The ability of nanoparticles to stabilize oil/water emulsions provides many interesting opportunities for the petroleum industry. Emulsions can be used as a displacing fluid for enhanced oil recovery to improve sweep efficiencies. Emulsions can be used to improve conformance control by effectively blocking thief zones in reservoirs with a high degree of heterogeneity. As shown in this thesis emulsions can be used to deliver fluids that contact and mobilize residual oil. It is imperative to understand emulsion behavior in porous media for design purposes in enhanced or improved oil recovery processes involving emulsions. Nanoparticle-stabilized oil-in-water emulsions were continuously generated by co-injecting aqueous nanoparticle dispersion and oil through a beadpack. There exists a critical shear rate below which a stable emulsion will not be generated. The critical shear rate increased with decreasing bead size. Above the critical shear rate, the droplet size of the generated emulsion was a function of shear rate and decreased with increasing shear rate. The stable emulsions were characterized by their droplet size and rheology. The emulsion viscosity was highly dependent upon droplet size and not the bulk oil viscosity in the emulsion. The emulsions were highly shear thinning and emulsions with smaller droplets were more viscous than emulsions with larger droplets. Highly stable emulsions that were generated by co-injection were collected, separated from excess phase(s) and injected into beadpacks. In most experiments the injected emulsion coalesced into the bulk fluids. Whether the bulk fluids generated a new emulsion in the bead pack depended on the shear rate, bead size, and initial saturation of the beadpack. Different beadpack experiments showed the transition from one flow regime to a second flow regime as the slow movement of a coalescence/regeneration front propagated through the beadpack. Coreflood experiments confirmed the mechanisms hypothesized for the beadpack emulsion injection experiments. When a stable emulsion was injected the effluent emulsion rheology and droplet size were altered solely as a result of being forced through sandstone cores, not because of fluids contacted within the core. The shear rate controlled whether the emulsion coalesced and produced no effluent emulsion, regenerated into an emulsion with larger droplets, or regenerated into an emulsion with smaller droplets. Oil recovery experiments showed that nanoparticle-stabilized oil-in-water emulsion increased the recovery of oil compared to a waterflood for cores with immobile and mobile oil. The mechanism is the coalesced oil droplets form a flowing phase that is miscible with oil present in the core and thus achieves a much more efficient displacement. The possible continuous generation and coalescence of droplets may have increased the apparent viscosity, improving the sweep efficiency of the emulsion injection. A novel oil recovery mechanism was shown in imbibition experiments where nanoparticle dispersion was used to displace oil. Large shear rates coupled with the affinity for nanoparticles at the oil water interface enabled residual oil to be mobilized, or for residual oil blobs to spawn smaller droplets that are stabilized by the nanoparticles and thus can be transported with the dispersion through the core. / text

Les émulsions de type huile-dans-eau jouent un rôle important lors des opérations de ré-injection des eaux de production (PWRI). Ce travail s'intéresse à l'écoulement /rétention de ce type d'émulsions en milieux poreux et à leur impact sur l'injectivité. Deux mécanismes fondamentaux sont distingué selon la valeur du Jamming ratio Jr (taille des restrictions /taille des gouttes): le dépôt dit de surface aux forts Jr et le "straining" (blocage, par le forces capillaires, d'une ou plusieurs gouttes à l'amont d'une restriction) aux faibles Jr.Ce document traite, d'abord, de la physicochimie du dépôt de surface. L'étude en fonction de différents paramètres, tels que la salinité et le débit, permis de décrire la structure et la cinétique du dépôt. Nous avons notamment mis en évidence la formation d'une monocouche compacte é gouttelettes individuelles et montré que la cinétique du dépôt vérifie les lois d'échelle développées pour les colloïdes. L'ensemble de nos résulta conforte la similarité de comportement entre les émulsions stables et diluées et les systèmes colloïdaux.Ensuite, le "straining" est mis en évidence et discuté en fonction des distributions en taille -des restrictions et des gouttes- et des valeurs du nombi capillaire.Enfin, nous avons établi que l'endommagement associé au dépôt de surface peut être très significatif et que les pertes d'injectivité sont prédictibles par une loi de Poiseuille modifiée. Pour le "straining", l'impact est encore plus sévère mais sa vitesse de propagation est plus lente.En conclusion, l'effet de ce type d'émulsion doit être pris en compte pour minimiser les risques et optimiser le schéma de réinjection.

