Liquid chromatography is an essential technique in manufacturing biopharmaceuticals where it is used on all scales from analytical applications in R&amp;D to full-scale production. In chromatography the target molecule, typically a protein, is separated and purified from other components and contaminants. Separation is based on different affinities of different molecules for the chromatographic medium and the physical and chemical properties of the latter determine the outcome. Controlling and designing those properties demand efficient analytical techniques. In this thesis the approach was to develop characterization methods based on nuclear magnetic resonance (NMR) spectroscopy for the assessment of various important physico-chemical properties. The rationale behind this strategy was that the versatility of NMR – with its chemical and isotopic specificity, high dynamic range, and direct proportionality between the integral intensity of the NMR signal and the concentration of spin-bearing atomic nuclei (e.g., 1H, 13C, 31P and 15N) – often renders it a very good choice for both qualitative and quantitative evaluations. These characteristics of NMR enabled us to develop two quantification methods for chromatography-media ligands, the functional groups that provide the specific interactions for the molecules being separated. Furthermore, a new method for measuring the distribution of macromolecules between the porous chromatographic beads and the surrounding liquid was established. The method, which we have named size-exclusion quantification (SEQ) NMR, utilizes the fact that it is possible to assess molecular size distribution from corresponding distribution of the molecular self-diffusion coefficient where the latter is accessible by NMR. SEQ-NMR results can also be interpreted in terms of pore-size distribution within suitable models. Finally, we studied self-diffusion of small molecules inside the pores of chromatographic beads. The results provided new insights into what affects the mass transport in such systems. The methods presented in this thesis are accurate, precise, and in many aspects better than conventional ones in terms of speed, sample consumption, and potential for automation. They are thus important tools that can assist a better understanding of the structure and function of chromatography media. In the long run, the results in this project may lead, via better chromatographic products, to better drugs and improved health. / Vätskekromatografi är en viktig teknik för tillverkning av biologiska läkemedel och används för alltifrån småskaliga analytiska applikationer till fullskalig produktion. I kromatografi separeras och renas målmolekylen (oftast ett protein), från andra komponenter och föroreningar genom att utnyttja molekylernas olika affinitet för det kromatografiska mediumet, vars fysikaliska och kemiska egenskaper har stor betydelse för hur separationen fungerar. För att kunna kontrollera och designa dessa egenskaper krävs effektiva analysmetoder. Strategin i den här avhandlingen var att utveckla metoder baserade på kärnmagnetisk resonans (NMR) spektroskopi för att karaktärisera flera viktiga fysikalisk-kemiska egenskaper. Anledningen till denna strategi är att mångsidigheten hos NMR – med dess kemiska och isotopiska specificitet, stora dynamiska omfång och direkta proportionalitet mellan NMR-signalens integralintensitet och koncentrationen av spinnbärande atomkärnor (t.ex. 1H, 13C, 31P och 15N) - ofta gör den till det bästa valet för både kvalitativa och kvantitativa tillämpningar. Dessa egenskaper hos NMR gjorde att vi kunde utveckla två kvantifieringsmetoder för kromatografimedia-ligander, dvs de funktionella grupperna som ger de specifika interaktioner som gör att molekylerna kan separeras. Dessutom har en ny metod för att mäta fördelningen av makromolekyler mellan de porösa kromatografiska pärlorna och den omgivande vätskan tagits fram. Metoden, som vi har valt att kalla size-exclusion quantification (SEQ) NMR, utnyttjar det faktum att det är möjligt att mäta molekylstorleksfördelningen genom att mäta motsvarande fördelning av självdiffusionskoefficienter, där den sistnämnda kan bestämmas med NMR. Resultaten från SEQ-NMR kan tolkas i termer av porstorleksfördelningar genom att använda lämpliga modeller. Slutligen studerade vi självdiffusion av små molekyler inuti porerna i kromatografiska pärlor. Resultaten gav nya insikter om vad som påverkar masstransporten i sådana system. De metoder som presenteras i denna avhandling är noggranna, precisa och på många sätt bättre än konventionella metoder när det gäller hastighet, låg provförbrukning och automatiseringspotential. De nya metoderna är därför viktiga verktyg som kan hjälpa till att ge en bättre förståelse av struktur och funktion hos kromatografimedia. I det långa loppet kan resultat från det här projektet kunna bidra till effektivare kromatografiska produkter, vilket i slutändan kan leda till bättre läkemedel och hälsa. / <p>QC 20170403</p>

