The diploma thesis deals with the influence of technological parameters on the emulsion copolymerization of methyl methacrylate with n butyl acrylate. The theoretical part contains knowledge in the field of influences of proces tempereture, concentration of initiator, concentration of emulsifier, stirring rate and dose rate on emulsion polymerization. In the experimental part was observed effect of the concentration of the ionic emulsifier, nonionic emulsifier, furthemore was observed effect of stirring speed and the concentration of initiator K2S2O8 on conversion of copolymerization. During all copolymerizations, conversions was determinated via solids content evaluation. By dynamic light scattering was determinated and presented polymer particle size of the prepared emulsions. Stability of emuldions was observed via effect of different ionic strenght and yield of freeze thaw cycles coalescence. Based on experimental results were proposed conditions of polyacrylic lattex preparation.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第12820号 / 論農博第2793号 / 新制||農||1025(附属図書館) / 学位論文||H26||N4815(農学部図書室) / 31307 / 京都大学農学研究科農学専攻 / (主査)教授 松村 康生, 教授 裏出 令子, 教授 安達 修二 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Part A The use of nonionic associative thickeners was proposed for personal care applications. Various limitations of current rheology modifiers used in personal care were discussed. Nonionic associative polymers were examined as both thickeners and emulsifiers. The structure/property relationship for nonionic polymers and their ability to thicken and emulsify were fully examined. Results showed an increase in thickening efficiency for nonionic associative polymers with higher log(P) (partition coefficient) values. This was due to the formation of smaller aggregates and increased bridging between aggregates. The connection between oil polarity, log(P) of the associative polymer, and emulsion stability showed no relationship however; as the log(P) value of the polymer decreased, emulsion stability increased. The effects of nonionic associative polymer molecular weight and thickening efficiency proved to be positive; as molecular weight increased, thickening efficiency increased. Specific interactions between nonionic associative thickeners and common ingredients in personal care products were also explored. The interaction between nonionic associative thickeners and surfactants proved to be dependent on surfactant type as well as hydrophobe shape and size on the associative thickener. There appeared to a clear effect of salt on the thickening and emulsifying capabilities of the nonionic associative polymers but the exact interaction was not yet determined. Part B Superoxide dismutation (SOD) chemistry pertaining to manganese enzymes was explored. A series of manganese SOD mimetic enzymes were synthesized and their SOD activity was examined. The McCord-Fridovich Assay showed mimetic enzymes containing secondary amine bonds and electron difficiency around bonding sites had higher SOD activity. Click chemistry was used for the synthesis of a 1,4-triazole containing tridentate ligand. The ideal reaction conditions chosen for the click reaction was a solvent blend of 1:1 dichloromethane and water with copper sulfate and sodium ascorbate as a catalyst. The tridentate ligand was grafted onto azido-functionalized polystyrene. Infrared spectroscopy was used to confirm the completion of the click reaction. The azide peak at 2100 cm-1 was removed after the click reaction was performed on the azido-functionalized polystyrene.