No description available.

Ionomers are valued for their exceptional physical properties, antimicrobial activity and superior adhesion to high surface energy solids and polymer blend components. Carboxylate, or sulfonate derivatives, of ethylene-rich thermoplastics are the most commercially available ionomers. Elastomeric ionomers bearing quaternary ammonium and phosphonium halide functionality have a literary standing in both scientific and patent-based publications. Currently cationic ionomers have shown great prominence in their inactivity to a wide range of bacteria and fungi. The specific focus of this research is in the derivatives of isobutylene-rich elastomers due to their exceptional impermeability, oxidative stability and vibration dampening characteristics. Imidazole-derived ionomers support a wider range of ionomer chemistry compared to ammonium and phosphonium analogues. N alkylation of nucleophiles including butyl imidazole, vinyl imidazole and 1,1’(1,4-butanediyl)bis(imidazole) by brominated poly(isobutylene-co-isoprene) yield thermally stable imidazolium bromide salts capable of supporting free radical cures and/or siliceous filler dispersions through further chemical modifications. The versatility of imidazole chemistry extends to the synthesis of isobutylene rich thermoset ionomers. This derives material properties from both a network of covalent crosslinks and a network of ion pair aggregates. Un-crosslinked elastomers are prone to creep and stress relaxation, hence a need for thermoset ionomer chemistry. Ion pairs are poorly solvated by the low dielectric constant of the polymer backbone and favoured thermodynamically by way of self assembly of the ionic functionality. The aggregation of ion pairs establishes a non covalent network of polymer chains whose dynamic mechanical properties approach those of conventional covalent thermosets comprised of carbon-carbon and/or sulfide crosslinks. However, the lability of this ionic network leads to a poor response to static loads leaving the thermoformable ionomers unqualified for engineering applications. A direct route is a more desirable method in preparing thermoset ionomers comprised of covalent crosslink networks and ionic functionality. In all, these reactive imidazolium ionomers look promising in supporting new value added applications for isobutylene rich derivatives, which include yet are not limited to elastomer thermosets, emulsions, filler composites and clay nanocomposites. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2013-12-11 15:34:32.691

The overall goal of this research was to develop a plant protein-based microcapsule capable of carrying, protecting and delivering flaxseed oil within the food and gastrointestinal environment. Specifically, the research aimed to: a) screen a variety of plant proteins and pre-treatment conditions based on their emulsifying properties for use as a wall material; b) develop and optimize encapsulation protocols for entrapping flaxseed oil; and c) study the oxidative stability and delivery of entrapped oils from capsules under different environmental and simulated gastrointestinal conditions. In Chapter 3 and 4, the emulsifying and physicochemical properties of legume and oilseed protein isolates, respectively produced from isoelectric precipitation and salt extraction were investigated. Findings in Chapter 3 indicated that both the legume source and method of production showed significant effects on the emulsifying and physicochemical properties of chickpea (ChPI), faba bean (FbPI), lentil (LPI), pea (PPI), and soy (SPI) protein isolates. The emulsion capacity (EC) values ranged between 476-542 g oil/g protein with LPI showing the highest capacity. Isoelectric-precipitated ChPI and LPI displayed higher emulsion activity index (EAI) (~46.2 m2/g), (emulsion stability index) ESI (~84.9 min) and (creaming stability) CS (98.6%), which were comparable to those of SPI. In Chapter 4, findings indicated that both protein source and method of production had significant effects on the physicochemical and emulsifying properties of canola (CaPI) and flaxseed protein isolates (FlPI). CaPI showed significantly higher EC (~515.6 g oil/g protein) than FlPI (~498.9 g oil/g protein). EAI for FlPI was found to be higher (~40.1 m2/g) than CaPI (~25.1 m2/g) however, ESI values of CaPI and FlPI were similar. Creaming stability of emulsions stabilized by CaPI and FlPI ranged between 86.1 and 96.6%. CaPI and FlPI were shown to have emulsion forming properties; however their stability was low. In Chapter 5, ChPI and LPI-stabilized emulsions were optimized based on pH, protein concentration and oil content for their ability to form and stabilize oil-in-water emulsions using response surface methodology. Droplet charge was shown to be only affected by pH, while droplet size and creaming index were affected by protein concentration, oil content and pH. Optimum conditions for minimal creaming (no serum separation after 24 h), small droplet size (<2 μm), and high net droplet charge (absolute zeta potential (ZP) value >40 mV) were identified as: 4.1% protein, 40.0% oil, and pH 3.0 or 8.0, regardless of the plant protein used for emulsion preparation. Flaxseed oil was microencapsulated by freeze (Chapter 6) or spray (Chapter 7) drying employing ChPI or LPI and maltodextrin. Effects of emulsion formulation (oil, protein and maltodextrin levels) and protein source (ChPI vs. LPI) on the physicochemical characteristics, oxidative stability, and release properties of the resulting capsules were investigated. Optimized capsule designs were found to have high encapsulation efficiencies, low surface oil, and afforded protection against oxidation over a 25 d room temperature storage study relative to free oil. Microcapsules were also able to deliver 84.2% of the encapsulated oil in the simulated gastrointestinal environments.

