of the global population in the 21st-century forces people facing two serious problems: water scarcity and energy shortage. Enormous continuous studies focus on providing enough fresh water and energy in a sustainable way. This thesis aims at exploring novel membrane processes based on thermally responsive ionic liquids with the upper critical solution temperature (UCST ILs) for water desalination and energy conversion from low-grade heat energy to electricity. A UCST IL protonated betaine bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) was first experimentally studied as a novel draw solute in a thermal forward osmosis (FO). A 3.2 M [Hbet][Tf2N] solution can be obtained via spontaneous phase separation from an IL and water mixture at room temperature. By heating and maintaining the temperature above 56°C, this solution can draw water from high-salinity solution up to 3.0 M, 5 times salty as the sea water. The IL draw solution can be easily regenerated by phase separation. Conducting the FO process at higher temperatures can also increase the water flux. According to the different choices of the freshwater polishing step, the electric energy consumption in this novel process was estimated as 26.3% to 64.2% of conventional one-step sea water reverse osmosis. Two UCST ILs with better performance, [Hbet][Tf2N] and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]), were selected as the agents in a novel closed-loop thermally responsive IL osmotic heat engine (TRIL-OHE) to convert low-grade thermal energy to electricity. The specific energies of the [Hbet][Tf2N] system and the [Choline][Tf2N] system are 2500 kJ/t and 3700 kJ/t, which are 2.7 and 4.0 times of the seawater and river water system, respectively. The maximum power density measured from a commercial FO membrane is 1.5 W/m2 for the [Hbet][Tf2N] system and 2.3 W/m2 for the [Choline][Tf2N] system, leaving a big room to improve if highly permeable membranes are used. Another notable advantage of the TRIL-OHE is the heat released from the cooling stage can be largely recovered. A rigorous energy balance showed with a 70% heat recovery, the energy efficiency could be increased from around 20% to 70% of the Carnot efficiency in both UCST ILs systems.

全文ファイル差し替え（2021.07.28） / 京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第22132号 / エネ博第400号 / 新制||エネ||77(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 萩原 理加, 教授 佐川 尚, 教授 野平 俊之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM