A large number of commercial and some novel Brunel synthesised surfactants have been studied with a view to their potential usefulness for enhanced oil recovery (EOR) application. Ethoxylated phenols and their sulphonated derivatives were given especially high priority. The surfactants were well-characterised in order to understand their EOR potential. High pressure liquid chromatography, mass spectrometry, Raman spectrometry, nuclear magnetic resonance spectrometry and other quantitative techniques were used. Aspects of their behaviour (as single components and as blends with co-surfactants and co-solvents) which have been considered in terms of: (i) phase behaviour with brine and hydrocarbons (ii) adsorption onto various oxide surfaces (iii) interfacial properties such as surface tension, wetting, contact angles and viscosity (iv) stability Three different blends using sulphonated surfactants which: (i) produce a microeinulsion which is stable to high salinity brines over a large temperature range (ii) exhibit low adsorption onto reservoir rock (iii) interfacial tension as low as 10-2mNm-1 have been subsequently optimised. Core flooding tests carried out under reservoir conditions produced an additional 20% of the original-oil-in-place.

Water-in-oil (w/o) microemulsion systems, stabilised by either an anionic surfactant or a cationic surfactant were studied. The anionic system consisted of ethoxylated nonylphenol phosphate esters (Atpol), Shellsol oil and an alcohol. These microemulsions tolerated an increase in ionic strength of the water phase up to a point: Beyond this point no microemulsion could be obtained. However, adding amine salts, e.g. diethanolamine nitrite, improved the emulsification of the aqueous phase. Increasing the alcohol (cosurfactant) chain length up to octanol also increased the uptake of the aqueous phase. Thus octanol yielded the best results in terms of emulsifying large volumes of the water-phase, particularly at high salt concentrations. A key objective was to prepare stable microemulsions with high nitrite content. The maximum microemulsion nitrite contents (expressed as NaNO2equivalent by mass) achieved were: -- About 10% when a 30% NaNO2solution was emulsified -- 23% when neat diethyl ethanolamine nitrite (DEEAN) was solubilized, and -- 23% for mixtures of diethanolamine nitrite (DEtOHAN) and NaNO2 in water. The cationic microemulsion system was based on the double-chain cationic surfactant, didodecyldimethyl ammonium chloride (DDAC). In this case the solubilization of the following acetate salts were investigated: ammonium, sodium, magnesium, zinc and manganese. As with the Atpol system, it was found that increasing the ionic strength is detrimental to microemulsification of the aqueous phase. In the DDAC system, an increase in the alcohol chain length beyond butanol led to reduced aqueous phase uptake. Thus the natures and concentrations of the surfactant and the cosurfactant as well as the ionic strength of the aqueous phase determine the stability and the emulsification of large volumes of aqueous phase. In general there is an optimum ionic strength at which the salt content of the microemulsion formulation is maximised. / Dissertation (MSc (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19234号 / 工博第4069号 / 新制||工||1628(附属図書館) / 32233 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 渡辺 宏, 教授 古賀 毅, 教授 金谷 利治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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Functionalized membranes provide an elegant platform for selective separations and sorptions. In this dissertation, application of functionalized membranes for surfactant and metal sorption studies are discussed. Sorption behavior of surfactants is also studied using quartz crystal microbalance (QCM) and other techniques. Adsorption of the ethoxylated surfactants on polymeric materials (cotton and polyester) and model gold surface was quantified from a non-aqueous siloxane based solvent (D5) and water. The role of ethylene oxide group and the effect of nature of polymeric materials on adsorption behavior was quantified and established. In the case of gold-water interface, the adsorption data was fitted to calculate adsorption/desorption rate constants. The study is important towards applications involving use of the surfactants in cleaning operations. PAA functionalized membranes were prepared and used for separation of the surfactants from the siloxane solvent. Finally the pH sensitivity of the PAA-surfactant complex was verified by successful regeneration of the membrane on permeation of slightly alkaline water. The preparation and application of thiol and sulfonic acid functionalized silica mixed matrix membranes for aqueous phase metal ion sorption is also studied. The functionalized particles were used as the dispersed phase in the polysulfone or cellulose acetate polymer matrix. The effects of the silica properties such as particle size, specific surface area, and porous/nonporous morphology on the metal ion sorption capacity were studied. Silver and ferrous ions were studied for metal sorption capacities. The ferrous ions were further reduced to prepare membrane immobilized iron nanoparticles which are attractive for catalytic applications. One dimensional unsteady state model with overall volumetric mass transfer coefficient was developed to model the metal ion sorption using mixed matrix membrane. The study demonstrates successful application of the functionalized mixed matrix membranes for aqueous phase metal capture with high capacity at low transmembrane pressures. The technique can be easily extended to other applications by altering the functionalized groups on the silica particles. The study is important towards water treatment applications and preparation of membrane immobilized metal nanoparticles for catalytic applications.

