This dissertation explores the potential of using perfluorocarbon emulsion droplets to add an ultrasound-sensitive element to drug delivery systems. These emulsion droplets may be induced to vaporize with ultrasound; during the rarefactional phase of an ultrasound wave, the pressure around the droplets may fall below the vapor pressure of the liquid forming the emulsion, providing a thermodynamic potential for vaporization. This ultrasound-induced phase change of the emulsion droplet could release therapeutics attached to the droplet surface or aid in drug delivery due to mechanical effects associated with vaporization and expansion, similar to the ability of cavitating bubbles to aid in drug delivery. In contrast to bubbles, stable emulsions can be formed at nano-scale sizes, allowing them to extravasate into tissues and potentially be endocytosed into cells. Perfluorohexane and perfluoropentane were selected to form the emulsions due to their relatively high vapor pressure, low water solubility, and biocompatibility. Acoustic droplet vaporization was explored for its potential to increase ultrasound-induced drug release from liposomes. Liposomes have proven to be versatile and effective drug carriers, but are not inherently responsive to ultrasound. eLiposomes, defined as a liposome with encapsulated emulsion droplets, were developed due to the potential of the expanding vapor phase to disrupt bilayer membranes. The resulting vesicle retains the advantages of liposomes for drug delivery, while adding an ultrasound-sensitive element. eLiposomes were loaded with calcein, a fluorescent molecule, as a model drug in order to quantify ultrasound-mediated drug release compared to release from conventional liposomes. Upon exposure to ultrasound, eLiposomes typically released 3 to 5 times as much of the encapsulated load compared to conventional liposomes, with some eLiposome samples approaching 100% release. Emulsion droplets were also added to the outside of conventional liposomes, but resulted in little to no increase compared to control samples without emulsions. Lastly, in vitro experiments were performed with HeLa cells to explore the ability of emulsion droplets and eLiposomes to deliver calcein inside of cells. Calcein delivery to the cytosol was accomplished, and the emulsion-containing samples demonstrated the ability to aid in endosomal escape.

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.

Water-borne latex coatings represent a safer, more user-friendly, and environmentally responsible alternative to solvent-borne coatings, and are growing in popularity each year. However, these coatings often exhibit unfavorable performance when exposed to water for extended periods of time. This prolonged exposure often results in water uptake, which may give rise to other detrimental effects such as a decrease in modulus, blushing or water-whitening, reduced serviceable life, and softening of the film. In this study, various polymer composition latex design spaces are studied to develop an understanding of how water uptake can be modulated and minimized using common synthetic approaches. Factors including monomer selection, particle size, polymer molecular weight, crosslinking density, surfactant choice and particle stabilization, processing variables and Tg are considered. In addition, some formulation modifications including PVC, film thickness, and choice of coalescent package are explored to gain a more comprehensive understanding of final product performance. In quantifying the total water uptake of the films, gravimetric analysis tends to be the preferred method employed in the coatings industry. However, other analytical approaches can be used to better understand the effect that water has on the properties of the film. These methods may include differential scanning calorimetry, electrochemical impedance spectroscopy, immersion testing using dynamic mechanical analysis, and others. In the work, it has been shown that interparticle crosslinking, surfactant, and monomer selection can have an extreme influence on the water uptake of free films. Film samples exhibit a range of water uptake values from nearly 200% to less than 5% over a one-week soak in deionized water. It is thought that the surfactant may provide hydrophilic channels that allow water to v penetrate the film and form heterogeneous domains within the coating. These domains then grow and scatter light, leading to water-whitening and an increase in mass when compared to the dry film. Utilizing monomers with differing relative solubilities in water, such as methyl methacrylate and styrene, further allow control of this effect. Interparticle crosslinking via keto-hydrazide crosslinking, which is achieved during the film formation process, can also prevent the formation and growth of these large water domains, thus resulting in better performing films.

