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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Uticaj molekularnih svojstava maltodekstrina na tehnološko ponašanje niskoenergetskih prehrambenih emulzija / Influence of molecular characteristics of maltodextrins on technological behaviour of low-energy food emulsions

Dokić-Baucal Ljubica 10 May 2002 (has links)
<p>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</p><p>Maltodekstini, hidrolizati skroba niskog stepena konverzije (dekstrozni ekvivalent manji od 20), imaju &scaron;iroku upotrebu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U prehrambenoj industriji koriste se u niskoenergetskim prehrambenim emulzijama (majonez, salatni prelivi, namazi) kao zamena za masne materije da bi obezbedili viskozitet, poželjne senzorne osobine i smanjenje energetske vrednosti proizvoda.<br />Viskozitet razblaženih rastora maltodekstrina različitog dekstroznog ekvivalenta i botaničkog porekla meren je kapilarnim viskozimetrom i izračunate su vrednosti unutra&scaron;njeg viskoziteta za pojedine maltodekstrine. Vrednosti untra&scaron;njeg viskoziteta i molekulske mase pokoravaju se zavisnosti &Scaron;taudingerove jednačine, iako su molekuli maltodekstrina relativno kratki i ne spadaju u grupu polimera. Utvrđena je mogućnost odredivanja DE- vrednosti viskozimetrijskin putem i izvedene su jednačine za dva opsega DE (5-10 / 10-20).<br />Da bi se ispitalo pona&scaron;anje emulzija sa maltodekstrinima (emulgovanje) u procesnim uslovima, kao i osobine fmalnih proizvoda (tečljivost, mazivost) ispitivana je dinamika emulgovanja, veličina kapljica i reolo&scaron;ko pona&scaron;anje, tj. uticaj različitih faktora na disperzione karakteristike emulzija suncokretovog ulja u vodi stabilizovanih prehrambenim emulgatorom, sa dodatkom maltodekstrina u kontinualnoj fazi.<br />Utvrđeno je da osobine maltodekstina kao &scaron;to je stepen konverzije (DE-vrednost) tj. veličina molekula maltodekstrina, utiču na dispezione i reolo&scaron;ke osobine emulzija. Uticaj koncentracije ulja i maltodekstrina, kao i delimična zamena ulja maltodekstrinom, na osobine emulzija su takode ispitivane. Sa povećanjem koncentracije ulja, pri istoj koncentraciji maltodekstrina u kontinualnoj fazi, emulzije menjaju tip proticanja od pseudoplastičnog preko tiksotropnog do antitiksotrpnog. Atitiksotropija izazvana smicanjem rezultat je formiranja unutra&scaron;nje strukture emulzije usled povezivanja kapljica ulja preko molekula maltodekstrina kao i orijentacije i deformacije kapljica ulja i maltodekstrina.<br />Dodatkom maltodekstrina za pri istoj koncentraciju ulja i vremenu emulgovanja dobijene su se emulzije sitnijih kapi.<br />Emulzije sa niskom koncentracijom ulja (30%) sa maltodekstrinom u kontinualnoj fazi bile su nestabilne i pokazivale efekat isplivavanja na povr&scaron;inu (creaming), &scaron;to je posledica interakcija molekula maltodekstrina i molekula emulgatora Tween 80 u kontinualnoj fazi i na povr&scaron;ini kapi.</p> / <p>Abstract was processed by technology for Optical character recognition (OCR).</p><p>Maltodextrins, low converted products of starch hydrolysis (dextrose equivalent less than 20), have been subject of various investigations due to their wide application in food industry, cosmetics and pharmaceuticals. They are used in various low energy food emulsions (mayonnaise, salad dressing, spreads) as fat replacer to provide desirable viscosity, texture and sensory fat-like mouthfeel.<br />Viscosity of diluted maltodextrin solutions of different dextrose equivalent and botanical origin were determined by capillary visometer and intrinsic viscosity [q] of each tested maltodextrin was calculated. The values of [q] together with molecular mass M have shown applicability of Staudinger equation, regardless maltodextrin molecules are rather short. The possibility for the determination of DE-values of maltodextrins by viscometric method has been deduced and the equation was calculated for two ranges of DE (5-10/ 10-20).<br />In order to assess behavior of sunflower oil in water emulsions stabilized with food grade emulsifier with addition of maltodextrins in continuous phase in processing (emulsification), as well as end products in application (pouring, spreading) the emulsification dynamics, globule size changes and rheological behavior, as well as, the influence of different factors on dispersion characteristics of such emulsions were studied.<br />Dispersion and viscous properties of emulsions were influenced by certain specific maltodextrin characteristics such as degree of conversion (DE value) i.e. size of maltodextrin molecules. Influence of oil and maltodextrin concentration and partial substitution of oil with equivalent quantity of maltodextrin were investigated too. With increase of oil concentration at the same concentration of maltodextrin in continuous phase, emulsions undergo changes in flow type from shear-thinning to thixotropic and antithixotropic. Antithxotropy induced by shear, was result of formation of network due to two competing factors; linking of oil droplets through maltodextrin molecules as well as orientation of deformed oil droplets and maltodextrin molecules.<br />Addition of maltodextrin, at the same oil concentration and emulsification time, resulted in formation of emulsions with smaller oil droplets.<br />Emulsions with low oil concentration (30%) with maltodextrin in continuous phase were unstable, showing so called creaming effect. This was mainly due to interactions between maltodextrin and emulsifier Tween 80 molecules which took place in continuous phase and on droplet surfaces.</p>
372

