This dissertation focuses on the preparation of polymeric monolithic capillaries for ion exchange chromatography of peptides and proteins, since polymeric monoliths have shown promise for providing improved protein separations. Characteristics of monolithic columns include low back pressure, simplicity of fabrication and biocompatibility. Preparation of strong and weak cation-exchange monolithic stationary phases in 75 μm I.D. capillaries by direct in situ copolymerization was achieved using various functional monomers including sulfopropyl methacrylate, phosphoric acid 2-hydroxyethyl methacrylate, bis[2-(methacryloyloxy)ethyl] phosphate and 2-carboxyethyl acrylate with polyethylene glycol diacrylate and other PEG materials. The resulting monoliths provided excellent ion exchange capillary LC of peptides and proteins with good run-to-run [relative standard deviation (RSD) < 1.99%] and column-to-column (RSD < 5.64%) reproducibilities. Narrow peaks were obtained and peak capacities of over 20 were achieved. Dynamic binding capacities of over 30 mg/mL of column volume for lysozyme were measured. A single monomer was used to synthesize a phosphoric acid containing monolith to improve its stability and reproducibility. The monolith was synthesized from only BMEP in 75 μm I.D. UV transparent fused-silica capillaries by photo-initiated polymerization. A dynamic binding capacity (lysozyme) of approximately 70 mg/mL of column volume was measured. Efficiencies of 52,900 plates/m for peptides and 71,000 plates/m for proteins were obtained under isocratic conditions. Good reproducibilities were achieved. Zwitterionic monolithic columns based on photo-initiated copolymerization of N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betain and poly(ethylene glycol) diacrylate were prepared in 75 μm I.D. fused silica capillaries for hydrophilic interaction chromatography. Inverse size exclusion chromatography was used to characterize the pore structure of the resulting monolith. A typical hydrophilic interaction chromatography mechanism was observed when the organic content in the mobile phase was higher than 60%. Good separations of amides, phenols, and benzoic acids were achieved. The effects of mobile phase pH, salt concentration, and organic modifier content on retention were investigated.

Liposomes have the ability to carry and deliver both hydrophilic and hydrophobic drugs and to protect them when injected into the circulatory system. They thus provide an attractive vehicle for drug delivery. However, problems of rapid clearance and inability to target liposomes to specific cells and tissues remain unresolved. Rapid clearance has been attributed to adsorption of opsonins, and one approach to reduce such adsorption is to create sterically stabilized liposomes by modifying the surface with polyethylene glycol (PEG) or dextran. To deliver their drug "payload" liposomes must interact with the membranes of target cells. Interactions with cellular components of the vascular walls have been observed for various sulfated polysaccharides such as heparin and functionalised dextrans. Based on the above considerations, the purpose of this work was to investigate the ability of various polymeric modifiers on liposomes to reduce protein adsorption and promote incorporation into target cells. Liposomes of composition PC/PEI cholesterol (70/10/20 mol %) were surface modified with PEG, dextran, heparin, and functionalised dextran. Protein adsorption was studied from solutions of IgG in buffer and from plasma. Adsorption from buffer was measured by radio labelling methods. For the plasma work, a total protein assay was used to determine the amount of protein adsorbed to the liposome surface, while gel electrophoresis and immunoblotting methods were used to examine the profiles of protein binding. Liposome incorporation into vascular smooth muscle and endothelial cells was evaluated using fluorescent labelling and radio labelling techniques. The IgG adsorption studies showed reduced adsorption on all polymer-modified liposomes. Plasma adsorption data showed that adsorbed protein layer compositions on the different liposome types were similar, but different from that of the plasma itself, showing that the plasma was fractionated on the liposome surfaces. Cell interaction studies showed that liposomes modified with dextran and sulfated dextran were incorporated into both cell types. The unmodified, PEG-and heparin-modified liposomes were not incorporated to any significant extent. / Thesis / Master of Engineering (ME)