Não Consta Resumo na Publicação / Abstracts Not Available

Não Consta Resumo na Publicação / Abstracts Not Available

O processo de separação da água em emulsões de petróleo é feita durante o processamento primário do petróleo e consiste na coalescência de gotas de água. Para minimizar o uso de desemulsificantes e acelerar o processo de separação da emulsão alguns equipamentos podem ser utilizados como os separadores acústicos. Neste trabalho a técnica de força de radiação produzida por ondas estacionárias de ultrassom é aplicada na segregação das fases líquidas de emulsões água em óleo. São desenvolvidas células de ultrassom que operam em frequências próximas de 1 MHz através de ressonadores piezelétricos visando a aplicação na coalescência de gotas de água em emulsões do tipo água-óleo. O trabalho envolve simulações do campo acústico através de modelos analíticos unidimensionais e bidimensionais e de um modelo numérico bidimensional pelo método dos elementos finitos para o estado plano de deformações. São realizadas verificações experimentais em protótipos de células de alta potência para separação em batelada através da comparação do potencial de radiação acústica e da impedância elétrica com resultados de modelos computacionais. Diversos ensaios de quebra de emulsões sintetizadas de petróleo são realizados utilizando um aparato experimental de laboratório aplicando potências de até 600 W=l. Um sistema de controle de frequência de operação é implementado para manter máxima transmissão de potência elétrica para a célula. Os resultados mostraram que a técnica empregada pode reduzir pela metade o uso de desemulsificante químico (de 20 a 10 ppm) ou diminuir o tempo de residência em até 60% (de 20 para 8 min). Uma análise da influência da frequência na eficiência de desemulsificação é realizada e indica que não há sensibilidade no resultado para a faixa de frequência entre 0.8 e 1.5 MHz a uma temperatura ambiente de aproximadamente 23 C. A metodologia empregada auxilia no projeto das células e na aplicação da técnica, mas é insuficiente para explicar integralmente os mecanismos de separação e as diferenças entre o protótipo e o modelo. A aplicação de ultrassom na coalescência de emulsões possui potencial para desenvolvimento em larga escala. / The oil water separation process of petroleum emulsions is performed during the primary processing of crude oil and consists of water droplets coalescence. To minimize the use of demulsifiers and accelerate the emulsion separation process some equipment may be used such as acoustic separators. In this work, a radiation force technique produced by ultrasound standing waves is applied to the water phase separation in oil emulsions. Ultrasound cells operating at ultrasonic frequencies near 1 MHz are developed using piezoelectric resonators applied to the coalescence of water droplets in oil emulsions. This work involves simulations of the acoustic field through one-dimensional and two-dimensional analytical models and a numerical model for two-dimensional plane strain finite element analysis. Furthermore, experimental verification is performed using high power prototypes for batch separation by comparing the acoustic radiation potential and electrical impedance with computational models results. Several tests of synthesized petroleum emulsions breaking are performed using an experimental laboratory apparatus applying up to 600 W=l. A frequency control system is implemented in order to maintain maximum electric power transmission to the cells. The results showed that the technique can halve the use of chemical demulsifier (from 20 to 10 ppm) or decrease the residence time of up to 60% (from 20 to 8 min). An analysis of the frequency influence on demulsification efficiency is performed and indicates that there is no parameter sensitivity in the frequency range between 0.8 and 1.5 MHz at room temperature of approximately 23 C. It is demonstrated that the design methodology is consistent and the application has potential for large-scale development.