Effect Of High Hydrostatic Pressure (hhp) And High Dynamic Pressure (hdp) On Stability And Rheological Properties Of Model Oil-in-water Emulsions

Bigikocin, Erman 01 September 2010 (has links) (PDF)
High pressure applications are alternatives to conventional methods in food processing. They provide interesting modifications in food structures which leads to new product formulations. The aim of this study is to identify the effects of two different treatments, high hydrostatic pressure (HHP) and high dynamic pressure (HDP) on stability and rheological properties of model oil-in-water emulsions. Microfluidization was selected among the HDP homogenization techniques. The performance of each process was analyzed in terms of rheological modifications and emulsion stability improvements compared to the coarse emulsions which were prepared with colloid mill homogenization. Stability of emulsions was determined comparatively by using an analytical photo-centrifuge device employing a novel analysis technology. Whey protein isolate (WPI) was used as an emulsifier in combination with a food polysaccharide as a stabilizer. The polysaccharides used were xanthan gum, guar gum and locust bean gum which are widely used stabilizing ingredients in food industry. The effective disruption of oil droplets and the degradation of polysaccharides by the shear forces under high pressure in HDP microfluidization yielded finer emulsions with lower viscosities. The finer emulsions obtained with this homogenization technique led to distinctive improvements in emulsion stability. On the other hand, the improvements in stability by HHP treatment were due to the thickening of the emulsions mainly induced by protein unfolding. The corresponding increases in viscosity were intensified in emulsion formulations with higher oil content. Apart from these, HHP treatment was found to be relatively more contributing to the enhancements in viscoelastic properties.
373

Caractérisation de Milieux diffusants en écoulement par transport incohérent de lumière polarisée

Dillet, Jérôme 19 January 2007 (has links) (PDF)
Dans le cadre de cette thèse, nous nous intéressons au problème général de la caractérisation des dispersions concentrées. Nous développons une technique optique de diffusion basée sur le transport incohérent de lumière polarisée. Nous proposons un dispositif expérimental permettant l'acquisition de la matrice Mueller (Matrice 4x4 2D) représentant l'ensemble des interactions entre la lumière et un milieu diffusant. Le dispositif est constitué d'une source laser focalisée à la surface de l'échantillon et d'une caméra CCD permettant l'acquisition des images rétrodiffusées. Des lames à cristaux liquides sont utilisées pour sélectionner rapidement différents états de polarisation en entrée (source) et en sortie (acquisition). Parallèlement nous construisions puis analysons une base de données de simulations de Monte Carlo basée sur la théorie de Mie. Par confrontation des données expérimentales et numériques nous déterminons la taille moyenne des particules en suspension indépendamment de leur concentration. Le principe de mesure est validé sur des émulsions d'huile dans de l'eau puis appliqué à une étude d'un mécanisme de coacervation. Avec l'hypothèse que les propriétés optiques sont connues, nous effectuons une mesure simultanée et in situ de la taille des particules et de leur concentration. Une seconde partie de la thèse utilisera le transport anisotrope de lumière pour l'étude de suspensions biréfringentes ou anisotropes (Argile, bâtonnets de verre, suspensions sanguines) sous écoulement cisaillé. Pour chaque système, nous déterminons un axe d'orientation ou de déformation et nous quantifions l'anisotropie du système. Nous montrons donc que le transport stationnaire incohérent de lumière polarisée en milieu turbide est un outil permettant de caractériser des dispersions de nature variée en terme de taille, de concentration et d'orientation moyenne des objets dispersés sous écoulement.
374