Dewatering fine coal is needed in many applications but has remained a great challenge. The hydrophobic-hydrophilic separation (HHS) method is a powerful technology to address this problem. However, organic solvents in solvent-coal slurries produced during HHS must be recovered for the method to be economically viable. Here, the experimental studies of recovering solvents from pentane-coal and hexane-coal slurries by combining liquid-solid filtration and in-situ vaporization and removing the solvent by a carrier gas (i.e., drying) are reported. The filtration behaviors are studied under different solid mass loading and filtration pressure. It is shown that using pressure filtration driven by 20 psig nitrogen, over 95% of solvents by mass in the slurries can be recovered, and filtration cakes can be formed in 60 s. The drying behavior was studied using nitrogen and steam at different temperatures and pressures. It is shown that residual solvents in filtration cakes can be reduced below 1400 ppm within 10 s by 15 psig steam superheated to 150C, while other parameter combinations are far less effective in removing solvents. Physical processes involved in drying and the structure of solvent-laden filtration cakes are analyzed in light of these results. / Master of Science / Coal particles below a certain size are discarded to waste tailing ponds as there is no economically viable method for processing them. However, a new process called hydrophobic-hydrophilic separation offers a solution to this problem. A hydrophobic solvent is used to displace water from a coal-water slurry, and it is then easier and cheaper to filter and dry this new coal-solvent slurry. In this work experimental studies of recovering solvents from pentane-coal and hexane-coal slurries by combining filtration and drying are reported. The filtration behaviors are studied under different solid mass loading and filtration pressures. It is shown that using pressure filtration driven by 20 psig nitrogen, over 95% of solvents by mass in the slurry can be recovered, and filtration cakes can be formed in 60 s. The drying behavior was studied using nitrogen and steam at different temperatures and pressures to evaporate any remaining solvents. It is shown that the remaining solvents in filtration cakes can be reduced below 1400 ppm within 10 s by using 15 psig steam superheated to 150C as a drying medium, while other parameter combinations are far less effective in removing solvents. Physical processes involved in drying and the structure of solvent-laden filtration cakes are analyzed in light of these results.

High performance engineering materials, poly(arylene ether)s, having very good mechanical properties, excellent oxidative and hydrolytic stability are promising candidates for alternative materials used in the field of Proton Exchange Membrane Fuel Cells (PEMFCs) and Reverse Osmosis (RO) applications. In particular, wholly aromatic sulfonated poly(arylene ether sulfone)s are of considerable interest in the field of PEMFCs and RO, due to their affordability, high Tg, and the ease of sulfonation. Proton exchange membrane fuels cells (PEMFCs) are one of the primary alternate source of energy. A Proton exchange membrane (PEM) is one of the key component in a PEMFC and it needs to have good proton conductivity under partially humidified conditions. One of the strategies to increase proton conductivity under partially RH conditions is to synthesize hydrophobic-hydrophilic multiblock copolymers with high Ion exchange capacity (IEC) values to ensure sufficient ion channel size. In this thesis two multiblock systems were synthesized incorporating trisulfonated hydrophilic oligomers and were characterized in the first two chapters of the thesis. The first multiblock system incorporated a non-fluorinated biphenol-based hydrophobic block. The second study was focused on synthesizing a fluorinated benzonitrile-based hydrophobic block. A fluorinated monomer was incorporated with the aim to improve phase separation which might lead to increased performance under partially humidified conditions. The third study featured synthesis and characterization of a novel hydroquinone-based random copolymer system precursor, which after post-sulfonation, shall form mono-sulfonated polysulfone materials with potential applications in reverse osmosis. The ratio of the amount of hydroquinone incorporated in the copolymer were varied during the synthesis of the precursor to facilitate control over the post-sulfonation process. The simple and low cost process of post-sulfonating the random copolymer enables the precursor to be a promising material to be used in the reverse osmosis application. / Master of Science

The time-dependent wettability of nickel nanorod arrays was studied by measuring their water contact angles as a function of "aging" time in air. The nickel nanorod arrays were deposited on silicon substrates by DC magnetron sputtering using an oblique angle of 85° with respect to the substrate normal. By changing the deposition time from 10 to 90 min., the diameter, height, and separation of the nanorods were varied. The water contact angles of each sample were then periodically measured from a minimum aging time of 30 min. after deposition and exposure to air, up to a maximum aging time of three months. The initial water contact angles for all samples were approximately equal to 8o, indicating that the nickel nanorod arrays were initially superhydrophilic. As the samples aged in air, however, they all showed increasing contact angles as a function of time that were nonlinear with different rates. The results can be grouped into two categories: thinner samples with shorter deposition times (10 to 55 min) demonstrated faster rates of increase in contact angle, and thicker samples with longer deposition times (60 and 90 min.) showed slower rates. The increase in contact angle with time indicates that the Ni nanorods become more hydrophobic with aging time in air. Surface chemical analysis demonstrates that this increase in hydrophobicity may be due to oxidization and hydrocarbon contamination, which depend on the nanorod morphology. X-ray photoelectron spectroscopy results indicate that thinner samples (10-55 min. deposition time) have more adsorbed carbon as compared to thicker samples (60 and 90 min.). It appears that the reactivity of the Ni nanorods with air ambient is enhanced for shorter, smaller-diameter nanorods.