O objetivo do trabalho foi sintetizar e caracterizar nanopartículas de poliestireno e polimetacrilato de metila com morfologia núcleo-casca obtidas através da polimerização em emulsão sem emulsificante em dois estágios e através da fotopolimerização. Nos experimentos avaliou-se a influência de diferentes condições operacionais baseadas em fatores cinéticos sobre os dois estágios da polimerização. As condições avaliadas para o primeiro estágio de preparação de núcleos foram: a temperatura do processo, a concentração de iniciador e de monômero, e o efeito de agentes modificadores de superfície (sal, co-monômero e reticulante). Para o segundo estágio de formação da casca as condições avaliadas foram: a concentração e o regime de alimentação de monômero. Os resultados experimentais mostraram que uma relação de co-monômero e reticulante é a melhor alternativa para preparar núcleos estáveis e de diâmetros pequenos. Assim, o revestimento uniforme dos núcleos é obtido no segundo estágio e com isso a morfologia núcleo-casca em equilíbrio é alcançada. Dois sistemas experimentais (reator convencional e reator fotoquímico) foram propostos e avaliados na sua eficiência para obter partículas com este tipo de morfologia no segundo estágio (formação do revestimento). As diversas técnicas de caracterização indicaram a formação de morfologia núcleo-casca na maioria dos casos estudados para os dois sistemas propostos. Por sua vez, as técnicas espectroscópicas (NIR e Raman) permitiram o monitoramento do processo em tempo real e a elaboração de modelos de calibração que correlacionaram o crescimento do tamanho da partícula núcleo. Da mesma forma, os fatores termodinâmicos foram estudados para predizer a morfologia final esperada nos sistemas. Os resultados, experimental e predito são comparados e discutidos em termos de aspectos chave envolvidos no controle da morfologia da partícula. / This work aimed at studying the synthesis and characterization of core-shell nanoparticles of polystyrene and polymethylmethacrylate obtained in a two-stage emulsifier-free emulsion polymerization and photopolymerization. The influence of different operational conditions based on kinetic factors was experimentally evaluated. In the first stage (seed preparation) the process temperature, initiator and monomer concentrations and the effect of surface-modifier agents (acids, salts, co-monomers and crosslinker) were investigated; similarly in the second stage, the concentration and feeding regime of monomer were evaluated with respect to the shell formation. Experimental results showed that both, crosslinker and co-monomer are the best alternative to achieve a stable seed with small diameter; hence, with this core, uniform coating is obtained in the second stage and core-shell morphology is reached. In order to evaluate the efficiency of the preparation of core-shell particles, two experimental systems (conventional and photochemical reactor) were studied. Different characterization techniques indicated that in most of the cases studied particles with the desired core-shell morphology were formed. The use of spectroscopic techniques NIR and Raman were tested for the real-time monitoring of the process using adequate calibration models developed to correlate the average size of the growing core particle with the spectra. In the same way, thermodynamic factors were used to predict the expected final morphology of the particles. Experimental and predicted results were compared and discussed in terms of the key aspects involved in the control of the particle morphology.

O objetivo do trabalho foi sintetizar e caracterizar nanopartículas de poliestireno e polimetacrilato de metila com morfologia núcleo-casca obtidas através da polimerização em emulsão sem emulsificante em dois estágios e através da fotopolimerização. Nos experimentos avaliou-se a influência de diferentes condições operacionais baseadas em fatores cinéticos sobre os dois estágios da polimerização. As condições avaliadas para o primeiro estágio de preparação de núcleos foram: a temperatura do processo, a concentração de iniciador e de monômero, e o efeito de agentes modificadores de superfície (sal, co-monômero e reticulante). Para o segundo estágio de formação da casca as condições avaliadas foram: a concentração e o regime de alimentação de monômero. Os resultados experimentais mostraram que uma relação de co-monômero e reticulante é a melhor alternativa para preparar núcleos estáveis e de diâmetros pequenos. Assim, o revestimento uniforme dos núcleos é obtido no segundo estágio e com isso a morfologia núcleo-casca em equilíbrio é alcançada. Dois sistemas experimentais (reator convencional e reator fotoquímico) foram propostos e avaliados na sua eficiência para obter partículas com este tipo de morfologia no segundo estágio (formação do revestimento). As diversas técnicas de caracterização indicaram a formação de morfologia núcleo-casca na maioria dos casos estudados para os dois sistemas propostos. Por sua vez, as técnicas espectroscópicas (NIR e Raman) permitiram o monitoramento do processo em tempo real e a elaboração de modelos de calibração que correlacionaram o crescimento do tamanho da partícula núcleo. Da mesma forma, os fatores termodinâmicos foram estudados para predizer a morfologia final esperada nos sistemas. Os resultados, experimental e predito são comparados e discutidos em termos de aspectos chave envolvidos no controle da morfologia da partícula. / This work aimed at studying the synthesis and characterization of core-shell nanoparticles of polystyrene and polymethylmethacrylate obtained in a two-stage emulsifier-free emulsion polymerization and photopolymerization. The influence of different operational conditions based on kinetic factors was experimentally evaluated. In the first stage (seed preparation) the process temperature, initiator and monomer concentrations and the effect of surface-modifier agents (acids, salts, co-monomers and crosslinker) were investigated; similarly in the second stage, the concentration and feeding regime of monomer were evaluated with respect to the shell formation. Experimental results showed that both, crosslinker and co-monomer are the best alternative to achieve a stable seed with small diameter; hence, with this core, uniform coating is obtained in the second stage and core-shell morphology is reached. In order to evaluate the efficiency of the preparation of core-shell particles, two experimental systems (conventional and photochemical reactor) were studied. Different characterization techniques indicated that in most of the cases studied particles with the desired core-shell morphology were formed. The use of spectroscopic techniques NIR and Raman were tested for the real-time monitoring of the process using adequate calibration models developed to correlate the average size of the growing core particle with the spectra. In the same way, thermodynamic factors were used to predict the expected final morphology of the particles. Experimental and predicted results were compared and discussed in terms of the key aspects involved in the control of the particle morphology.