Foi desenvolvido modelo matemático para o processo de produção de álcoois etoxilados em um reator batelada com spray da fase líquida na fase gasosa. O modelo considera a cinética da polimerização iônica e a transferência de massa de óxido de eteno entre as fases gasosa e líquida. A cinética foi estudada a partir de dados previamente obtidos em laboratório. Para modelagem da transferência de massa, foram utilizados dados de bateladas industriais. Foram testados vários modelos de transferência de massa encontrados na literatura, sendo que o modelo que se mostrou mais adequado para este reator industrial foi o de gotas com circulação interna. A partir do modelo obtido da cinética e da transferência de massa, foi analisada a influência de parâmetros de projeto, como a vazão de recirculação de líquido, a relação entre a altura e o raio do reator e o tipo de spray na produtividade deste. Observou-se que a maior vazão de recirculação aumenta a produtividade do reator, assim como o aumento da altura do reator. O tipo e o diâmetro da gota do spray também influenciam a produtividade do reator. / A mathematical model for the production of ethoxylated alcohols in a spray tower loop reactor was developed. The model considers the reaction as an ionic polymerization and the ethylene oxide mass transfer from the vapor phase to the liquid phase. The kinetics was obtained from a laboratory scale reactor data. The mass transfer model was obtained from the industrial reactor data. Several models for the mass transfer of ethylene oxide from gas phase to the liquid droplets were tested, and it was found that the most appropriate mass transfer model for this industrial reactor was the internally well-mixed drop model. From the kinetics and the mass transfer model, the influence of the pump recirculation flow rate, the ratio between the reactor height and radius and the spray performance was analyzed. The results show that higher reactor productivity can be obtained using higher recirculation flow and higher reactor height. The spray nozzle performance and the drop diameter also influence the reactor productivity.

Foi desenvolvido modelo matemático para o processo de produção de álcoois etoxilados em um reator batelada com spray da fase líquida na fase gasosa. O modelo considera a cinética da polimerização iônica e a transferência de massa de óxido de eteno entre as fases gasosa e líquida. A cinética foi estudada a partir de dados previamente obtidos em laboratório. Para modelagem da transferência de massa, foram utilizados dados de bateladas industriais. Foram testados vários modelos de transferência de massa encontrados na literatura, sendo que o modelo que se mostrou mais adequado para este reator industrial foi o de gotas com circulação interna. A partir do modelo obtido da cinética e da transferência de massa, foi analisada a influência de parâmetros de projeto, como a vazão de recirculação de líquido, a relação entre a altura e o raio do reator e o tipo de spray na produtividade deste. Observou-se que a maior vazão de recirculação aumenta a produtividade do reator, assim como o aumento da altura do reator. O tipo e o diâmetro da gota do spray também influenciam a produtividade do reator. / A mathematical model for the production of ethoxylated alcohols in a spray tower loop reactor was developed. The model considers the reaction as an ionic polymerization and the ethylene oxide mass transfer from the vapor phase to the liquid phase. The kinetics was obtained from a laboratory scale reactor data. The mass transfer model was obtained from the industrial reactor data. Several models for the mass transfer of ethylene oxide from gas phase to the liquid droplets were tested, and it was found that the most appropriate mass transfer model for this industrial reactor was the internally well-mixed drop model. From the kinetics and the mass transfer model, the influence of the pump recirculation flow rate, the ratio between the reactor height and radius and the spray performance was analyzed. The results show that higher reactor productivity can be obtained using higher recirculation flow and higher reactor height. The spray nozzle performance and the drop diameter also influence the reactor productivity.

