Citrate-coated gadolinium trifluoride (Cit-GdF3) and poly(acrylic acid)-coated nanoparticles (PAA-GdF3 NPs) were synthesized, the former reproduced from literature (though using more refined conditions), the latter through a new, two-step, ligand exchange method. Diamagnetic nanoparticle analogs (Cit-YF3 NPs) were prepared to investigate citrate interactions with the nanoparticle surface using NMR. Citrate was found to bind in numerous conformations, with a total of between 29 – 46 % bound at 0 ºC. Exchange studies revealed short residence lifetimes of one and twelve seconds respectively for bound and free forms of citrate (0 ºC), perhaps explaining the colloidal instability of these nanoparticles. PAA-GdF3 NPs were synthesized by first producing their Cit-GdF3 counterparts, and then exchanging citrate for PAA. The impetus behind this latter synthesis was the relative enhancement in stability and relaxivity attainable by these nanoparticles. The displacement of citrate by PAA was verified using diffusion NMR studies.

The need and longing to connect to another is a fundamental desire of the human heart, enforcing a sense of movement toward social and personal security and, moreover, the future. Yet it is paradoxical that, where people are the most closely crowded together, feelings of alienation and loneliness are often the greatest. We live in times of busy isolation, on streets where we dont know our neighbours, in societies where our lives are lived behind closed doors. As the global village grows, our personal worlds shrink, both by circumstance and by choice. Our innate, gregarious nature faces its greatest challenge, or ultimate defeat.<p> The story of my hometown, New Waterford, is a substantial element in the story of my life as well as my art. The woodcuts and many of the paintings in the exhibition, Slag, are documentations of this place, its inhabitants and their way of life. It is a town with a unique character resulting from the circumstances surrounding its relationship to coalmininga town that is withering away now that the mines are gone. Other paintings in the exhibition depict people and spaces from other places that I have lived. Though the environments change, there are similarities in the pathos of the human subjects that remain constant. In my work, whether I am depicting the inhabitants of a hollowed out town or the solitary subway commuter, they are united as those things that have been lost or left behind in the name of progressthe leftovers and waste: the slag.

SELF/PORTRAIT is an exploration of the creative process. Based in the genre of portraiture, this collection of work seeks to reveal the ways in which the artist's relationships and circumstances have factored into the creation of the resulting exhibition. This exploration involves the assessment of abandoned projects with the aim of gaining a greater understanding of their qualities that have served to motivate the creation of his art, and those that have hindered his artistic process. This thesis exhibition and support paper use an autobiographical approach to seek the elements of the artist's perception of art which have influenced the production of the work displayed, and how these are effected by the task of creating a Master's thesis exhibition. It explores the qualities of both Portraiture and Painting which have inspired and directed his endeavour. SELF/PORTRAIT seeks to display the artist's work as a process rather than a product.

The need and longing to connect to another is a fundamental desire of the human heart, enforcing a sense of movement toward social and personal security and, moreover, the future. Yet it is paradoxical that, where people are the most closely crowded together, feelings of alienation and loneliness are often the greatest. We live in times of busy isolation, on streets where we dont know our neighbours, in societies where our lives are lived behind closed doors. As the global village grows, our personal worlds shrink, both by circumstance and by choice. Our innate, gregarious nature faces its greatest challenge, or ultimate defeat.<p> The story of my hometown, New Waterford, is a substantial element in the story of my life as well as my art. The woodcuts and many of the paintings in the exhibition, Slag, are documentations of this place, its inhabitants and their way of life. It is a town with a unique character resulting from the circumstances surrounding its relationship to coalmininga town that is withering away now that the mines are gone. Other paintings in the exhibition depict people and spaces from other places that I have lived. Though the environments change, there are similarities in the pathos of the human subjects that remain constant. In my work, whether I am depicting the inhabitants of a hollowed out town or the solitary subway commuter, they are united as those things that have been lost or left behind in the name of progressthe leftovers and waste: the slag.

