Skin creams are one of Sky Resources key products, they are produced as an oil-in-water(O/W) emulsion. In order to form an emulsion the oil and water needs to be able to mixtogether, for that to happen the oil and water droplets have to be broken up into very smalldroplets (colloids). There is a certain quality difference between the products from the research and developmentdepartment and the production department. The skin creams have been made through a given recipe, which contains a number of chemicalformulas. Tests have been preformed and the results have been examined. The creams werefirst made in the research and development department’s laboratory and then that small scaleproduction was taken to big scale production in the production department. The results havebeen documented and the parameters that have been examined are speed, temperature and timeto see how they affect the viscosity of the creams. A factorial experiment with three factors has been made. The factors are the time the skincream is homogenized, at what speed the cream is homogenized and at what temperature thephases are when the homogenizing is started. That gives a total of 8 creams from thelaboratory level. The viscosity of the skin creams have been measured after 10 minutes, 24 hours, 48 hours and1 week to see how it is increasing with time and if it is increasing at all or perhaps decreasing.After 1 week the creams were also studied under a microscope to see how successful theemulsions were with different factors. The fourth cream was the only cream from the laboratory that had a successful emulsion andstabilized viscosity. So the factors that are brought from laboratory to production is highhomogenization time, high homogenization speed and low temperature. Two differenthomogenizers were tried in production. The factor that affects the viscosity the most seems to be the temperature. After these tests,there is still a difference between the products from the research and development departmentand the production department even with the lower temperatures on the oil and water phases.The second cream from production and cream 4 from the laboratory show the smallest qualitydifference. More tests need to be done in the production department with differenthomogenization speed and time with the lower temperature to establish the result. / Hudkrämer är en av Sky Resources viktigaste produkter, de produceras som en olja-i-vattenemulsion(O/W). För att bilda en emulsion måste oljan och vattnet kunna blandas och för attdet ska hända måste olje- och vattendropparna brytas upp i mycket små droppar (kolloider). Det finns en viss kvalitetsskillnad mellan produkterna från forsknings- ochutvecklingsavdelningen och produktionsavdelningen. Hudkrämerna har gjorts genom ett givet recept, som innehåller ett antal kemiska ingredienser. Tester har utformats och resultaten har undersökts. Krämerna gjordes först i forsknings- ochutvecklingsavdelningen laboratorium och sedan togs den småskaliga produktionen tillstorskalig produktion i produktionsavdelningen. Resultaten har dokumenterats ochparametrarna som har undersökts är hastighet, temperatur och tid för att se hur de påverkarviskositeten hos krämerna. Ett faktorförsök med tre faktorer har gjorts. Faktorerna som använts är den tid hudkrämenhomogeniseras, i vilken hastighet krämen homogeniseras och vid vilken temperatur faserna ärnär homogeniseringen startas. Det ger totalt 8 krämer från laboratorienivån. Viskositeten hos hudkrämerna mättes efter 10 minuter, 24 timmar, 48 timmar och 1 vecka föratt se hur den ändras med tiden. Efter 1 vecka studerades också krämerna under ett mikroskopför att se hur lyckad emulsionerna var med olika faktorer. Den fjärde krämen var den enda krämen från laboratoriet som hade en lyckad emulsion och enstabil viskositet. Så de faktorer som tas från laboratorium till produktion är höghomogeniseringstid, hög homogeniseringshastighet och låg temperatur. Försök gjordes i tvåhomogenisatorer i produktionen. Den faktor som påverkar viskositeten mest är temperaturen. Efter dessa tester finns det dockfortfarande skillnader mellan produkterna från forsknings- och utvecklingsavdelningen ochproduktionsavdelningen, även med de lägre temperaturerna på olje- och vattenfaserna. Denandra krämen från produktion och kräm 4 från laboratoriet visar den minstakvalitetsskillnaden. Fler test måste göras i produktionsavdelningen med olikahomogeniseringshastigheter och tider med den lägre temperaturen för att fastställa resultatet.

The mixing of polymers and nanoparticles makes it possible to give advantageous macroscopic material performance by tailoring the microstructure of composites. In this thesis, five combinations of nano inclusion and polymer matrix have been investigated. The first type of composites is titanium dioxide/ polyaniline combination. The effects of 4 different doping-acids on the microstructure, morphology, thermal stability and thermoelectric properties were discussed, showing that the sample with HCl and sulfosalicylic dual acids gave a better thermoelectric property. The second combination is titanium dioxide/polystyrene composite. Avrami equation was used to investigate the crystallization process. The best fit of the mass derivative dependence on temperature has been obtained using the double Gaussian dependence. The third combination is titanium dioxide/polyaniline/ polystyrene. In the titanium dioxide/polyaniline/ polystyrene ternary system, polystyrene provides the mechanical strength supporting the whole structure; TiO2 nanoparticles are the thermoelectric component; Polyaniline (PANI) gives the additional boost to the electrical conductivity. We also did some investigations on Polyethylene odide-TiO2 composite. The cubic anatase TiO2 with an average size of 13nm was mixed with Polyethylene-oxide using Nano Debee equipment from BEE international; Single wall carbon nanotubes were introduced into the vinyl acetate-ethylene copolymer (VAE) to form a connecting network, using high pressure homogenizer (HPH). The processing time has been reduced to 1/60 of sonication for HPH to give better sample quality. Theoretical percolation was derived according to the excluded volume theory in the expression of the threshold as a function of aspect ratio.