Phenylephrine (PE) is the most commonly used over-the-counter nasal decongestant. The problem associated with phenylephrine is that it undergoes extensive first pass metabolism in the intestinal gut wall leading to its poor and variable oral bioavailability. This research project aims at developing strategies in order to increase the oral bioavailability of PE by co-administration of GRAS compounds. A HILIC assay method was developed to detect the parent drug, phenylephrine (PE) and its sulfate metabolite (PES).The enzyme kinetic studies were done with phenolic dietary or GRAS compounds using LS180 human intestinal cell model, recombinant SULT enzymes and human intestinal cytosol (HIC). From the screening studies done, one inhibitor was selected in order to study the mechanism of inhibition. In conclusion the studies done in vitro provided a basis in order to predict in vivo intrinsic clearance through the sulfation pathway.

O propósito deste trabalho é aumentar o conhecimento existente sobre as interações dielétricas da água confinada em materiais hidrofílicos, no regime de baixas temperaturas. Os materiais hidrofílicos (sílica gel, gesso, colágeno e álcool polivinílico - PVA) foram analisados com os recursos disponíveis na técnica de Espectroscopia de Impedância - permissividade dielétrica e impedância elétrica. Como objetivo especifico procurou-se estabelecer experimentalmente o papel das ligações hidrogênio nos processos de condução observados na água confinada e verificar a existência da transição dinâmica da água super-resfriada em T = -45ºC (228K). As substâncias examinadas possuem redes ou cadeias moleculares, com grupos polares superficiais capazes de se ligarem às moléculas de água por meio de ligações hidrogênio. Em espaços restritos de natureza hidrofílica, a água pode ser super-resfriada além do ponto de nucleação homogênea, permanecendo líquida para temperaturas inferiores a 0ºC. O entendimento de sistemas envolvendo materiais hidrofílicos - tais como sólidos, géis e macromoléculas - e a água, contribui para o desenvolvimento de novos materiais e para o entendimento dos sistemas vivos. De acordo com os resultados obtidos a condução dos íons na água confinada se dá por meio da rede formada, via ligações hidrogênio, entre as moléculas de água e a cadeia dos materiais. O espectro elétrico dos materiais estudados exibe dois processos de condução, comuns a todas as substâncias. O primeiro, é influenciado pelo nível de hidratação das amostras e está relacionado as moléculas de água distantes das superfícies. O segundo, é próprio da água confinada e possui tempos de relaxação elétricos com transições observadas em -60ºC (210K) na sílica gel, e -45ºC nos outros materiais. Também constatou-se que o tamanho da cadeia polimérica do PVA altera a dinâmica do confinamento de água: cadeias de menor peso molecular não são capazes de gerar sítios que propiciem o confinamento da água. / This work aims to increase the existing knowledge on the dielectric interactions of water confined in hydrophilic materials at low temperatures. The hydrophilic materials (silica gel, gypsum, collagen and polyvinyl alcohol - PVA) were studied with the available functions of Impedance Spectroscopy - dielectric permittivity and electrical impedance. The specific goal of this thesis is to establish the role of hydrogen bonds in the conduction processes observed in confined water and to verify the existence of the supercooled water dynamic crossover at T = -45 ºC (228K). The chosen substances have molecular chains or networks with polar surface groups connected to water molecules through hydrogen bonds. When confined in small geometries, water does not crystallize and can be supercooled bellow its homogeneous nucleation temperature. This allows the indirect investigation of supercooled confined water. The studies of systems involving hydrophilic materials - such as solids, gels and macromolecules - and water, contributes to the development of new materials and to the understanding of living systems. This study demonstrated that the conduction in the confined water occurs through the network formed by hydrogen bonds between water molecules and the chain materials. The impedance spectra of all material exhibits two conduction processes common to all the analyzed samples. While the level of hydration of the samples can influence the process of higher frequencies, the one found in lower frequencies is independent of the amount of water in the samples. The first was associated to bulk water molecules and the second is related to confined water and show the expected dynamic crossover. In addition, the size of the PVA polymeric chain alters the dynamics of water: lower molecular weight polymers are not capable of displaying the supercooled dynamic crossover.

