Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 224 pages. / Thesis (Ph.D.)--University of South Florida, 2004. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Particle Nucleation is the forcing function in the Emulsion Polymerization processes and it plays an important role in dictating the final properties of the latex produced. Identification of the main nucleation sites and characterizing them in terms of their size and composition is important for elucidating the mechanism of particle nucleation. This research focuses on identifying the most likely nucleation locus in emulsion polymerization processes by characterizing the initial conditions of the reaction mixture. In order to achieve this objective, a methodology was devised, which used a non-reacting model emulsion system instead of the original emulsion. The model emulsion system selected has the same dispersion properties as that of the monomer emulsion system, but different optical properties. The model emulsion system enabled the study of the distribution of the emulsifier using Uv vis spectroscopy. / ABSTRACT: This approach also eliminated the time constraint associated with sampling during a polymerization reaction. A quantitative deconvolution using the turbidity equation, was done on the transmission Uv vis spectra of the emulsions. This enabled the characterization of the emulsions in terms of their particle size distribution, particle number and the composition of the droplet populations comprising them. The studies conducted provide the experimental evidence for a previously unidentified nano-droplet population of size range 30 to 100nm in diameter. To further support this experimental evidence, calculations were performed to obtain the emulsifier distribution over the nano-droplet population. The calculations suggest the probability of existence of the nano-droplet population to be much higher than the probability of the existence of the swollen micelles. / ABSTRACT: The results, depending upon the emulsification conditions, indicate the presence of about 15 % to 80% of the dispersed phase in the nano-droplet population. The large interfacial area offered by the nano-droplet population due to their high particle numbers and high percentage of the dispersed oil phase in them, make them the most probable particle nucleation loci in emulsion polymerization processes. Designed experiments were performed to experimentally observe the changes in the nano-droplet populations. The effects of the process variables, namely pH, surfactant concentration and temperature, on the size and compositional characteristics of the nano-droplet population were investigated. The results suggested that the surfactant to oil ratio was the dominating factor governing the size and the weight percent of the dispersed phase in the nano-droplet population. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Thesis (M.S.)--University of Massachusetts Amherst, 2009. / Open access. Includes bibliographical references (p. 59-64).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references. Available also in a digital version from Dissertation Abstracts.

Nuclear power waste contains radioactive isotopes with long half lives and the problem lies in the fact that the lanthanides and actinides must be separated before the nuclear waste can be reprocessed. Transuranic Extraction (TRUEX), a liquid-liquid extraction method, has been developed but fails to separate the lanthanide and actinides and creates large volumes of liquid waste. It has been shown that attaching three CMPO (carbamoyl phosphine oxide) ligands used in the TRUEX process to a calixarene increases the separation and extraction efficiency of the system. The research goal is to attach the CMPO ligand to a polymer to make a membrane to be used in nuclear waste remediation. The triblock polymer system has been designed to have a cross-linking group to create the membrane structure, a solubilizing group to improve the flow of aqueous media through the membrane, and the CMPO ligand to chelate actinides. This paper describes the design of the polymer, its synthesis, and my research data. / text