Hidrolisados proteicos possuem propriedades terapêuticas e são absorvidos mais facilmente pelo organismo quando comparados às proteínas, no entanto sua aplicação em alimentos é dificultada por serem higroscópicos, reativos e apresentarem gosto amargo. A microencapsulação por spray chilling pode ser uma alternativa para solucionar essas limitações. Este método de encapsulação consiste na atomização de uma mistura, formada pela dispersão ou emulsão do material ativo com o carreador fundido, em uma câmara com temperatura inferior ao ponto de fusão do carreador, que nessas condições solidifica, formando micropartículas esféricas. O objetivo deste trabalho foi elaborar micropartículas de hidrolisado de proteína de soja utilizando o método de spray chilling e gordura vegetal (PF 51°C) como carreador. Foram realizados ensaios para obtenção das micropartículas avaliando a alimentação por emulsão e dispersãoe diferentes formulações variando a proporção material ativo:encapsulante (1:5 e 1:10), velocidades de rotação no ultra-turrax (6000 e 8000 rpm) e três diferentes temperaturas (60, 70 e 80°C), totalizando dezoito tratamentos. As misturas foram submetidas à análise reológica para determinação de viscosidade e após serem atomizadas em spray chiller as micropartículas obtidas foram caracterizadas por FTIR, Difração de Raio-X, distribuição e tamanho médio por difração a laser e morfologia por microscopia eletrônica de varredura e confocal. Foram obtidas micropartículas lipídicas sólidas esféricas e aglomeradas, o tamanho médio variou de 53,06 &plusmn; 2,17 &micro;m e 68,03 &plusmn; 14,07 &micro;m, sem diferenças significativas entre os tratamentos. Partículas obtidas pela atomização da emulsão apresentaram poros, todavia exibiram maior capacidade de carregamento do hidrolisado, cerca de 96%, enquanto as obtidas por dispersão apresentaram 54%. Variações durante o preparo da emulsão não proporcionaram alterações na morfologia e tamanho de partícula nas micropartículas, apesar de terem tido influência sobre as propriedades reológicas do sistema. A análise de difração de raios-X indicou que as micropartículas após 90 dias de preparo apresentaram a estrutura na forma polimórfica mais estável. A espectroscopia na região do infravermelho (FTIR) revelou que não ocorreu interação entre os ingredientes independentemente do modo de preparo das micropartículas. Tais resultados demonstram que a técnica de spray chilling é eficiente na microencapsulação de hidrolisado proteico de soja, possibilitando uma futura aplicação em alimentos. / Protein hydrolysates possess therapeutic properties and absorption easier than to proteins; however its application in food is limited due to its bitter taste, hygroscopic and reactivity. Encapsulation byspray chilling could be an alternative to minimize these limitations. This method consists in the atomization of a mixture formed by the dispersion or emulsion of the active material with the molten carrier, into an environment with temperature below the melting point of the carrier, under these conditions it solidifies to form spherical microparticles. The aim of this work was to develop microparticles loaded with hydrolyzed soy protein using the method of spray chilling and vegetable fat (PF 51°C) as carrier. Tests were conducted to obtain microparticles evaluating the feed by emulsion and dispersion and different formulations by varying the proportions active materials:carrier (1:5 and 1:10), homogenization speed by Ultra-Turrax (6000 and 8000 rpm) and temperature (60, 70 and 80°C ), totaling eighteen treatments. The mixtures were subjected to rheological analysis for determination of viscosity and after being atomized at spray chiller obtained microparticles were characterized by infrared spectroscopy and X-ray diffraction, particle size distribution and mean diameter measured using a laser light diffraction instrument and morphology was observed by scanning electron microscopy (SEM) and confocal microscopy. Solid lipid microparticles obtained were spherical and agglomerated the average size between 53.06 &plusmn; 2.17 &micro;m and 68.03 &plusmn; 14.07 &micro;m, there was no significant difference between formulations. Particles obtained by atomization of emulsion had presence of pores, but exhibited a higher loading capacity of the hydrolyzed, about 96%, while that obtained by dispersion had 54%. Changes during the preparation of the emulsion no provided changes at morphology and particle size of the microparticles, despite having influence on the rheological properties of the system. The analysis of X-ray diffraction showed that the microparticles after 90 days of storage had &beta; polymorphic form. The infrared spectroscopy (FTIR) showed that there was no interaction between the ingredients regardless of the mode of preparation of the microparticles. These results demonstrate that the technique spray chilling is efficient in microencapsulation of soy protein hydrolyzate, allowing future use in foods.