Aerogel materials have had limited utility due to their fragility, geometrical limitations, fabrication costs and protracted fabrication times. The objective of this project was to eliminate these limitations. Native, cross-linked and hybrid aerogel monoliths have been fabricated using a newly developed one-pot method without the need for solvent exchange. The key to this technique is the use of an ethanol–water azeotrope mixture, which contains 4.4% water by volume, as both a gelation and supercritical drying solvent. The small water content allows for drying at temperatures close to the supercritical temperature of the dry solvent, where reactions such as silica dissolution and polymer degradation are negligible. This improvement on conventional fabrication processes is of particular importance since it decreases the total duration of aerogel fabrication from five days to one day. Cross-linked silica aerogel monoliths were fabricated using one-pot hydrolysis-condensation wet chemistry methods as well as a rapid photogelation method. Both native silica and cross-linked aerogel components were made with a minimum dimension of up to 3.6 cm and in customizable shapes. Fabrication of homogeneous aerogels using these methods required a maximum of one day, as demonstrated in this work. Finally, LEDs and Laser irradiation were both used to selectively embed cross-linked aerogel into a larger native silica component to provide reinforcement and/or a surface which can be used for labeling or affixing the aerogel component to another surface.

This thesis is concerned with developing porous materials from tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy exchanges. The materials developed are also able to insulate against heat by suppressing the convection of heat and reduced conductivity of the fluid locked in the large proportion of close-cell pores. The acoustic absorption performance of a porous media is controlled by the number of open cells and pore size distribution. Therefore, this work also investigates the use of catalysts and surfactants to modify the pore structure and studies the influence of the various components in the chemical formulations used to produce these porous materials. An optimum type and amounts of catalyst are selected to obtain a high chemical conversion and a short expanding time for the bubble growth phase. The surfactant is used to reduce the surface tension and achieve a homogenous mixing between the solid particulates tyre shred residue, the water, the catalyst and the binder. It is found that all of the components significantly affect the resultant materials structure and its morphology. The results show that the catalyst has a particularly strong effect on the pore structure and the ensuing thermal and acoustical properties. In this research, the properties of the porous materials developed are characterized using standard experimental techniques and the acoustic and thermal insulation performance underpinned using theoretical models. The important observation from this research is that a new class of recycled materials with pore stratification has been developed. It is shown that the pore stratification can have a positive effect on the acoustic absorption in a broadband frequency range. The control of reaction time in the foaming process is a key function that leads to a gradual change in the pore size distribution, porosity, flow resistivity and tortuosity which vary as a function of sample depth. It is shown that the Pade approximation is a suitable model to study the acoustic behaviour of these materials. A good agreement between the measured data and the model was attained.

La complexité des mécanismes de transport en nanofiltration (NF) nécessite ledéveloppement d’outils de modélisation fiables permettant de comprendre et d’optimiser lesopérations de séparation en NF.La présente étude comprend deux volets. Le premier porte sur la rétention d’un soluténeutre – le poly(éthylène glycol) à 600 g mol-1 (PEG) – seul et en présence d’ions, par unemembrane organique de NF (polyamide). Les résultats obtenus montrent que la rétention dusoluté neutre chute en présence d’ions et ce, d’autant plus que la concentration du sel estélevée. Ce phénomène ne peut être expliqué par le seul phénomène de déshydratation dusoluté neutre par les ions environnants. Un phénomène supplémentaire de gonflement de porea été mis en évidence et corrélé à la densité de charge membranaire. La contribution des deuxphénomènes à la chute du taux de rejet du PEG a été évaluée pour différents sels à plusieursconcentrations.Le deuxième volet du travail est consacré à (i) l’évaluation de la constante diélectrique desolutions à l’intérieur de nanopores (ep) d’une membrane organique de NF (polyamide) àpartir de mesures de potentiel de membrane et (ii) la validation de cette méthode. Les valeursobtenues s’avèrent être inférieures à celle de la solution externe (effet du confinement) etdiminuer avec l’augmentation de la proportion en ions calcium du mélange (effet structurantdes ions). L’accord entre les constantes diélectriques ep déterminées à partir de mesures depotentiel de membrane et de taux de rejet ionique (mélanges ternaires) valide la cohérence dumodèle de transport utilisé (exclusion stérique, électrique et diélectrique aux interfaces) etmontre que les mesures de potentiel de membrane peuvent être envisagées pour l’évaluationcorrecte de la constante diélectrique à l’intérieur de nanopores / The complexity of transport mechanisms in nanofiltration (NF) requires the developmentof reliable modelling tools for understanding and optimizing the separation process.This study is composed of two parts. The first one focuses on the retention of a neutralsolute – poly(ethylene glycol) 600 g mol-1 (PEG) – in single solute solutions and