Application of the HLD and NAC Models to the Formation and Stability of Emulsions

Kiran, Sumit K. 10 January 2014 (has links)
This thesis explored how asphaltene and naphthenic amphiphile species influence the formation (morphology and size) and stability of heavy crude oil (bitumen) emulsions. It was experimentally shown that asphaltenes produce water-in-oil emulsions. Naphthenic amphiphiles on the other hand flip the emulsion morphology to oil-in-water. It was further demonstrated that the size and stability of these emulsions is influenced by physicochemical effects such as the pH, solvent-bitumen-water ratios, solvent aromaticity, and temperature. In view of these findings, the hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC) models were looked at as potential means for predicting the formation and stability of emulsions. Owing to the complexity of bitumen emulsions, however, the HLD and NAC models were instead tested against well-defined sodium dihexyl sulfosuccinate-toluene-water emulsions. The morphologies of these emulsions were predicted as a function of the formulation salinity whereas corresponding droplet sizes were predicted as a function of the continuous phase density and interfacial tension (γow). Emulsion stability trends were in turn predicted using a collision-coalescence-separation assumption. From this assumption, emulsion stability was expressed as a function of the emulsion droplet collision frequency and activation energy. The key parameters of the highly scrutinized activation energy term included the γow, interfacial rigidity, and critical film thickness. In applying the same modeling approach to the stability of other emulsions already published in the literature, it was found that the rigidity of adsorbed multilayer/liquid crystal films cannot yet be fully accounted for. This shortcoming was the reason for which only minimum stability times were reported for bitumen emulsions.
375

Application of the HLD and NAC Models to the Formation and Stability of Emulsions

Kiran, Sumit K. 10 January 2014 (has links)
This thesis explored how asphaltene and naphthenic amphiphile species influence the formation (morphology and size) and stability of heavy crude oil (bitumen) emulsions. It was experimentally shown that asphaltenes produce water-in-oil emulsions. Naphthenic amphiphiles on the other hand flip the emulsion morphology to oil-in-water. It was further demonstrated that the size and stability of these emulsions is influenced by physicochemical effects such as the pH, solvent-bitumen-water ratios, solvent aromaticity, and temperature. In view of these findings, the hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC) models were looked at as potential means for predicting the formation and stability of emulsions. Owing to the complexity of bitumen emulsions, however, the HLD and NAC models were instead tested against well-defined sodium dihexyl sulfosuccinate-toluene-water emulsions. The morphologies of these emulsions were predicted as a function of the formulation salinity whereas corresponding droplet sizes were predicted as a function of the continuous phase density and interfacial tension (γow). Emulsion stability trends were in turn predicted using a collision-coalescence-separation assumption. From this assumption, emulsion stability was expressed as a function of the emulsion droplet collision frequency and activation energy. The key parameters of the highly scrutinized activation energy term included the γow, interfacial rigidity, and critical film thickness. In applying the same modeling approach to the stability of other emulsions already published in the literature, it was found that the rigidity of adsorbed multilayer/liquid crystal films cannot yet be fully accounted for. This shortcoming was the reason for which only minimum stability times were reported for bitumen emulsions.
376