<p>Seme tikve (Cucurbita pepo) obiluje kako uljem tako i proteinima. Nakon izdvajanja ulja, proteini se koncentri&scaron;u u uljanoj pogači, sekundarnom proizvodu procesa proizvodnje ulja, gde njihov sadrţaj dostiţe do 65%. Proteini semena tikve su primamljiv sastojak za prehrambenu, farmaceutsku i kozmetičku industriju zbog svoje farmakolo&scaron;ke aktivnosti i visoke biolo&scaron;ke vrednosti. Pored toga, budući da su mnogi proizvodi ovih industrija po svojoj koloidnoj prirodi emulzije, proteini semena tikve bi se u njima mogli naći i kao prirodne povr&scaron;inski aktivne materije. Međutim, koloidna funkcionalnost proteina semena tikve se jo&scaron; uvek potcenjuje zbog globularne strukture za koju se vezuju slabija funkcionalna svojstva u odnosu na proteine sa fleksibilnijom strukturom. Prema tome, cilj ove disertacije je ispitivanje funkcionalnih osobina proteinskog izolata semena tikve, pre svega njegovih adsorpcionih i emulgujućih svojstava, kao i ispitivanje uticaja promene proteinske strukture putem enzimske hidrolize na ispitivana svojstva.<br />Pripremljeni su izolat proteina semena tikve (IPST) i dva enzimska hidrolizata, H1 i H2. IPST, H1 i H2 su okarakterisani određivanjem sadržaja vlage, proteina i pepela, zatim, određivanjem prinosa, molekulske mase i zeta potencijala. Ispitan je uticaj koncentracije proteina/peptida (0,0001&ndash;1 g/100 cm³), pH (3&ndash;8) i jonske jačine (0&ndash;1 mol/dm³ NaCl) na rastvorljivost i adsorpciona svojstva: dinamički međupovr&scaron;inski pritisak (ulje/voda), statički povr&scaron;inski (vazduh/voda) i međupovr&scaron;inski (ulje/voda) pritisak, kinetiku adsorpcije i dilatacionu reologiju proteinskih adsorpcionih filmova. Nakon toga, ispitan je i uticaj pomenutih parametara na emulziona svojstva IPST, H1 i H2. Emulgujuća svojstva IPST, H1 i H2 su okarakterisana na osnovu prosečnog prečnika kapljica emulzija, raspodele veličina kapljica i stabilnosti emulzija.<br />Utvrđeno je da je prinos IPST veći od prinosa oba hidrolizata za oko 65 %. IPST ima najniţu rastvorljivost na pH=5, &scaron;to ujedno predstavlja i njegovu izoelektričnu tačku. Enzimskom hidrolizom IPST značajno se povećava rastvorljivost, posebno na pI=5. Povećanje jonske jačine je izazvalo salting&ndash;in ili salting&ndash;out efekat rastvorljivosti kod svih uzoraka u zavisnosti od pH. IPST, H1 i H2 poseduju povr&scaron;insku aktivnost pri čemu je povr&scaron;inski/međupovr&scaron;inski pritisak H1 i H2 manje zavistan od promene pH i jonske jačine u poređenju sa povr&scaron;inskim/međupovr&scaron;inskim pritiskom IPST. Adsorpcijom na granicu faza IPST i oba hidrolizata obrazuju adsorpcione filmove sa dominantnom elastičnom komponentom. Emulgujuća svojstva IPST, H1 i H2 zavise od koncentracije uzorka, pH vrednosti i jonske jačine kontinualne faze. Pri koncentraciji od 1 g/100 cm³ i Ic=0 mol/dm³ pripremljene emulzije su stabilne na svim pH osim emulzije IPST na pH 5. Sve emulzije podležu gravitacionoj nestabilnosti.