in thepresence of mineral salts by an organic NF membrane (polyamide). Results show that PEGrejection is significantly lower in mixed-solute solutions and that rejection rate drop increaseswith salt concentration. This phenomenon cannot be imputed to only the partial dehydrationof PEG molecules by surrounding ions (salting-out effect). The additional hypothesis whichwas considered in the present work is an increase in the effective pore size (pore swelling).This hypothesis was supported by electrokinetics charge density data. The contribution ofpore swelling and salting-out to the overall decrease in the rejection rate of PEG wasevaluated for different salts at various concentrations.The second part of this study deals with (i) the determination of the dielectric constantinside pores (ep) of an NF organic membrane from membrane potential measurements and (ii)the validation of this technique. Membrane potential data were analyzed by means of theSEDE (steric, electric and dielectric exclusion) transport model. ep values were found to besmaller than the bulk value and to decrease when sodium ions were replaced by calcium ions.The agreement between ep values obtained from membrane potential measurements and thosecalculated from ion rejection rate data (ternary mixtures) highlights the global coherence ofthe transport model used and shows that membrane potential measured with electrolytemixtures can be used to determine the dielectric constant inside pores with no requirement ofadditional rejection rate measurements.

[pt] A caracterização das pressões de poros nas bacias sedimentares marinhas é fundamental dentro da etapa de planejamento dos projetos de perfuração na indústria do Petróleo. Uma vez que o desconhecimento dessas pressões coloca em risco a integridade das pessoas nas sondas de perfuração, o ambiente, além de causar grandes prejuízos para as companhias. As metodologias para a estimativa das poropressões na indústria do petróleo tiveram grande desenvolvimento a partir da década de1950. Porém, a grande maioria delas não levam em consideração caraterísticas geológicas importantes como a diagêneses das rochas, as condições de contorno para o fluxo de fluidos, e os mecanismos de dissipação das sobrepressões durante o tempo geológico. Por isso, o principal objetivo do trabalho é fortalecer os estudos convencionais de estimativa de pressão de poros incluindo uma metodologia não convencional com abordagem na modelagem de bacias. Essa metodologia permite analisar o fenômeno como um sistema dinâmico, bem como levar em consideração os mecanismos de geração e de dissipação das pressões durante a evolução geológica da Bacia. Apresenta-se a descrição dos principais mecanismos de geração de sobrepressão, a teoria que descreve o fenômeno das sobrepressões, as metodologias convencionais utilizadas na indústria do petróleo e as hipóteses da metodologia baseada na modelagem de bacias. Utilizou-se o software SEMIMT, do instituto de pesquisa da Noruega, o SINTEF, para realizar a estimativa das poropressões na Bacia de Guajira, uma região offshore do norte da Colômbia. A estimativa das pressões considerou os contornos da bacia, o modelo geológico da região, o histórico de soterramento da Bacia, bem como de modelos de compactação e os modelos de fluxo vertical e fluxo horizontal dos fluidos. O resultado da estimativa das pressões permitiu definir quatro zonas com diferente grau de sobrepressão na área em estudo, que foram comparados com uma metodologia convencional, bem com dados históricos de poços perfurados na região. / [en] Pore pressure prediction is a critical issue for well planning in the oil and gas industry. It is even more critical for offshore environments due to high risks involved in drilling operation. Blowout is the main risk regarding pore pressure since it could cause rig explosion, and oil spills to environment. Such problems can lead a successful company to a very weak position. Therefore, since the fifties, several methodologies for pore pressure prediction have been developed for the industry. Most of them just consider the mechanism of compaction as the main cause of overpressure, ignoring other factors such as rock diagenesis, boundary conditions for fluid flow, and pressure dissipation during the geologic history. That is why the main objective of this work is improving current pore pressure studies, including an alternative methodology (developed by the Norway Petroleum Research Institute - SINTEF), from a scale of basin modeling. That methodology allows analyzing the pressure phenomenon like a dynamic system, where the interaction of the overpressure and the pressure dissipation mechanisms are considered during the geological history. In this paper, main characteristics of overpressure mechanisms are briefly described as well as common methodologies used in the Oil and Gas industry for pressure prediction. Furthermore, the most important hypothesis for basing modeling methodology is described. SEMIMT software was used to predict pore pressure in Guajira Basin, an offshore region located in north Colombia. Results of basin modeling methodology allowed defining four overpressure zones which fit adequately with wells data. Besides, that result was compared with a conventional methodology. Finally, a discussion about the results is presented, highlighting the main advantages and disadvantages observed in this research.