Surface grafting and modification of poly(acrylic acid) (PAA) were performed on nylon 6,6 carpet fibers to achieve permanent stain and soil resistance. PAA was grafted to nylon and modified with 1H, 1H-pentadecafluorooctyl amine (PDFOA) using an amidation agent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). The first goal was to optimize acrylamide modification of PAA in solution. Aqueous reactions with taurine, hydroxyethyl amine, and butyl amine progressed ~100%, while PDFOA reactions in MeOH progressed ~80%. Reaction products precipitated at 77% butyl or 52% PDFOA acrylamide contents. The second goal was to optimize the PAA grafting process. First, PAA was adsorbed onto nylon 6,6 films. Next, DMTMM initiated grafting of adsorbed PAA. PAA surface coverage was ~78%, determined by contact angle analysis of the top 0.1-1 nm and x-ray photoelectron spectroscopy (XPS) analysis of the top 3-10 nm. The third goal was to modify PAA grafted nylon films with butyl amine and PDFOA. Randomly methylated beta-cyclodextrin (RAMEB) solubilized PDFOA in water. Contact angle detected ~ 100% surface reaction for each amine, while XPS detected ~77% butyl amine (H2O) and ~50% for PDFOA (MeOH or H2O pH=7) reactions. In H2O pH=12, the PDFOA reaction progressed ~89%, perhaps due to greater efficiency, access and solubility. The fourth goal was to perform surface depth profiling via angle-resolved XPS analysis (ARXPS). The PAA surface coverage from contact angle and XPS was confirmed. Further, adsorbed PAA was thicker than grafted PAA, supporting the theory that PAA adsorption occurs in thick layers onto nylon followed by DMTMM-activated spreading and grafting of thinner PAA layers across the surface. The PDFOA reaction in MeOH produced a highly fluorinated but thin exterior and an unreacted PAA interior. The PDFOA reaction in H2O pH=12 produced a completely fluorinated exterior and highly fluorinated interior. Thus surface modification levels from contact angle and XPS were confirmed. The final goal was to PAA-graft and PDFOA-modify nylon 6,6 fabrics and carpets. PDFOA modification achieved significant water and oil repellency. Stainblocking was slightly improved for ionized PAA-g-nylon and greatly improved for PDFOA-modified PAA-g-nylon. However, traditional stainblockers may be necessary to completely prevent dye penetration into carpet tufts.

In this study, pH-sensitive poly(acrylamide-co-acrylic acid) hydrogels were synthesized as controlled release systems in the presence of N,N-methylene bisacrylamide as crosslinker and ammonium persulfate as initiator. A set of hydrogels were used in the form they were prepared. One set of hydrogels were prepared as porous networks by incorporating sodium chloride into the reaction medium and then leaching of it after the completion of polymerization reaction. Two sets of hydrogels were modified by argon-plasma at different discharge powers. Hydrogels were characterized by 13C-NMR, XPS, SEM, ATR-FTIR, ESR as well as equilibrium degree of swelling (EDS) and contact angle measurements. Prepared hydrogels were loaded with a model antibiotic, ciprofloxacin-HCl (CPFX), and in-vitro release of CPFX from hydrogel matrices were examined in buffer solutions of varying pH values. There are two factors determining the release rates of CPFX / one is the pH-dependent solubility of CPFX and the other is EDS of the hydrogel samples. For porous samples drug loading and release rates were higher when compared to the control samples and CPFX solubility dominated over release kinetics. Plasma treatment resulted in prolonged release rates in acidic medium.

Fingernail sculptors may be exposed to ethyl methacrylate and methyl methacrylate in their workplace. The literature suggests that these chemicals may cause sensitization in individuals who are exposed to sufficient quantities. Cases of occupational asthma and allergic contact dermatitis have been reported among persons who work with these chemicals. Little personal exposure data exists on nail technicians' exposures to these chemicals, especially ethyl methacrylate. The literature suggests that the industrial hygiene practices used for methyl methacrylate also be applied to ethyl methacrylate since more is known about methyl methacrylate. Previous exposure studies have revealed relatively low exposures to these chemical. There are no U.S. occupational exposure limits for ethyl methacrylate. The objectives of this study were to measure nail sculptors' exposure to ethyl methacrylate and/or methyl methacrylate vapors in their personal breathing zone, describe the interior lay-out of the nail salon in relation to where the chemical vapors were generated, and quantify the volume of air supplied by the HVAC. This study was designed to further characterize and quantify nail technicians' exposures to ethyl methacrylate and methyl methacrylate. Two nail salons were identified as study sites. A total of five fingernail sculptors volunteered to participate. Personal sampling pumps and activated charcoal media were used to collect organic vapors in the personal breathing zones of the participants. The samples were collected for an entire work shift and analyzed by gas chromatography with dual flame ionization detection, per a modified OSHA 7 Protocol. The 8-hour time weighted averages ranged from <1 - 31 parts per million of ethyl methacrylate and <1 - 5.2 parts per million methyl methacrylate. These levels were similar to those already reported in the literature. These levels were below any U.S. occupational exposure level in place or suggested. Local exhaust ventilation appeared to make a difference, as did natural ventilation. The results of this study strongly suggested that methyl methacrylate was used at one salon despite a ban on its use in nail products.