</p> / <p>Pumpkin (Cucurbita pepo) seed is rich source of both, oil and proteins. Once the oil has been extracted, proteins concentrate in oil cake, a by&ndash;product of the oil<br />extraction process, where their content can reach up to 65%. Pumpkin seed proteins are desirable ingredient in food, pharmaceutical and cosmetic industry due to their pharmacological activities and high biological value. Moreover, since many of products of these industries are, in colloidal terms, emulsions, pumpkin seed proteins could serve as surface active materies. However, colloidal functionality of pumpkin seed proteins is still underestimated for their globular structure which entails inferior functional properties to functional properties of proteins with more flexible structure. Based on that, the aim of this dissertation is to investigate functional properties of pumpkin seed protein isolate, adsorption and emulsifying properties, in the first place, and then to investigate the influence of modification of the protein structure, by means of enzymatic hydrolysis, on the aforementioned properties.<br />Pumpkin seed protein isolate, IPST, and two enzymatic hydrolysates, H1 and H2, were prepared. IPST, H1 and H2 were characterized by determination of moisture, ash and protein content, then, by determination of protein recovery, molecular mass and zeta potential. Influence of the protein/peptide concentration (0.0001&ndash;1 g/100 cm³), pH (3&ndash;8) i ionic strength (0&ndash;1 mol/dm³ NaCl) on the solubility and adsorption properties: dynamic interfacial (oil/water) pressure, static surface (air/water) and interfacial (oil/water) pressure, adsorption kinetics and interfacial dilatational properties, was<br />investigated next. In the end, influence of the aforementioned pharameters on the emulsifying properties of IPST, H1 and H2 was investigated. Emulsifying properties of IPST, H1 and H2 were discussed in terms of mean droplet diameter, droplet size distribution and emulsion stability.<br />Protein recovery of IPST was determined to be 65 % higher than recovery of H1 and H2. Solubility of IPST was the lowest at pH 5, what presents the isoelectric point. The enzymatic hydrolysis of IPST significantly increased solubility, especialy at the isoelectric point. Increase in the ionic strenght led to salting&ndash;in or salting&ndash;out effect depending on pH of the sample. Three investigated samples, IPST, H1 and H2 exhibited surface activity, however, sufrace/interfacial pressure of H1 and H2 were found to be less influenced by change in pH or ionic strenght of the solution in comparison to the IPST. Once adsorbed to the interface IPST and both hydrolysates form interfacial film with dominant elastic component. Emulsifying properties of IPST, H1 and H2 depend on the concentration, pH and ionic strength of the continuous phase. Stabile emulsions were formed at concentration of 1 g/100 cm3 and Ic=0 mol/dm³ regardless of pH, with the exception of the IPST at pH 5. All emulsions were susceptibile to gravitational separation.</p>

No description available.