Tamarindus indica L. é um componente natural amplamente consumido por humanos, apresentando propriedade antiinflamatória, antidiabética e antihepatotóxica. Além disso, como nós demonstramos previamente, o extrato apresenta atividade hipolipêmica e antioxidante. Neste trabalho, nós demonstramos o efeito do extrato de T. indica sobre mitocôndrias isoladas de fígado de rato. Na presença de Ca2+, o extrato causou um inchamento osmótico mitocondrial concentração-dependente, associado ao aumento da velocidade basal (V4), dissipação do potencial de membrana e liberação do Ca2+ pré-acumulado, os quais foram inibidos por ciclosporina A (CsA) e assim atribuídos a transição de permeabilidade da membrana mitocondrial (TPMM). A indução do inchamento osmótico mitocondrial foi prevenida por EGTA e vermelho de rutênio, indicando a dependência da TPMM de Ca2+. A oxidação de proteínas tiol mitocondrial, um mecanismo bem estabelecido como causador da TPMM, foi detectado. Entretanto, nenhuma alteração significante foi observada no estado redox de GSH. A oxidação de NAD(P)H e o acúmulo de espécies reativas de oxigênio produzidas pela mitocôndria foram observadas, em ambos os casos, foram prevenidas por CsA e/ou EGTA, indicando que são conseqüências da TPMM induzida pelo extrato de T. indica. Portanto, sem aparente envolvimento do estresse oxidativo no processo, sugerindo uma interação direta de compostos do extrato com grupos tiólicos de proteínas da membrana. O extrato de T. indica induziu uma depleção de ATP associada à TPMM, mostrando assim potencial para causar a morte celular por apoptose ou necrose, resultante da indução da TPMM por si ou pela depleção do ATP via TPMM. In vitro, o extrato apresentou capacidade scavenger de radicais livres, verificado pelo ensaio do DPPH, radical superóxido e radical hidroxil; e ainda foi capaz de diminuir a lipoperoxidação mitocondrial. Além disso, em baixas concentrações, o extrato mostrou uma propriedade quelante de Fe2+. / Tamarindus indica L. is a natural dietary component widely consumed by humans, presenting well established anti-inflammatory, anti-diabetic and anti-hepatotoxic properties. In addition, as we have previously demonstrated, extract presents hypolipemic and antioxidant activities. We show here the effects of T. indica extract on isolated rat liver mitochondria. In the presence of Ca2+, the extract caused mitochondrial concentration-dependent swelling, associated to, resting respiration increase (V4), membrane potential dissipation and release of pre-accumulated Ca2+, inhibited by cyclosporine A (CsA) and thus ascribable to mitochondrial permeability transition (MPT). This swelling induction was prevented by EGTA and ruthenium red, indicating strict dependence of MPT on Ca2+. Oxidation of mitochondrial membrane protein thiols, a well established mechanism causing MPT was detected. However, no significant change was observed in the GSH redox state, and the NADPH oxidation and accumulation of mitochondria-generated reactive oxygen species that was observed, were prevented by CsA and/or EGTA, indicating that they are consequence of the MPT induced by T. indica extract. Therefore, no apparent oxidative stress condition is involved as cause of this process suggesting that direct interaction with membrane protein thiol groups of the compounds responsible for MPT induction occurs. T. indica extract led to MPTassociated ATP depletion, thus showing the potential to cause cell death by apoptosis or necrosis resulting from MPT induction per se or from ATP depletion by MPT. In vitro, the extract presented free radical scavenging ability, as assessed by the 2,2-diphenyl-1- picrylhydrazyl (DPPH), superoxide radicals and radical hydroxyl assays, and led to decreased lipid peroxidation in mitochondria, as assessed by the thiobarbituric acid reactive substances (TBARS) assay. In addition, the extract showed an iron chelanting property in low concentrations.