Les émulsions de type huile-dans-eau jouent un rôle important lors des opérations de ré-injection des eaux de production (PWRI). Ce travail s'intéresse à l'écoulement /rétention de ce type d'émulsions en milieux poreux et à leur impact sur l'injectivité. Deux mécanismes fondamentaux sont distingué selon la valeur du Jamming ratio Jr (taille des restrictions /taille des gouttes): le dépôt dit de surface aux forts Jr et le «straining» (blocage, par le forces capillaires, d'une ou plusieurs gouttes à l'amont d'une restriction) aux faibles Jr.Ce document traite, d'abord, de la physicochimie du dépôt de surface. L'étude en fonction de différents paramètres, tels que la salinité et le débit, permis de décrire la structure et la cinétique du dépôt. Nous avons notamment mis en évidence la formation d'une monocouche compacte é gouttelettes individuelles et montré que la cinétique du dépôt vérifie les lois d'échelle développées pour les colloïdes. L'ensemble de nos résulta conforte la similarité de comportement entre les émulsions stables et diluées et les systèmes colloïdaux.Ensuite, le «straining» est mis en évidence et discuté en fonction des distributions en taille -des restrictions et des gouttes- et des valeurs du nombi capillaire.Enfin, nous avons établi que l'endommagement associé au dépôt de surface peut être très significatif et que les pertes d'injectivité sont prédictibles par une loi de Poiseuille modifiée. Pour le «straining», l'impact est encore plus sévère mais sa vitesse de propagation est plus lente.En conclusion, l'effet de ce type d'émulsion doit être pris en compte pour minimiser les risques et optimiser le schéma de réinjection. / The O/W emulsions are major actors in the operations of produced water reinjection (PWRI). This work focuses on the flow/retention of these specific emulsions in porous media and their impact on injectivity. Two fundamental mechanisms are considered according to the jamming ration Jr, that is to say the pore throat to droplet size ratio. At high Jr, surface retention is operative, whereas at small ones, it is the "straining" which describes the upstream clogging of a pore throat by one or more droplets because of the capillary forces.This report firstly targets the physicochemistry of the surface deposit. Several parameters were checked, such as salinity and flow rate, and allow us to descrïbe the deposit structure and the deposition kinetics. We evidenced the formation of a dense monolayer of individual oil droplets and showed that the deposition kinetïcs follows the scaling power laws initially developed for colloids. It clearly underlines the similar behaviour of stable emulsion anc other colloidal systems.Then, the straining was observed and discussed according to size distributions of botte droplets and pore throats and also according to the capillary number.Finally, we established that the injectivity losses caused by surface retention can be very significant and that they are predictable through a modified Poiseuille's law. Concerning the "straining", the impact is even more severe but its propagation rate is far smaller.To conclude, the effects of these emulsions have to be taken into account to minimise the risks and optimise the reinjection scheme.