Les émulsions représentent une large gamme de produits alimentaires, cosmétiques et pharmaceutiques. Pour assurer leur stabilité, une interface chargée de tensioactif est nécessaire. Cette interface constitue une barrière contre la coalescence mais gène la libération des principes actifs encapsulés. Dans cette thèse, une nouvelle méthode d’émulsification est développée. Elle consiste à utiliser des ultrasons à hautes fréquences (UHF) (1,7MHz) qui permettent d’avoir des émulsions stables sans émulsifiants tout en évitant les effets mécaniques violents de la cavitation acoustique présente aux basses fréquences. L’étude des répartitions granulométriques a montré une diminution significative de la taille des gouttelettes d’huile au cours du temps de traitement par ultrasons de hautes fréquences. Le suivi du pH des émulsions montre une forte diminution et une charge de surface importante des gouttelettes est enregistrée ce qui montre une accumulation d’ions OH- à l’interface l'huile/eau conduisant à la stabilité des gouttelettes dans l'émulsion. La conductivité des émulsions diminue durant l’émulsification traduisant une baisse de la quantité d’ions en solution, ce qui indique la formation de la couche contre ions (charge positive) autour de la structure des OH-. Les résultats montrent une stabilisation électrostatique des émulsions obtenue par la formation d’une double couche ionique autour des gouttelettes d’huile. Contrairement aux procédés d’émulsification standard, les émulsions faites par ce procédé montrent une stabilité de 30 jours à 37°C. L’utilisation des émulsions sans émulsifiant faites par UHF pour la vectorisation de CoQ10 montre une prolifération cellulaire plus élevée que dans le cas des émulsions avec émulsifiant. Une étude approfondie des émulsions sans émulsifiant par diffusion des rayons X aux petits angles (SAXS) et par résonance magnétique nucléaire (RMN) a été réalisée et comparée à des émulsions contenant un ou plusieurs émulsifiants. L’étude SAXS montre clairement l’absence de micelles de tensioactifs pour les émulsions sans émulsifiants et les résultats de la RMN montrent l’absence de la signature des tensioactifs et des phospholipides dans les émulsions faites par ultrasons de hautes fréquences. Par ailleurs, la RMN montre l’absence d’interaction entre des différents constituants de l’émulsion et aussi l’absence de structure néoformées / Emulsions are systems containing two immiscible liquids, one dispersed as droplets (dispersed phase) throughout the other (continuous phase). When emulsifier is added, it may interact with the other formulations compounds creating new emulsion properties. Therefore, it becomes difficult to study the role of oil phase alone on emulsion properties. In this thesis, emulsifier free emulsion was developed with high frequency ultrasounds (HFU) generated by piezoelectric ceramic transducer vibrating at 1.7 MHz. pH measurement showed significant decrease and negative electrophoretic mobility showed the accumulation of OH- at oil/water interface leading to droplets stability in the emulsion. Emulsions conductivity showed a decrease of the ions quantity in solution, which indicated formation of positive charge layer around OH- structure. They constituted a double ionic layer around oil particles providing emulsion stability. This study showed a strong correlation between turbidity measurement and proportion of emulsified oil. Unlike standard emulsification methods, emulsions made this process demonstrates stability for 30 days at 37 °C. The use of emulsions without emulsifier made by HFU for vectoring CoQ10 shows a higher cell proliferation in the case of emulsion without emulsifier. A study of emulsions without emulsifer by small angle X-ray scattering (SAXS) and nuclear magnetic resonance (1H NMR) was performed and compared to emulsions containing emulsifiers. NMR analysis showed no interactions between different compounds and the HFU manufacturing process did not cause chemical degradation or neoformed compounds. SAXS showed a thin interface between two phases with different electronic density (water/oil) for emulsions with and without emulsifiers. For emulsion with emulsifiers SAXS showed surfactant micelles diffusion signal which doesn’t appear in the emulsion without emulsifiers