A indústria cimenteira busca alternativas para economia de recursos no processo produtivo, em especial envolvendo o uso de materiais residuais no cimento, como escórias siderúrgicas. A escória de aciaria, em particular, apresenta composição desfavorável para aplicação in natura, porém há metodologias na literatura de modificação do material para aplicações cimentícias. No entanto, ainda não se encontram avaliações da corrosão de armaduras de aço em compósitos cimentícios com essa adição, seja em meio sólido ou líquido (água de poro). Esse estudo avaliou, através de curvas de polarização e da espectroscopia de impedância eletroquímica (EIE), a resistência à corrosão do aço CA-50 em soluções representativas de águas de poro extraídas por pressão de pastas de cimento com 25 % de escória de aciaria in natura ou modificada por processo pirometalúrgico. Para efeitos comparativos, foi feita também a avaliação do desempenho do aço em meios de águas de poro indicadas na literatura como representativas de cimento Portland comum e de escória de alto forno. O efeito da presença de espécies agressivas na resistência à corrosão do aço foi avaliado adicionando-se 1,0 % de NaCl em massa às soluções estudadas. Nas águas de poro sem 1,0 % de cloreto, o aço CA-50 apresentou-se passivo e não mostrou indícios de corrosão nos ensaios nem de polarização nem de EIE durante 120 h de imersão. Entretanto, os ajustes dos diagramas com circuito elétrico equivalente (CEE) apontaram que as características de proteção da camada passiva formada nas águas de poro de cimento com escória de aciaria foram superiores, resultando em maior resistência à corrosão do aço CA-50 nestes meios. Por sua vez, nos meios com 1,0 % de NaCl, após polarização e EIE até 120 h, o aço sofreu corrosão para as águas de poro de cimento comum e escória de alto forno, porém não corroeu nas águas de poro representativas de cimentos com escórias de aciaria, cujo melhor desempenho foi associado à maior alcalinidade destes meios. A caracterização microestrutural por microscopia eletrônica de varredura após os ensaios de polarização anódica e de imersão mostrou que o principal produto de corrosão formado foi a lepidocrocita (?-FeOOH), comum em ataque do aço por cloretos. / The cement industry seeks alternatives to save resources in production processes, especially involving the use of residual materials in cements, such as slags. Steel slags present unfavorable composition for application as cement additions in natura, but there are methodologies in the literature for modifying this material for commercial application. However, there are no evaluations of the corrosion of steel reinforcements in cementitious composites with steel slags, either in solid or liquid medium (pore water). The present study employed polarization curves and electrochemical impedance spectroscopy (EIS) to evaluate the corrosion resistance of CA-50 steel in pore water solutions representative of cement pastes with 25 % steel slag in natura or modified by a pyrometallurgical process. For comparison purposes, the performance of CA-50 steel in the pore waters indicated in the literature as representatives of Portland cement and blast furnace slag activated with cement were also evaluated. The effect of aggressive species on the corrosion resistance of the steel was assessed by adding 1.0 % NaCl by mass to the pore water solutions. Without 1.0 % chloride addition, CA-50 steel exhibited good performance and showed no evidences of corrosion in all of the investigated media, both in anodic polarization and in EIS tests performed up to 120 h immersion. However, the fitting of the EIS diagrams with equivalent electric circuit (EEC) revealed that the protectiveness of the passive layer formed in pore waters representative of cements with steel slags were superior, indicating better corrosion resistance of CA-50 steel in these media. Conversely, when 1.0 % chloride was added to the pore waters, CA-50 steel presented pitting corrosion, and impedance decreases with immersion in the pore waters representative of pure cement and blast furnace slag, whereas no corrosion was detected by both methodologies in pore waters representatives of cements with steel slags, which superior performance was ascribed to their higher alkalinity. Microstructural characterization by scanning electron microscopy (SEM) after anodic polarization and immersion tests showed that the main corrosion product formed was lepidocrocite (?-FeOOH), usual of chloride attack of steel.