Mid-infrared sensors for hydrocarbon analysis in extreme environments

Luzinova, Yuliya 29 June 2010 (has links)
A number of MIR sensing platforms and methods were developed in this research work demonstrating potential applicability of MIR spectroscopy for studying hydrocarbon systems in extreme environments. First of all, the quantitative determination of the diamondoid compound adamantane in organic media utilizing IR-ATR spectroscopy at waveguide surfaces was established. The developed analytical strategy further enabled the successful detection of adamantane in real world crude oil samples. These reported efforts provide a promising outlook for detection and monitoring of diamondoid constituents in naturally occurring crudes and petroleum samples. IR-ATR spectroscopy was further utilized for evaluating and characterizing distribution, variations, and origin of carbonate minerals within sediment formations surrounding a hydrocarbon seep site - MC 118 in the Gulf of Mexico. An analytical model for direct detection of 13C-depleted authigenic carbonates associated with cold seep ecosystems was constructed. Potential applicability of IR-ATR spectroscopy as direct on-ship - and in future in situ - analytical tool for characterizing hydrocarbon seep sites was demonstrated. MIR evanescent field absorption spectroscopy was also utilized to expand the understanding on the role of surfactants during gas hydrate formation at surfaces. This experimental method allowed detailed spectroscopic observations of detergent-related surface processes during SDS mediated gas hydrate formation. The obtained IR data enabled proposing a mechanism by which SDS decreases the induction time for hydrate nucleation, and promotes hydrate formation. Potential of MIR fiberoptic evanescent field spectroscopy for studying surface effects during gas hydrate nucleation and growth was demonstrated. Next, quantifying trace amounts of water content in hexane using MIR evanescent field absorption spectroscopy is presented. The improvement in sensitivity and of limit of detection was obtained by coating an optical fiber with layer of a hydrophilic polymer. The application of the polymer layer has enabled the on-line MIR detection of water in hexane at low ppm levels. These results indicate that the MIR evanescent filed spectroscopy method shows potential for in-situ detection and monitoring of water in industrial oils and petroleum products. Finally, quantification of trace amounts of oil content in water using MIR evanescent field absorption spectroscopy is reported. Unmodified and modified with grafted hydrophobic polymer layer silver halide optical fibers were employed for the measurements. The surface modification of the fiber has enabled the on-line MIR analysis of crude oil in water at the low ppb level. Potential application of MIR fiber-optic evanescent field spectroscopy using polymer modified waveguides toward in-situ low level detection of crude oil in open waters was demonstrated.
377

Mesure d’un écoulement diphasique liquide/liquide par holographie numérique en ligne : application à la caractérisation des émulsions en colonne pulsée / In line digital holography measurement for liquid-liquid flow : application to the characterization of emulsions produced in pulsed column