La filière OLED (diode électroluminescente organique) est depuis quelques annéesfortement industrialisée notamment depuis leur utilisation dans les smartphones et les téléviseurs.Cependant, les procédés de fabrication, notamment l’évaporation thermique sous vide, restent coûteuxet ne peuvent pas être utilisés pour développer des applications à faible valeur ajoutée (petitsafficheurs, signalétique, éclairage). Ces travaux de thèse ont pour objectif de développer une OLEDperformante et stable fabriquée à coût réduit afin de répondre à cette problématique. La voie liquide aété privilégiée afin de diminuer les coûts de fabrication de l’OLED et il a été choisi de développer unestructure inverse pour améliorer la stabilité. Dans ce travail de thèse, le polymère PEIE(polyéthylénimine éthoxylate) a été utilisé pour diminuer le travail de sortie de la cathode transparente.Nous avons montré qu’il était possible d’atteindre des performances supérieures en structure inversequ’en structure conventionnelle à partir du même polymère émissif, le Super Yellow. Afin desimplifier le procédé de dépôt, nous avons montré qu’un mélange binaire {PEIE et matériau bloqueurde trous} pouvait être déposé en une seule fois tout en conservant un fonctionnement optimal. Uneétude par TOF-SIMS (Spectrométrie de Masse d’Ions Secondaires à Temps de Vol) a permis de mettreen évidence une ségrégation verticale du mélange binaire. Par ailleurs, l’électrode en oxyde d’étainindium(ITO), qui représente généralement plus d’un quart du coût de fabrication, a été remplacéeavec succès par une électrode de SnO2 (oxyde d’étain), déposée par ALD (dépôt de couches mincesatomiques). / OLED (Organic Light-Emitting Diode) technology has been exploited on an industrialscale for several years, principally in smartphones, TV displays, and similar devices. However, currentfabrication processes, such as thermal evaporation under high vacuum, are expensive and cannot beused for low-cost applications (signage, lighting, etc.). This work aims to develop high-performance,stable, low-cost OLEDs. Fabrication by solution processing was chosen to reduce the processing costsin any future commercialization of the work, while the inverted architecture was used to optimizedevice stability. In this work, ethoxylated polyethylenimine (PEIE) was used to reduce the workfunction of the transparent cathode. It was shown that higher performances could be obtained withinverted OLEDs compared to direct devices incorporating the same emissive polymer (Super Yellow).Furthermore, it was demonstrated that a binary blend, (PEIE and a hole blocking material) could bedeposited in a single step without reducing the OLED device’s performance – greatly simplifying thefabrication process. A TOF-SIMS (Time of Flight-Secondary Ion Mass Spectrometry) study wasconducted which demonstrated a vertical phase segregation of the binary blend. Finally, the indiumtinoxide (ITO) electrode, which represents at least 25% of the fabrication cost, was successfullyreplaced with a tin oxide (SnO2) layer, deposited by ALD (Atomic Layer Deposition).

[pt] Cristais líquidos são formados em alta concentração de surfactantes e apresentam muitas propriedades interessantes como a auto-organização, alta capacidade de incorporação de substâncias hidrofóbicas, propriedades reológicas únicas, além de conservarem as propriedades úteis e versáteis dos surfactantes. Entretanto, devido sua alta viscosidade, são inviáveis para determinadas aplicações, como por sprays e por injeções, por exemplo. Portanto, o objetivo principal deste trabalho é dispersar e estabilizar os cristais líquidos sob a forma de partículas em meio aquoso, que sejam capazes de encapsular óleos e ou substâncias hidrofóbicas, mantendo. Para isso, diferentes sistemas foram preparados combinando surfactantes iônicos, álcoois graxos e surfactantes não-iônicos etoxilados, com diferentes comprimentos de cadeias. A adição de álcoois graxos a surfactantes iônicos já é comumente usada para garantir a formação de cristais líquidos de estrutura lamelar. E a adição de surfactantes etoxilados foi realizada como uma tentativa de promover a dispersão dos cristais líquidos na forma de partículas em água. Isso se daria graças às cadeias etoxiladas hidrofílicas que poderiam se estender em direção ao meio aquoso, garantindo uma alta estabilização. Para o planejamento otimizado destes sistemas, primeiramente foi realizado um estudo de caracterização das estruturas formadas entre os pares dos reagentes em água, que permitiu compreender o efeito das diferentes proporções entre eles. A partir disso, algumas composições foram selecionadas para o preparo e caracterização das dispersões de partículas líquido-cristalinas. Os resultados de espalhamento de raios X a baixos ângulos e microscopia óptica confirmaram a estrutura líquido-cristalina lamelar, forneceram informações sobre a morfologia e dimensões das partículas. Por fim, foram realizados testes que confirmaram a capacidade de incorporação de óleo mineral pelas partículas selecionadas. Estes sistemas possuem a vantagem de serem preparados com substâncias já amplamente utilizadas na indústria de cosméticos. Desta forma, se confirmado o potencial de aplicação para liberação controlada, poderiam ser facilmente direcionados para aplicações em escala industrial com matérias primas de fácil acesso, com bastante disponibilidade comercialmente e custos relativamente baixos. / [en] Liquid crystals are formed in high concentration of surfactants and present many interesting properties such as self-organization, high uptake