Lime has been used in construction for millennia, and its value, especially in the field of conservation architecture, has only recently been rediscovered. Lime mortars harden through carbonation, and this thesis is a study of that process. The research conducted has resulted in the development of two novel techniques for the measurement and detection of carbonation. The first technique is a method of thermogravimetric analysis which allows the carbonation profile to be measured within an acceptable time-frame. The second technique is the use of drilling resistance measurement to visualise the carbonation profile. The potential of elemental analysis to measure the carbonation profile has also been identified. It has been demonstrated that the lime/water ratio has less impact on the compressive strength of air lime mortars than had previously been supposed. The change in the pore size distribution of air lime mortars caused by carbonation has been studied, and a theory has been proposed to explain this phenomenon. Five different forms of air lime binder were studied. The impact of these on the structural performance of the resultant mortars has been assessed. It was concluded that mortars made with lime putties perform better than mortars made with dry lime hydrate. Mortars made with dispersed hydrated lime appear to perform as well as mortars made with lime putties, but at a slower rate of strength growth. The use of extra mature lime putty does not appear to confer structural performance benefits when compared with ordinary lime putty. It has been shown that the use of calcitic aggregates can produce air lime mortars which perform as well as moderately hydraulic lime mortars. It is theorised that this phenomenon is not directly related to carbonation, but rather to a complex interaction of the granulometry, mineralogy, chemistry and porosity of the aggregate with the binder.

La durabilité des ouvrages en béton armé est étroitement liée à la composition des matériaux dont ils sont formés, et plus particulièrement aux propriétés de ces derniers. Cette durabilité est caractérisée par des indicateurs parmi lesquels se trouve le coefficient de diffusion des chlorures. Ceux-ci pénètrent le béton et interagissent avec les ions composant la solution interstitielle (contenue dans les pores) ainsi que les composants de la matrice cimentaire. Il existe peu de travaux dans la littérature qui décrivent toutes ces interactions ioniques de façon simultanée et encore moins leur prise en compte dans l’étude et la modélisation des transferts. Ce travail de thèse présente une étude des interactions multi-espèces se produisant lors du transfert des ions chlorure. Pour ce faire, l’évolution de la composition de la solution interstitielle, de plusieurs pâtes de ciment contenant diverses additions minérales, est étudiée. La solution interstitielle des pâtes de ciment est extraite suite à un essai de migration par pressage et analysée par chromatographie ionique. Par ailleurs, l’évolution de la microstructure de ces matériaux suite au transfert des chlorures est caractérisée par porosimétrie à intrusion de mercure (PIM) et microscopie électronique à balayage (MEB). Ceci a permis de mettre en évidence les modifications provoquées par la diffusion des ions chlorures. Dans un second temps, et afin de simuler le transfert des chlorures dans la matrice cimentaire, un modèle de transfert multi-espèces est développé. Dans ce sens, plusieurs modèles de transfert mono et multi-espèces, sous l’effet d’un champ électrique ou non, en régime stationnaire et transitoire ont été développés auparavant. L’objectif de cette partie numérique est d’étendre ces modèles à la prise en compte de l’ensemble des ions composant la solution interstitielle ainsi que leurs interactions multi-espèces conduisant à la précipitation de composés à base de chlore et à la dissolution des hydrates. La formulation mathématique des phénomènes étudiés est établie à partir de la loi de conservation de masse et les équations de la thermodynamique. Les conditions initiales et aux limites sont adaptées pour tenir compte à la fois de la composition chimique réelle de l’eau de mer et de celle de la solution interstitielle. Les résultats obtenus permettent de mettre en exergue l’effet de ces phénomènes sur la composition chimique de la solution interstitielle ainsi que sur le transfert des chlorures. / The durability of the reinforced concrete structures is closely related to the composition of their materials and, particularly to their properties. This durability is characterized by indicators among which we quote the diffusion coefficient of chlorides. These ionic species penetrate through the concrete and interact with the other species present in the interstitial solution (contained in concrete pores) as well as the cementitious matrix components. In the literature, there is a lake of data describing simultaneously these ionic interactions, especially their consideration in the study or modeling the ionic transport phenomena. This work focuses on the study of multispecies interactions that occur during the chloride transfer. To this purpose, the evolution of pore solutions chemistry of hardened cement pastes manufactured with different mineral additions is investigated. This solution is extracted, before and after migration test, using a specific press and analyzed by ionic chromatography. Furthermore, the microstructure evolution of these cement pastes is characterized by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). This allows highlighting the modification caused by chloride penetration. Secondly, for the modeling of chloride transport in cement based materials, a multispecies transport model is developed. In this context, several mono and multispecies transport models, under an electrical field or not, in transitory or steady state were developed previously. The aim of this numerical study is to extend these models in order to consider the ions present in the interstitial solution and their multispecies interactions leading to the precipitation of new chloride compound and the dissolution of some hydrates. The mathematical formulation of the phenomena studied was established from the principle of mass conservation and the thermodynamic equations. Initial and boundary conditions were adopted to take into account both the chemical composition of sea water and that of pore solution. Results highlight the effect of these phenomena on the pore solution chemistry and the chloride transport.