Lamadie, Fabrice 24 May 2013 (has links)
De nombreux procédés de la recherche et de l'industrie utilisent l'extraction liquide-liquide, technique qui permet la séparation sélective de produits au sein d'un mélange. À cet effet, deux liquides non miscibles sont mis en contact : une phase aqueuse et une phase organique, l'une contenant généralement une molécule extractante capable de transférer les éléments désirés à l'autre. Le transfert se produit à la surface de contact entre les deux phases. Après le transfert, les deux phases sont séparées par décantation. Dans la pratique, ces opérations sont effectuées dans des appareils industriels. Pour optimiser et comprendre le fonctionnement de ces dispositifs, il est important de déterminer les caractéristiques fondamentales de l'émulsion. Il s'agit notamment des paramètres liés à la vitesse des écoulements ainsi que ceux liés au mélange des fluides comme l'aire interfaciale, le taux de rétention, ou la distribution en taille de la population de gouttes. Plusieurs techniques d'imagerie peuvent être utilisées pour les mesurer. L'une d'elles, l'holographie numérique, est bien connue pour permettre la reconstruction complète en 3D d'un écoulement à partir d'une seule acquisition. Ce travail de thèse traite d'une application de l'holographie numérique en ligne directement sur des gouttes en mouvement dans une phase liquide continue. La taille des gouttes a imposé l'exploration d'un régime de diffraction peu étudié à ce jour. Dans ce domaine, le modèle du disque opaque classiquement employé n'est pas valide et un meilleur accord est obtenu avec un modèle mixte lui associant une lentille mince. La focalisation des hologrammes est réalisée via une méthode dédiée et automatique qui a été établie à partir d'une étude complète de la littérature. Dans un deuxième temps, afin de mesurer des rétentions plus élevées, elle est complétée par une approche inverse permettant de corriger les mauvais positionnements et de restituer les gouttes non détectées. Ce traitement a été appliqué à des résultats expérimentaux, sur un dispositif de référence produisant des gouttes calibrées, et comparé à des mesures indépendantes. Ces essais ont validé la pertinence de l'holographie pour la caractérisation des émulsions. / Several processes used in research and industry are based on liquid-liquid extraction, a method designed for selective separation of products in a mixture. In liquid-liquid extraction, two immiscible liquids are contacted: an aqueous phase and an organic phase, one of which generally contains an extractant molecule capable of transferring the desired elements to the other phase. The transfer occurs at the contact surface between the two phases. After transfer, both phases are separated by settling. In practice, these operations are performed in industrial apparatus. In order to optimize the operation of these devices, it's important to determine the fundamental characteristics of the emulsion. These include parameters related to the fluid flow velocity as well as parameters related to fluid mixing such as the interfacial area, hold-up, and size distribution of the droplets population. Numerous imaging techniques can be used to measure these parameters. One of them, digital holography, is well-known for allowing complete reconstruction of information about a 3D flow in a single shot. This PhD work deals with a direct application of digital in line holography to droplets rising in a continuous liquid phase. The droplet size imposes a regime of intermediate-field diffraction hardly explored to date. Acquired diffraction patterns show that the usual dark disk model is not valid and that good agreement is obtained with a mixed model coupling thin lens with opaque disk. Hologram focusing is nevertheless performed with a dedicated automated method. A literature review has been conducted to identify the sharpest autofocus function for our application. In a second step, in order to measure high retention rates, an inverse problem approach is applied on all the outliers and missing droplets. This hologram restitution treatment has been applied to experimental results with a comparison to independent measurements. The main results obtained with calibrated droplets are presented detailing the test device and instrumentation. They have validated the relevance of holography for the characterization of emulsions.
378

Hierarchically Porous Silica Materials for the Encapsulation of Molecules of Interest / Matériaux silicatés à porosité hiérarchisée pour l'encapsulation de molécules d'intérêts