capacity of hydrophobic substances, unique rheological properties, despite of keeping the useful and versatile properties of surfactants. However, due to their high viscosity, they are inadequate to certain applications, such as spraying or injections. Hence, the main objective of this work is dispersing and stabilizing liquid crystals in the shape of particles in aqueous medium, being capable of encapsulate oils and or hydrophobic substances. For this, different systems were prepared by combining ionic surfactants, fatty alcohols and ethoxylated non-ionic surfactants, with different chain lengths. The addition of fatty alcohols to ionic surfactants is commonly used to guarantee the formation of liquid crystals with lamellar structure. And the addition of ethoxylated surfactants was performed as an attempt to promote the dispersion of liquid crystal in the shape of particles in water. It should occur due to the hydrophilic chains of ethylene oxide, which could extend towards the aqueous medium, guaranteeing high stability. To optimize the design of the systems, first, a study was performed to characterize the structures formed by the pairs of reactants in water, allowing to comprehend the effect of different proportions between them. From that, some compositions were selected to the preparation and characterization of dispersions of liquid-crystalline particles. The results of Small Angle X-Ray Scattering and optical microscopy confirmed the lamellar liquid-crystalline structure and provided information about the morphology and dimensions of the particles. Finally, tests were performed to confirm the capacity of uptake mineral oil by the selected particles. These systems possess the advantage of being prepared with substances widely used in the cosmetics industry. Thus, if the potential application to controlled delivery is confirmed, they could easily be directed to applications in industrial scale with easily accessible raw materials, with plenty of commercial availability and relatively low costs.

Neste trabalho, realizamos um estudo das propriedades estruturais e elásticas da fase lamelar e também das interações relevantes que levam à estabilização dessa estrutura periódica. A composição da membrana, assim como sua hidratação, foi variada de maneira sistemática com o objetivo de introduzir alterações na flexibilidade da bicamada e no regime de confinamento. A fase lamelar é constituída de lecitina à qual é incorporado, em diferentes proporções, um co-surfactante comercial, formado por uma mistura de ácidos graxos etoxilados, Para o estudo das interações entre as bicamadas a fase lamelar foi submetida a uma pressão osmótica conhecida. Por meio de experimentos de SAXS, foram determinados os parâmetros estruturais que caracterizam a fase lamelar, para um dado valor de pressão. Os resultados experimentais obtidos são ajustados considerando-se um potencial efetivo de interação entre as bicamadas, permitindo a determinação de parâmetros quantitativos, caracterizando as diferentes contribuições atrativa e repulsivas. Em um segundo momento, foi realizado um estudo para caracterização da fase lamelar, desta vez, introduzindo um co-surfactante não comercial com o objetivo de investigar as alterações que ocorrem na interface devido à presença dos grupos etoxilados. Observa-se que a incorporação do co-surfactante amplia o domínio de diluição da fase lamelar atingindo período em torno de 200 Å, sem domínios de coexistência de duas fases lamelares, como se observa com o co-surfactante comercial polidisperso. O uso de um produto mais bem caracterizado, permite observações mais claras sobre mudanças no comportamento do parâmetro de Caillé, que caracteriza a flexibilidade da membrana, assim como alterações que ocorrem na interface, seja por efeito de confinamento ou por efeito de temperatura. / In this work, we carried out a study of structural and elastic properties of the lamellar phase and the relevant interactions that lead to stabilization of this periodic structure. The composition of the membrane, as well as hydration, was varied systematically in order to introduce changes in the flexibility of the bilayer and confinement regime. The lamellar phase is composed by lecithin, in which is incorporated in different proportions a commercial co-surfactant consisting of a mixture of ethoxylated fatty acids, To study the interactions between the bilayers the lamellar phase was placed under a known osmotic pressure. Structural parameters characterizing the lamellar phase were determined by SAXS experiments, for a given value of pressure. The experimental results are fitted considering an effective potential of interaction between the bilayers, allowing the determination of quantitative parameters characterizing the different attractive and repulsive contributions. In a second step, studies for characterization of the lamellar phase were carried out, but at this time, introducing a non-commercial co-surfactant with the aim of investigating the changes that occur at the interface due to the presence of ethoxylated groups. It is observed that the incorporation of co-surfactant extends the dilution limit of the lamellar phase, reaching lamellar periodicities around 200 Å, without coexistence of two lamellar phases, as observed with the commercial polydisperse co-surfactant. Using a more well characterized product, it is clearer the changes on the behavior of Caillé parameter, which characterizes the flexibility of the membrane, as well as changes occurring at the interface, either by confinement or temperature effects.