Ce travail concerne principalement la détermination des propriétés acoustiques de mousses. Il s’agit d’un projet mené dans le cadre d’une collaboration entre une équipe de physico-chimie des mousses chargée de l’élaboration de matériaux modèles (laboratoire Navier UMR 8205 CNRS) et une équipe d’acousticiens chargée de l’étude de leurs propriétés acoustiques (laboratoire MSME UMR 8208 CNRS). Cette thèse s’articule essentiellement autour de trois parties principales, dont le contenu est résumé ci-dessous. 1) La première partie porte sur la génération de surfaces de réponse par des approximations polynomiales, dans le but de disposer d'un modèle intermédiaire entre le modèle éléments finis micro-macro et la réponse macroscopique. Au lieu d'appeler le modèle éléments finis systématiquement dans un travail d'optimisation, on a recourt à la surface de réponse qui contient l'information associée aux points de calcul éléments finis ainsi que les interpolations correspondantes. Ce manuscrit a été publié dans le journal AAA sous forme de communication rapide. 2) La deuxième partie porte sur la mise au point d'un modèle semi-analytique définit à partir d'une formule disponible pour prédire la perméabilité d'une plaque infinie percée par un trou de surface connue. Ce modèle, utilisé de manière appropriée, permet de calculer la perméabilité de mousses dont la taille de bulles est constante et le taux de fermeture de membranes variable. Des validations numériques par éléments finis et expérimentales sont proposées. L'article a été accepté pour publication dans la revue Physical Review E. 3) La troisième partie, porte sur un calcul éléments finis dans lequel un grand nombre de réalisations sont menées de manière à prendre en compte l'ensemble des combinaisons possibles lorsque on dispose de caractérisation expérimentales fines à l'échelle de la microstructure et que l'on souhaite connaitre la réponse de la mousse avec précision. Le manuscrit est en préparation et la revue visée pour ce dernier manuscrit est le journal Materials and Design. Une introduction et une conclusion générale complètent ces trois parties, et permettent de mettre en perspectives ces contributions par rapport à la littérature existante sur le sujet / This work mainly concerns the determination of the acoustic properties of foams. This is a project carried out as part of a collaboration between a team of physico-chemistry of foams in charge of the development of model materials (Navier laboratory UMR 8205 CNRS) and a team of acousticians responsible for the study of their acoustic properties (MSME laboratory UMR 8208 CNRS). This thesis is structured around three main parts, the content of which is summarized below. 1) The first part deals with the generation of response surfaces by polynomial approximations, in order to have an intermediate model between the micro-macro finite element model and the macroscopic response. Instead of calling the finite element model systematically in an optimization work, we use the response surface that contains the information associated with finite element calculation points and the corresponding interpolations. This manuscript was published in the AAA journal as a fast track publication. 2) The second part focuses on the development of a semi-analytical model defined from an available formula to predict the permeability of a circular orifice in a thin plate. This model, used in an appropriate way, makes it possible to calculate the permeability of foams with a constant bubble size but a tuned membrane content. Numerical validations by finite element computations are proposed. The article has been accepted for publication in the journal Physical Review E. 3) The third part deals with a finite element calculation in which a large number of realizations are carried out in order to take into account all the possible combinations when one has fine experimental characterization at the microstructure scale and that one seek to determine the properties of the foam with precision. The manuscript is in preparation and a possible journal for the publication of this manuscript is the journal Materials and Design. An introduction and a general conclusion complete these three parts, and make it possible to discuss these contributions