La modélisation des phénomènes de brisure de gouttes lors d’opérations d’émulsification par bilan de population (PBE), a pour but de suivre l’évolution de la distribution des tailles de gouttes (DSD). Ceci a fait l’objet d’un grand nombre d’études au cours des deux dernières décennies. Une approche multiéchelle, couplant la modélisation des phénomènes de brisure à l’échelle d’une goutte avec les phénomènes agissant à l’échelle du champ d’écoulement est nécessaire pour simuler correctement les procédés d’ émulsification dans des géométries complexes tels que des mélangeurs statiques ou des homogénéisateurs à haute pression. Une telle approche est présentée dans cette thèse par l’emploi d’un couplage entre PBE et mécanique des fluides numériques (CFD). Trois types de procédés d’émulsification huile dans l’eau ont été étudiés : une cuve agitée de deux litres,équipée avec d’une hélice Mixel-TT générant un écoulement axial de la phase continue, pour deux systèmes modèles : Di-Stereate d’éthylène Glycol (EGDS) dans l’eau d’une part, huiles silicones de différentes viscosités d’autre part. Un montage expérimental sur mesure a été conçu pour l’émulsification d’huiles silicones dans eau basé sur l’emploi de mélangeurs statiques de type SMX+. Des expériences d’émulsification des huiles végétales de qualité alimentaire dans un homogénéisateur à haute pression (HPH) ont été réalisées dans le laboratoires d’UNILEVER R&D à Vlaardingen, Pays-Bas. Deux techniques d’analyse granulométrique in-situ ont été comparées aux résultats obtenus par la technique ex situ de diffraction laser : une sonde vidéo avec traitement automatisé d’images (basé sur la transforméecirculaire de Hough), et une sonde de réflectance laser « Focused Beam Reflectance Measurement »(FBRM), qui mesure la distribution de cordes (CLD). Les sondes ont été introduites dans la cuve agitée et une cellule de mesure a été conçue spécialement pour implanter en-ligne la sonde video et mesurer ainsi la DSD en amont et en aval des mélangeurs statiques. La technique FBRM n’a pas permis de détecter les plus grosses gouttes et la transformation de la CLD en DSD donnait une sous-estimation de la taille des gouttes. Cette méthode n’est par conséquent pas adaptée à l’analyse granulométrique des gouttes transparentes, telles que les huiles silicones. Par contre, la détection des gouttes sur les images prises par la sonde vidéo, permet de produire des mesures fiables de la DSD pour des concentration dephase dispersée faible (≤ 10 %). L’algorithme de détection a été amélioré pour être capable de mesurerla DSD des émulsions avec 10 – 20 % de phase dispersée. La partie modélisation de cette thèse se compose premièrement de l’élaboration d’un nouveau modèlede brisure qui est capables de représenter l’effet de la viscosité de la phase dispersée. Ce modèle est une amélioration du modèle phénoménologique proposé par Luo & Svendsen (1996). Deuxièmement le couplage entre des PBE discrétisées par volumes finis avec la CFD en régime turbulent a été réalisé, dans le code open-source OpenFOAM (OpenCFD). / The modelling of breakage phenomena with the goal to simulate the evolution of drop size distributions(DSDs) in turbulent emulsification by Population Balance Equation (PBE) modeling has been an activearea of research over the last decade. A multi-scale approach, combining the breakage phenomena on the droplet scale with the larger scale flow-field characteristics is necessary to accurately simulate emulsification in complex geometries such as High-Pressure homogenizers and static mixers. Emulsifications were performed for Ethylene Glycol Di-Stearate-in-water and Silicone oil-in-water systemsin a stirred tank reactor, using an axial-flow Mixel-TT impeller, as well as SMX+ (Sulzer) static mixers for the silicone oil system at the LAGEP, Lyon, France. Emulsifications of food-grade vegetableoils in a High-pressure Homogenizer were performed at UNILEVER R&D, Vlaardingen, Netherlands. Two in-situ DSD measurement techniques were compared to results obtained form laser diffraction measurements of samples. Focused Beam Reflectance Measurement (FBRM), which generates achord length distribution was found give an under-prediction of the DSD and failed to detect the largerdroplets of the transparent silicone oils. This technique, while providing a continuous, in situ measurement of the DSD is not reliable for measuring transparent droplets. An in situ video probe with off-line droplet detection via Hough transform, developed at LAGEP, was found to give reliable and traceable DSD measurements for dilute emulsions. The image detection algorithm was improved to be capable of measuring droplets in emulsions with 10 – 20 % dispersed phase hold-up fraction.The modelling part of this thesis consists of the development of a framework for the coupling of PBEand CFD modelling, as well as a significant improvement to the well-known Luo & Svendsen (1996)breakage model. Different breakage models were compared for their applicability to emulsification ofEthylene Glycol di-Stereate (EGDS) and silicone oil in water emulsions in a 2-L stirred tank reactor. This analysis revealed the need for a phenomenological breakage model which does not rely on system dependent parameters and is able to accurately take the dispersed phase viscosity effects into account.Such a model was proposed, based on the Han et al. (2011) to the Luo & Svendsen (1996) framework. A dispersed phase viscosity term was added to the surface energy opposing breakage. This was validated by experimental data from emulsification of silicone oils with varying viscosities (20, 50, 100, 350 mPa.s). The new model was found to provide better predictions than the Alopaeus et al. (2002) and Vankova etal. ( 2007) breakage models, without the need for empirically determined parameters. The one-way coupling of CFD and PBE modelling was implemented in the open-source finite volumes software package OpenFOAM. This was applied to emulsification of vegetable oils with varying viscosities(25, 50, 100 mPa.s) in a Niro-soave bench-scale HPH. The new model was found to deliver good predictions for the drop size distribution after three consecutive passes through the HPH valve at the three different viscosities and varying pressure drops (200, 400, 600 bar).