In this study, waterborne silicone-acrylic resin was produced by incorporating silane coupling agent onto the acrylic main chain by emulsion polymerization. After applying different emulsion polymerization processes, batch polymerization was selected to obtain the resultant resin. Thus finding the optimum conditions by investigating the parameters of monomer ratios, initiators, concentrations of initiators, temperature and time, the novel resin was synthesized. Water-dispersed silicone-acrylic resin was produced using butyl acrylate, butyl methacrylate, methyl methacrylate, 3-methacryloxypropyltrimethoxysilane and acrylic acid as a hydrophilic monomer. 2,2&#039 / -azobis[2-(2-imidazolin-2yl)propane]dihydrogen chloride as thermal initiator and t-butyl hydroperoxide / sodiummetabisulfite as redox couple initiator were selected as the best effective initiators for the production of silicone-acrylic resin. The reaction temperature of the preparation of silicone-acrylic resin was taken as 50&amp / #61616 / C maximum to prevent gelation and agglomeration. To understand the effect of silane coupling agent on the properties of the resin, a new resin was synthesized which did not contain any silane coupling agent and the properties of both resins were determined by FTIR spectroscopy, thermal analysis and mechanical tests. Their physical properties were also determined. The addition of 3-methacryloxypropyltrimethoxysilane to the main chain increased the hardness and the gloss values but slightly decreased the abrasion resistance value of the silicone-acrylic resin. All the samples showed superior flexibility. The produced polymer which contains silane coupling agent showed excellent adhesion properties on glass and metal plates.

Acrylic bone cements are used in dentistry and orthopedic surgery to fix prosthetic devices into the bone. Bone cements transfer and distribute the applied load and increase the load-carrying capacity of the prosthesis/cement/bone system with the help of mechanical bonding between the device and the bone. In spite of all their advantages, bone cements have several drawbacks such as insufficient mechanical properties, high exothermic polymerization temperature, release of monomer to the environmental tissue and loosening of implant. Studies are being carried out to improve bone cement formulations with low curing temperature, good mechanical properties and good biocompatibility. In this study, bone cements with different compositions were prepared by using poly(methyl methacrylate) (PMMA) microspheres, barium sulphate (BaSO4) radiopaque agent, inorganic hydroxyapatite (HA) particles and 1-dodecyl mercaptan (DDM) chain stopping agent. Mechanical and thermal properties of the prepared bone cements were examined. When 8% hydroxyapatite was added into the formulation, both tensile and compressive strengths were increased and curing temperature was decreased. Addition of 13% BaSO4 caused 0.98% and 10.29% decrease in tensile and compressive strength values, respectively. Addition of 1%, 2% and 3% DDM, relative to the amount of methyl methacrylate monomer, decreased the maximum temperature from 101.78&deg / C to 91.80&deg / C, 78.38&deg / C and 71.35&deg / C, respectively. All compositions of the prepared bone cements fulfilled the minimum compressive strength (70 MPa) requirement and the minimum curing temperature was obtained as 71.35&deg / C. In order to have optimum desired properties, further studies to improve biocompatibility, mechanical and thermal properties of bone cements are needed.