Guidewires have been used in many operating rooms by vascular surgeons to assist them in positioning and maneuvering through a tortuous stenosis or lesion to a desired location, and to be used as a guide for the implantation of a catheter. Surgeons are tasked with having to insert a guidewire inside a small cavity, which requires a high level of skill and patience. The insertion of the guide wire is controlled by a torque device, which allows a surgeon to advance, rotate and grip the wet hydrophilic coating of the guidewire. Despite its many advantages, the torque device does, in fact, give rise to many time consuming issues that results in delays to the surgical procedure. One main problem in the use of the torque device is that it is introduced through the proximal end of the guidewire. Therefore, it requires the assistance of another individual, the surgical technician, to advance the torque device from the furthest point away from the patient. Once the torque device is in position, it is up to the surgeon to attempt to control the tightening, advancing and loosening of the device all with one hand. The other, free hand is used as a placement hand to secure the positioning of the guidewire within the patient. Another issue arises in the removal of the torque device, which must be loosened with one hand and slid off the same end it was introduced, often resulting in the unwanted ejection of the guide wire tip from within the patient's body. The process must then commence from the start, resulting in loss of valuable time, and be repeated until the distal tip of the guidewire is secure in the desired location and the catheter can now be introduced. The main purpose of this research is to investigate, design, and develop a new guidewire torque device to facilitate in a more controlled manipulation of a guidewire by vascular surgeons. Through in-depth interviews with both surgeons and surgical residents alike, direct observational time in the vascular surgery OR (operating room), and I obtained knowledge used as a design basis for the development of the product. For example, observations of relevant medical procedures were also accomplished at Tampa General Hospital to establish a basis for the design,and to assess current vascular surgery medical procedures. Initial design concepts where created using SolidWorks CAD software. After a period of researching and understanding user needs, an assortment of non-slip adhesives where found to be a viable solution to the problem. A characterization analysis was done on the highest rated non-slip adhesive to further define design parameters, and pave the way for FDA approval and product commercialization.

Hydrophilic interaction chromatography is well known as a powerful technique separation of polar and ionizable compound nowadays. However the retention mechanism of the technique is still under debate. Understanding retention mechanism would facilitate the method development using the technique and its future improvement. This was inspiring and became the goal of this thesis. This work involves the characterization of the water enriched layer regarding to water and buffer salt accumulation. Twelve HILIC stationary phase with a diverse surface chemistry regarding to function groups and modification type were studied. Effect of water and salt on regarding to the retention mechanism was investigated by correlating the adsorption data to the retention of selected solutes This also involved the characterization of interactions involve in the separation of 21 HILIC columns. Interactions was probe by retention ratio of pair solutes which are characteristic for each specific interaction. The data was evaluate using principle component analysis – a multivariable data analysis method. The model was comprehensive and its outcomes were confirmed by the studies on adsorptions of water and salts.

This thesis investigates the effect of hydrophilic polymers as novel solid couplants in ultrasonic inspection. These polymers can absorb large quantities of water, thus become soft and flexible, and also adapt themselves very well to applications. In this study, experiments were carried out by preparing three different types of polymer membranes namely [Poly(HEMA), Poly(HEMA-co-GMA), Poly(HEMA-NN&amp / #8242 / -dH2O)] with different thicknesses and monomer contents. Swelling ratios were determined in deionized water using 9mm diameter samples, cut from each polymer. Ultrasonic velocity and sound attenuation measurements were performed with pulse-echo and immersion techniques. These results were analyzed and compared with water, typical plastics and rubbers. In order to evaluate the coupling performance of hydrophilic polymers, weights of 50g, 200g, 500g and 1 kg were used as loading conditions to change the pressure applied to the transducer. Results obtained with this study showed that hydrophilic polymers offer low attenuation at high frequencies and couple effectively while eliminating the risk of test piece contamination. The study also revealed that velocities of polymers decrease by increasing the water content. This research can be used as a guideline for an alternative choice of couplant while testing water sensitive materials in safety critical structures or where the test piece is avoided from contamination and also can be used for rough surfaces.