Vanderghem Caroline. (2009). La membrane du globule gras du lait : études physico-chimiques et sa valorisation technofonctionnelle dans les babeurres (Thèse de doctorat en Anglais). Gembloux, Belgique, Faculté Universitaire des Sciences Agronomiques de Gembloux. 198p., 14 tabl., 59 fig. Résumé La membrane du globule gras du lait (MGGL) est une structure complexe qui enveloppe, protège et délivre des composants bioactifs et des nutriments dune façon efficace au nouveau-né. Sa structure est unique par rapport à dautres systèmes biologiques de transport de lipides. Lobjectif général de ce travail a été de contribuer à augmenter les connaissances et la compréhension de cet émulsifiant naturel. La première partie de cette thèse concerne létude de la structure de la MGGL. Limportance des protéines membranaires concernant la stabilité et leur disposition dans la MGGL ont été étudiés. Les protéines de la MGGL sont présentes en petite quantité dans le lait et une technique de pré-fractionnement simpose afin de les isoler par rapport aux autres protéines du lait (caséines et protéines du lactosérum). Une technique dextraction qui a été développée dans notre laboratoire a été testée afin disoler la MGGL de la crème laitière. Une analyse détaillée a révélé que cette procédure est très bien adaptée pour lélimination dun maximum de protéines du lait écrémé. Une approche protéomique a été établie et a permis lidentification de protéines majeures de la MFGM ainsi que dautres protéines mineures (GTP-binding proteins, annexins, actin) afin de compléter le protéome. Par la suite, différentes protéases ont été testées en vue dobtenir différents degrés et/ou sélectivité dhydrolyse des protéines de la MGGL. La distribution asymétrique des protéines de la MGGL a été étudiée par une approche basée sur lattaque protéolytique du globule gras natif. Sur base de nos résultats et des données bibliographiques récentes, un nouveau modèle de la structure de la MGGL est proposé. La deuxième partie de cette thèse est consacrée à évaluer les propriétés technofonctionnelles de la MGGL dans les babeurres. Les propriétés interfaciales, moussantes et émulsifiantes du babeurre sont comparées à dautres ingrédients laitiers comme le lait écrémé et le concentré protéique de lactosérum. Nos résultats montrent le bon pouvoir émulsifiant du babeurre en comparaison des autres ingrédients laitiers. Dans les émulsions recombinées, la stabilité envers le crémage a été améliorée et les membranes ont présenté une meilleure résistance face à la coalescence. Les résultats sur la tension interfaciale et les propriétés rhéologiques interfaciales ont été mis en relation avec certaines propriétés des mousses et des émulsions. Vanderghem Caroline. (2009). The milk fat globule membrane: physico-chemical studies and its techno-functional valorisation in buttermilk (Thèse de doctorat). Gembloux, Belgium, Gembloux Agricultural University, 198p., 14 tabl., 59 fig. Summary The milk fat globule membrane (MFGM) is a complex structure that surrounds, protects and delivers bioactive compounds and nutrients in an efficient manner to the neonate. Its structure is unique in relation with any other biological lipid transport system. The overall aim of this work was to contribute to increase the knowledge and comprehension of this natural emulsifier. The first part of this thesis concerned the study of the structure of the MFGM. Membrane proteins were targeted and their importance regarding stability and disposition in the MFGM was studied. MFGM proteins are present at low concentrations in milk and a pre-fractionation of the sample is required in order of MFGM proteins to be visible among other milk proteins (caseins and whey proteins). A mild procedure developed in our laboratory was tested in order to isolate MFGM from cream. Detailed analysis revealed that this procedure is very well suited for the elimination of a maximum of skim milk proteins. A proteomic approach was established and allowed the identification of the most important MFGM proteins and additional minor MFGM proteins for additional completion of the proteome (GTP-binding proteins, annexins, actin). Subsequently, different proteases were screened in an attempt to obtain different degrees and/or selective proteolysis of MFGM proteins. Asymmetric arrangement of MFGM proteins was studied with an approach based on the proteolytic attack on the native fat globule. Based on our results and recent bibliographic data, an updated model of the MFGM structure was proposed. The second part of this thesis was devoted to assess the techno-functional properties of the MFGM in buttermilks. Interfacial, foaming and emulsifying properties of buttermilk were assessed and compared to classic milk ingredients such as skim milk and whey protein concentrate. Our results highlighted that buttermilk possesses good emulsifying power compared to other milk ingredients. In buttermilk recombined emulsions stability towards creaming was improved and the recombined membrane presented a great resistance to coalescence. Results of the interfacial pressure and the interfacial rheological properties were related to some foams and emulsions properties.