Riachy, Philippe 14 March 2016 (has links)
Ce travail porte sur la préparation de matériaux silicatés à porosité hiérarchisée pour l'encapsulation de molécules d'intérêt dans le domaine de la pharmacie et en tant que biocatalyseur. Afin d’atteindre cet objectif, les nano-émulsions sont choisies comme empreinte pour créer les macropores du matériau en raison de la taille homogène et réduite des gouttelettes de l’émulsion (inférieure à 100 nm). Pour cela le système Remcopal 4/décane/eau est investi en déterminant les conditions les plus optimales de formation de nano-émulsion, via les méthodes d'inversion de phases. L’ajout de micelles aux nano-émulsions ne déstabilise pas les émulsions et permet la formation d’un réseau de mésopores organisés selon une symétrie hexagonale. Les matériaux hybrides issus des matériaux poreux contenant encore la phase organique sont dopés par le ketoprofène en vue d’étudier la libération de ce dernier. Celle-ci se révèle sensible au pH. De plus, cette étude de la libération du kétoprofène à partir du matériau méso-macroporeux indique qu'elle est assistée par les micelles qui sont solubilisées dans la solution réceptrice. Le deuxième objectif de ce travail est d'utiliser ces matériaux poreux en tant que biocatalyseur pour la synthèse de biodiesel à partir d'huile de colza. Pour cette application, il est nécessaire que les matériaux résistent à l’immersion dans des milieux aqueux. L’étude de la stabilité hydrothermale a montré que le matériau calciné présente la meilleure stabilité dans l’eau bouillante. Par ailleurs, le matériau peut résister jusqu’à 550°C, la structure ne subissant que des dégradations mineures. Nous avons également utilisé un matériau silicaté à double mésoporosité préparé à partir de micelles fluorées et hydrogénées coexistant dans une même solution. L'évaluation thermique et hydrothermale indique que ces matériaux présentent deux cinétiques de déstructuration qui correspondent à chacune des deux matrices ayant deux tailles de pores différents. L’immobilisation de la lipase Mml est étudiée sur le matériau méso-macroporeux calciné et sur le matériau à double mésoporosité. Les isothermes d'adsorption ont permis de mettre en évidence que le matériau à double mésoporosité peut encapsuler plus d’enzymes que son homologue méso-macroporeux. L’activité enzymatique, au regard des réactions de transestérification, est de façon inverse plus importante avec le matériau méso-macroporeux calciné / This work concerns the preparation of silica materials with hierarchical porosity for the encapsulation of molecules of interest in the field of drug delivery and as biocatalysts. In order to reach this goal, the nano-emulsions were chosen as templates for the macropores of the material because of the homogeneous and small size of the emulsion droplets (less than 100 nm). The system Remcopal 4/decane/water was investigated and the optimal conditions for which nano-emulsion is formed via the phase inversion methods were determined. Adding micelles to the nano-emulsions does not affect its stability and can form a network of mesopores organized with a hexagonal symmetry. Hybrid materials which are hierarchically porous materials where the organic phase is still present, were doped with ketoprofen to study its release, which proved to be pH sensitive. Moreover, the study of the release of ketoprofen from the meso-macroporous material indicates that it is assisted by the micelles which are solubilized in the release medium. The second objective of this work was to use these porous materials as a biocatalyst for biodiesel synthesis from colza oil. For this application it was necessary that the materials are resistant to immersion in aqueous media. The study of the hydrothermal stability shows that the calcined material has the best stability in boiling water. Moreover, the material can withstand up to 550 ° C, the structure undergoes only minor damages. We also used a dual-mesoporous silica material prepared from hydrogenated and fluorinated micelles coexisting in the same solution. Thermal and hydrothermal evaluation indicates that these materials have two different decay kinetics corresponding to each of the two matrices having different pore sizes. The immobilization of lipase Mml was studied on the meso-macroporous calcined material and the dual-mesoporous material. The adsorption isotherms were used to demonstrate that the dual-mesoporous material can encapsulate more enzymes than its meso-macroporous counterpart. On the other hand, the enzyme activity, evaluated by the transesterification reactions, is more important for the calcined meso-macroporous material
379

Ionic Liquid/Water/Particle Systems: Fundamentals Through Experiment, Application and Simulation

January 2016 (has links)
abstract: Ionic liquids (ILs), or low-temperature liquid salts, are a class of materials with unique and useful properties. Made up entirely of ions, ILs are remarkably tunable and diverse as cations and anions can be mixed and matched to yield desired properties. Because of this, IL/water systems range widely—from homogeneous mixtures to multiphasic systems featuring ionic liquid/liquid interfaces. Even more diversity is added when particles are introduced to these systems, as hard particles or soft-matter microgels interact with both ILs and water in complex ways. This work examines both miscible ionic liquid/water mixture and two-phase, immiscible ionic liquid/water systems. Extensive molecular dynamics (MD) simulations are utilized in conjunction with physical measurements to inform theoretical understanding of the nature of these systems, and this theoretical understanding is related to practical applications—in particular, the development of a low-temperature liquid electrolyte for use in molecular electronic transducer (MET) seismometers, and particle self-assembly and transport at ionic liquid/liquid interfaces such as those in Pickering emulsions. The homogenous mixture of 1-butyl-3-methylimidazolium iodide and water is examined extensively through MD as well as physical characterization of properties. Molecular ordering within the liquid mixture is related to macroscopic properties. These mixtures are then used as the basis of an electrolyte with unusual characteristics, specifically a wide liquid temperature range with an extremely low lower bound combined with relatively low viscosity allowing excellent performance in the MET sensor. Electrolyte performance is further improved by the addition of fullerene nanoparticles, which dramatically increase device sensitivity. The reasons behind this effect are explored by testing the effect of graphene surface size and through MD simulations of fullerene and a silica nanoparticle (for contrast) in [BMIM][I]/water mixtures. Immiscible ionic liquid/water systems are explored through MD studies of particles at IL/water interfaces. By increasing the concentration of hydrophobic nanoparticles at the IL/water interface, one study discovers the formation of a commingled IL/water/particle pseudo-phase, and relates this discovery to previously-observed unique behaviors of these interfaces, particularly spontaneous particle transport across the interface. The other study demonstrates that IL hydrophobicity can influence the deformation of thermo-responsive soft particles at the liquid/liquid interface. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2016
380

Avaliação de emulsificante baseado na borra de óleo de soja para fluidos de perfuração sintéticos.