Doctor of Philosophy / The kinetics of electrosterically stabilized emulsion systems was studied. The aim of this was to understand the impact that steric and electrosteric stabilizers have on the kinetics of particle growth and particle formation in the area of emulsion polymerization. The well-established mechanisms that govern these processes for emulsions stabilized by conventional low molecular weight surfactants were used as a reference point for comparative purposes. Model latexes were synthesized that comprised of a poly(styrene) core stabilized by a corona of poly(acrylic acid). The advent of successful controlled radical polymerization techniques in heterogeneous media (via RAFT polymerization) allowed for latexes to be synthesized under molecular weight control. For the first time, the degree of polymerization of the stabilizing block on the particle surface was able to be controlled and verified experimentally using mass spectrometry techniques. Three latexes were made with different average degrees of polymerization of the stabilizing block; five, ten and twenty monomer units respectively. A methodology was developed to remove the RAFT functionality from the polymer chains present in the emulsion while retaining the desired particle morphology. Oxidation with tertbutylhydroperoxide (TBHP) was proven to be successful at eliminating the living character provided by the thiocarbonyl end-group. Extensive dialysis and cleaning of the latex was performed to ensure no residual TBHP or reaction by-products remained. Latexes with poly(styrene) cores were chosen for this work as poly(n-butyl acrylate) latexes were shown to be influenced by chain transfer to polymer, providing an additional kinetic complication. The three electrosterically stabilized emulsions were used as seed latexes in carefully designed kinetic experiments to measure the rate of polymerization as a function of time. Two independent techniques (chemically initiated dilatometry and γ-relaxation dilatometry) were used to measure the rate coefficients of radical entry (ρ) and exit (k) in these systems – the two parameters that essentially govern the rate of particle growth. The latexes were chosen such that they satisfied ‘zero-one’ conditions (i.e. that any given latex particle contains at most one growing radical at any given time) in order to simplify data analysis. Three different chemical initiators were used, each yielding a radical with a different electric charge. Results from γ-relaxation experiments demonstrated that the three electrosterically stabilized latexes gave very long relaxation times when removed from the radiation source, ultimately yielding very small k values. These values were up to a factor of 10 smaller than that predicted by the ‘transfer-diffusion’ model for exit for particles of that size. This reduction was attributed to a ‘restricted diffusion’ effect, where the exiting monomeric radical has to diffuse through a dense layer of polymer on the particle surface, where its mobility will be restricted. Modification of the Smoluchowski equation for diffusion-controlled adsorption/desorption to account for this postulate led to the development of a model that gave excellent semi-quantitative agreement with experiment. Chemically initiated dilatometric experiments (using three different types of initiator) gave the unusual result of very low reaction rates and low steady-state values of 'nbar', the average number of radicals per particle. Using the standard kinetic equations for styrene-based systems (where it is assumed that an exited monomeric radical undergoes re-entry), this led to the calculation of impossibly small values of the entry rate coefficient ρ (far below any background or ‘thermal’polymerization rate). However upon removing the assumption of re-entry and assuming that exited radicals undergo termination, the obtained values of ρ were in almost perfect agreement with the values predicted from the ‘control by aqueous phase growth’ entry mechanism. This unexpected result was attributed to chemical reaction with the poly(acrylic acid) stabilizers through chain transfer to polymer (via hydrogen-atom abstraction). This postulate was verified by separate experiments that demonstrated that poly(acrylic acid) could act as a reasonably efficient chain transfer agent for styrene polymerization. The addition of poly(acrylic acid) to the aqueous phase of a conventionally stabilized emulsion also led to the rate reduction seen previously. NMR experiments demonstrated the existence of poly(acrylic acid-graft-styrene), which could only be formed through termination of a poly(styrene) chain with a poly(acrylic acid) chain bearing a mid-chain radical (as the product of a chain transfer reaction). These additional terms of transfer and termination were included in the governing kinetic equations of emulsion systems (the Smith-Ewart equations) to develop a model to account for the behaviour of electrosterically stabilized latexes. The ultimate fate of an exiting radical was now shown to be a competition between fates; successful desorption into the aqueous phase, or chemical reaction (through transfer or termination) within the hairy layer. These additional terms were shown to significantly reduce the theoretical value of nbar, and were in excellent agreement with experiment. For small electrosterically stabilized particles with a densely packed ‘hairy layer,’ it was seen that transfer/termination is the dominant loss mechanism as opposed to desorption. The developed model showed that as the particle size was increased, the dominant loss mechanism once again became successful desorption into the aqueous phase. The model was shown to give excellent agreement with experimental data from ‘uncontrolled’ emulsion systems. To explain the highly unusual secondary nucleation behaviour seen in systems such as these, it was postulated that beta-scission of a poly(acrylic acid) chain bearing a mid-chain radical is an important mechanistic step in the nucleation mechanisms of these systems. Modelling (both steady-state and time-dependent) gave good agreement with experiment with a minimal number of adjustable parameters. Theory (and supporting experimental evidence) demonstrated that this nucleation mechanism is only significant at high particle numbers; under other conditions the well-known ‘homogeneous nucleation’ mechanism is once again dominant.