Vapour-Liquid Equilibrium (VLE), Liquid-Liquid Equilibrium (LLE) and Vapour-Liquid-Liquid Equilibrium (VLLE) are of special interest in chemical engineering as these types of data form the basis for the design and optimization of separation processes such as distillation and extraction, which involve phase contacting. Of recent, chemical companies/industries have required thermodynamic data (especially phase equilibrium data) for chemicals that are expensive or costly to synthesize. Phase equilibrium data for such chemicals are scarce in the open literature since most apparatus used for phase equilibrium measurements require large volumes (on average 120 cm3) of chemicals. Therefore, new techniques and equipment have to be developed to measure phase equilibrium for small volumes across reasonable temperature and pressure ranges. This study covers the design of a new apparatus that enables reliable vapour pressure and equilibria measurements for multiple liquid and vapour phases of small volumes (a maximum of 18 cm3). These phase equilibria measurements include: VLE, LLE and VLLE. The operating temperature of the apparatus ranges from 253 to 473 K and the operating pressure ranges from absolute vacuum to 1600 kPa. The sampling of the phases are accomplished using a single Rapid-OnLine-Sampler- Injector (ROLSITM) that is capable of withdrawing as little as 1μl of sample from each phase. This ensures that the equilibrium condition is not disturbed during the sampling and analysis process. As an added advantage, a short equilibrium time is generally associated with a small volume apparatus. This enables rapid measurement of multiple phase equilibria. A novel technique is used to achieve sampling for each phase. The technique made use of a metallic rod (similar in dimension to the capillary of the ROLSITM) in an arrangement to compensate for volume changes during sampling. As part of this study, vapour pressure and phase equilibrium data were measured to test the operation of the newly developed apparatus that include the following systems: • VLE for 2-methoxy-2-methylpropane + ethyl acetate at 373.17 K • LLE for methanol + heptane at 350 kPa • LLE for hexane + acetonitrile at 350 kPa • VLLE for hexane + acetonitrile at 348.20 K New experimental vapour pressure and VLE data were also measured for systems of interest to petrochemical companies. These measurements include: • VLE for methanol + butan-2-one at 383.25, 398.14 and 413.20 K ABSTRACT • VLE for ethanol + butan-2-one at 383.26, 398.23 and 413.21 K • VLE for ethanol + 2-methoxy-2-methylbutane at 398.25 and 413.19 K • VLE for ethanol + 2-methylpent-2-ene at 383.20 K These measurements were undertaken to understand the thermodynamic interactions of light alcohols and carbonyls as part of a number of distillation systems in synthetic fuel refining processes which are currently not well described. Two of these above mentioned systems include expensive chemicals: 2-methoxy-2-methylbutane and 2-methylpent-2-ene. The experimental vapour pressure data obtained were regressed using the extended Antoine and Wagner equations. The experimental VLE data measured were regressed with thermodynamic models using the direct and combined methods. For the direct method the Soave-Redlich-Kwong and Peng-Robinson equations of state were used with the temperature dependent function (α) of Mathias and Copeman (1983). For the combined method, the virial equation of state with the second virial coefficient correlation of Tsonopoulos (1974) was used together with one of the following liquid-phase activity coefficient model: TK-Wilson, NRTL and modified UNIQUAC. Thermodynamic consistency testing was also performed for all the VLE experimental data measured where almost all the systems measured showed good thermodynamic consistency for the point test of Van Ness et al. (1973) and direct test of Van Ness (1995). / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2011.

Thesis (Ph.D.)--University of Melbourne, Dept. of Mathematics and Statistics, 2007. / Typescript. Includes bibliographical references (leaves 143-151).

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 248-269). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 152-163).