LEAL, Caline Alves. 22 June 2018 (has links)
Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-22T00:02:26Z No. of bitstreams: 1 CALINE ALVES LEAL – DISSERTAÇÃO (UAEMa) 2015.pdf: 2311044 bytes, checksum: 88f266b137f954d280e66561ae118c64 (MD5) / Made available in DSpace on 2018-06-22T00:02:26Z (GMT). No. of bitstreams: 1 CALINE ALVES LEAL – DISSERTAÇÃO (UAEMa) 2015.pdf: 2311044 bytes, checksum: 88f266b137f954d280e66561ae118c64 (MD5) Previous issue date: 2018-06-21 / CNPq / Este trabalho visa avaliar o desempenho de um emulsificante baseado na borra de óleo de soja (EBO) para fluido de perfuração sintético a base de n-parafina. O estudo do emulsificante foi realizado em três etapas distintas: na primeira, a caracterização do emulsificante por meio dos ensaios de ATG, DTA e FTIR; na segunda, a avaliação do emulsificante de acordo com a norma EP-1EP-00028-A da Petrobras e, a terceira e última etapa, dedicada a avaliação do emulsificante em formulações da indústria, por meio das propriedades reológicas (viscosidade aparente (VA), viscosidade plástica (VP), limite de escoamento (LE) e força gel (FG)), a estabilidade elétrica (EE) e o volume de filtrado HPHT (VF). A partir dos resultados obtidos pode-se concluir que: o emulsificante obtido a partir da borra do óleo de soja (EBO) é formado a partir de ácidos graxos com ligações dos tipos C-H, C-O, C=O e C=C, com picos de intensidades e posições semelhantes ao óleo de soja puro, apresentando três etapas de decomposição térmica: a primeira referente a perda de material volátil, a segunda a matéria carbonosa e a terceira a decomposição térmica do EBO; a borra de óleo de soja pode ser utilizada como emulsificante primário para fluidos de perfuração sintético e, por fim, que o emulsificante EBO apresentou maior eficiência nas propriedades reológicas (VA, VP, LE e FG) e de filtração (VF) para fluidos sintéticos com razão óleo água 60/40. No entanto, quando se trata da EE os melhores resultados foram obtidos para fluidos com razão óleo água 70/30. / This study aimed to evaluate the performance of an emulsifier based on soybean oil sludge (EBO) in synthetic drilling fluid to n-paraffin base. The study of the emulsifier was conducted in three distinct stages: first, the characterization of the emulsifier through the TGA , DTA and FTIR tests; second, the evaluation of the emulsifier according to the standard EP-1EP-00028-Petrobras norm; and the third and last stage, the evaluation of the emulsifier according to the industry formulations which were evaluated by the rheological properties (apparent viscosities (AV), plastic viscosity (PV), yield limit (YL) and gel strength (GS)), the electrical stability (ES) and the filtrate volume HPHT (VF). From the results obtained it can be concluded that: the emulsifier obtained from soybean oil sludge (EBO) is formed from fatty acids with HC, C-O, C = O and C = C bond types, with peaks intensities and positions similar to pure soybean oil, with three-step thermal decomposition: The First Regarding Volatil loss material, the second carbonaceous matter ea Third thermal decomposition do EBO. Soybean oil sludge can be used as a primary emulsifier for synthetic drilling fluids and finally the EBO emulsifier with highest efficiency rheological properties (AV, PV, YL and GS) and filtering (FV) or synthetic fluids with water oil ratio 60/40. However, when it comes EE best results were obtained with a ratio of oil to water fluid 70/30.

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