This is a `sandwich thesis' comprising three distinct research streams I have pursued during the course of my master's degree. The first two streams have concluded, each resulting in a manuscript that is presented as a separate chapter of this thesis. The third research stream is ongoing, but preliminary results are presented in another chapter of this thesis. The first research stream presented in this thesis concerns the development of a technique to produce droplets with diameters as small as 5 microns with an extremely narrow size distribution in comparison to other methods. Other advantages of this technique, known as he snap-offf method, include its simplicity and ease of tuning droplet size. The results of this research are presented in chapter 3 in the form of a manuscript that is currently in press. The second research stream of this thesis explores the physics that drive droplet snap-off. A model was developed to predict the size of droplets, dependent on fluid properties, system geometry, and fluid flow rate. Experiments examined each of these parameters in turn, providing a cohesive understanding of the mechanism behind droplet snap-off. Multiple unanticipated predictions of the model were also verified experimentally. This research is presented in chapter 4 as a manuscript that will be submitted shortly. The final research stream of this thesis investigates forces in emulsions as they relate to a transition from glassy to crystalline dynamics. Specifically, 2D aggregates of droplets were compressed with micropipettes, providing both imaging of cluster evolution, as well as the force applied during compression. This research stream has demonstrated qualitative differences between droplet clusters that differ in composition so as to behave like crystals, glasses, or intermediate states. More quantitative analysis is required before this research stream is ready to be published. Preliminary results are presented in chapter 5. / Thesis / Master of Science (MSc)

In this thesis, copolymer latexes comprised of various fractions of methyl methacrylate (MMA) and butyl acrylate (BA) were synthesized through surfactant-free emulsion polymerization. A carbon dioxide responsive comonomer, 2-(diethyl)aminoethyl methacrylate (DEAEMA) was also used with an equimolar amount of hydrochloric acid (HCl) to promote its partitioning into the water phase. Changing the MMA/BA fraction gave control over the resulting glass transition temperature of the particles. Following polymerization, the particles from the resulting latexes could be effectively coagulated be adding a small amount of caustic soda, and could be easily separated from water. After washing the particles with deionized water, CO2-redispersibility of the latex particles was evaluated as a function of their respective glass transition temperature. It was determined that coagulated particles higher in MMA content could be easily redispersed into carbonated water with the aid of ultrasonication, preparing stable latexes of the same solids content. For latex particles with a glass transition temperature below ambient conditions, coagulation led to the fusion of individual particles, which inhibited their ability to be redispersed. By conducting the coagulation and redispersion cycles at temperatures cold enough for the BA-rich particles to be below their glass transition temperature, these same latex particles could be effectively redispersed. The relationship between the glass transition temperature of the latexes and their CO2-redispersibility provides guidance from a practical sense for the applicability of CO2-sensitive amine-functionalized molecules in developing industrially useful CO2-redispersible latex products. / Thesis / Master of Applied Science (MASc) / This work examines special type of coagulatable and redispersible latex paint that could potentially reduce the costs in storing and transporting latex paint products. After synthesizing the latex, the nanoscopic polymer particles that make up the latex could be easily coagulated by adding a small amount of sodium hydroxide. Following this, water could be removed and a condensed form of the paint was obtained. The ability to redisperse the particles back into carbonated water was subsequently examined based on the softness of the polymer particles by synthesizing a series of latexes with different fractions of methyl methacrylate (MMA) and butyl acrylate (BA). After synthesis, the latexes that contained higher fractions of MMA were comprised of particles that were less soft than the BA-rich latexes, which made the redispersibility of these particles much easier. Upon coagulation, BA-rich particles fused together upon contact and could not be separated, hence inhibiting their redispersibility. When these same BA-rich latex particles were coagulated at colder temperatures, fusion was inhibited and the redispersibility of particles was greatly improved. Overall, the particles were found to be redispersible if the glass transition temperature of polymer chains within the particles was lower than ambient temperature. Since softer polymer particles are often used for latex paint-based applications, this work provides important and relevant insight in the development of industrially useful CO2-redispersible products.

The physicochemical properties of pyrolysis oil have been shown to be dependent on feedstock composition. Accelerated aging tests were performed to understand the effects of feedstock, condensate fraction collected, and filtration on the stability of pyrolysis oil. In this study, pyrolysis oil properties critical for downstream upgrading were measured and compared for different feedstock weight ratios of pine clearwood and pine bark. Post-condensation filtration of pyrolysis oil was evaluated using both lab-scale and pilot plant-scale centrifugal filtration with several operational parameters evaluated. The pilot-plant centrifuge can be used as a three-phase separator [light liquid-heavy liquid-solids] or a two-phase clarifier [liquid-solid]. Since pyrolysis oil is an oil-water micro-emulsion, separation of the heavy and light liquid phases is difficult; therefore, emulsion destabilization studies were performed in concert with centrifugation. Physicochemical properties were monitored to determine the impact of the production and processing parameters on the oil properties critical to biofuel applications.

No description available.

No description available.

No description available.

No description available.