Aujourd’hui, une large part des métaux utilisés par l’industrie provient généralement des mines. Certains, dits stratégiques, pourraient présenter un risque d’approvisionnement voire d’épuisement des ressources naturelles. Ces métaux sont généralement utilisés dans des processus dispersifs, et se retrouvent répartis de façon inégale, avec d’autres métaux, dans des matrices toujours plus complexes, ce qui rend leur récupération couteuse en termes de procédés et d’énergie. Que ce soit pour des raisons stratégiques, économiques ou sociétales, il apparait que le recyclage des métaux est amené à devenir une activité importante dans le futur. L’approche hydrométallurgique, et en particulier l’extraction-séparation liquide-liquide, est une technique adaptée et éprouvée à ce jour pour répondre au recyclage des métaux. Ce travail de thèse s’intéresse au développement et l’étude de systèmes moléculaires fluorés pour l’extraction et la séparation de métaux par une approche liquide-liquide. La modularité de la partie fluorée de ce type de système moléculaire permet l’étude des diverses interactions (complexations, supramoléculaires) importantes d’un point du vue fondamental dans l’extraction liquide-liquide de métaux. De plus, leurs propriétés physico-chimiques (miscibilité,…) permettent d’envisager le design de procédés innovants dans le domaine de la séparation liquide-liquide, comme la mise en œuvre de systèmes tri-phasiques. Pour cela, deux séries de malonamides fluorés avec des espaceurs de taille variable, entre la tête complexante et le groupement perfluoré, ont été synthétisés. La modulation par l’espaceur de l’effet inductif des chaines perfluorées sur les propriétés physico-chimiques des extractants et sur la complexation d’un métal a été étudiée. De même, l’influence de certains paramètres d’extraction comme la charge en extractant, en acide et l’influence du diluant ont été caractérisés. La comparaison avec les ligands homologues hydrogénés a été effectuée, et les limites des différents systèmes établies. Une série de phosphates de trialkyles a également été étudiée et appliquée à un système tri-phasique d’extraction liquide-liquide. Des résultats préliminaires valident de manière encourageante l’approche choisie. / A large part of the metals used by the industry is still coming from mines. Some metals, called strategic metals, may encounter a supply risk or even a total depletion of natural resources. They are usually used in dispersive way which make their recovery complicated, costly and energy intensive since they are in unequal amount, with other metal, in ever more complex matrices. Whether for strategic, economic or societal reason, the metal recycling is about to become an important industry in a near future. Hydrometallurgical processes, and liquid-liquid extraction in particular, are a robust technic giving answer to some of the recycling challenge. Our aim was to develop and study some fluorinated system for the extraction and the separation of metal through liquid-liquid approach. The tenability of the fluorinated part of these system allow the study of multiple interaction (complexation or supramolecular ordering) important in a fundamental point of view in liquid-liquid extraction. Physical and chemical properties such as their miscibility allow the development of new processes in the solvent extraction field such as triphasic liquid extraction system. To this end, two series of fluorinated malonamides with various spacer length between the complexing head and the fluorinated moiety were synthetized. The modulation, through the spacer, of the inductive effect of the fluorinated chain on the physical and chemical properties of the extractant and the complexation of the metal was studied. The influence of various extraction parameters such as the concentration in extractant, the acid and the diluent were characterized. The comparison of these malonamides with their hydrogenated homologues was done and the limits of these systems established. A family of trialkylphosphate was developed and apply to a triphasic extraction system. Preliminary results confirm the approach.

abstract: A comprehensive and systematic investigation on the diffusion and phase behaviors of nanoparticles and macromolecules in two component liquid-liquid systems via Molecule Dynamic (MD) simulations is presented in this dissertation. The interface of biphasic liquid systems has attracted great attention because it offers a simple, flexible, and highly reproducible template for the assembly of a variety of nanoscale objects. However, certain important fundamental issues at the interface have not been fully explored, especially when the size of the object is comparable with the liquid molecules. In the first MD simulation system, the diffusion and self-assembly of nanoparticles with different size, shape and surface composition were studied in an oil/water system. It has been found that a highly symmetrical nanoparticle with uniform surface (e.g. buckyball) can lead to a better-defined solvation shell which makes the “effective radius” of the nanoparticle larger than its own radius, and thus, lead to slower transport (diffusion) of the nanoparticles across the oil-water interface. Poly(N-isopropylacrylamide) (PNIPAM) is a thermoresponsive polymer with a Lower Critical Solution Temperature (LCST) of 32°C in pure water. It is one of the most widely studied stimulus-responsive polymers which can be fabricated into various forms of smart materials. However, current understanding about the diffusive and phase behaviors of PNIPAM in ionic liquids/water system is very limited. Therefore, two biphasic water-ionic liquids (ILs) systems were created to investigate the interfacial behavior of PNIPAM in such unique liquid-liquid interface. It was found the phase preference of PNIPAM below/above its LCST is dependent on the nature of ionic liquids. This potentially allows us to manipulate the interfacial behavior of macromolecules by tuning the properties of ionic liquids and minimizing the need for expensive polymer functionalization. In addition, to seek a more comprehensive understanding of the effects of ionic liquids on the phase behavior of PNIPAM, PNIPAM was studied in two miscible ionic liquids/water systems. The thermodynamic origin causes the reduction of LCST of PNIPAM in imidazolium based ionic liquids/water system was found. Energy analysis, hydrogen boding calculation and detailed structural quantification were presented in this study to support the conclusions. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2017