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APPROACHES TO MOLECULAR IMPRINTING ON POLYSILOXANE SCAFFOLDSBrown, Michael Edward 01 January 2007 (has links)
Molecular imprinting, a common method used in separations and chromatography to isolate specific molecules via surface binding, has been adapted for applications in biomaterials and related sciences. The objective of this study was to determine the effectiveness of different approaches to molecular imprinting by testing for preferential binding of protein on polysiloxane scaffold surfaces. To test preferential rebinding, the scaffolds were exposed to a mixture of the template protein and a competitor protein with similar size but different chemistry. Lysozyme-imprinted polymers rebound 8.13 0.99% of lysozyme without any competition and 5.1 0.3% of the protein during competition. Lysozyme C peptide was imprinted into polysiloxane scaffolds to investigate the epitope approach to molecular imprinting. Without competition, 8.95 11.53% of the lysozyme preferentially bound to the scaffolds, while under competition 1.85 9.47% bound to the scaffolds. Lastly, bone morphogenetic protein 2 (BMP-2) was imprinted into the polymer scaffolds. Results revealed that BMP-2 imprinted scaffolds bound 10.09 6.625% under noncompetitive conditions and a very small 0.65 4.55% during competition. Trends of preferential binding via peptide imprinting and BMP-2 imprinting can be seen, and show promise in future tissue engineering material applications and biomaterial compatibility.
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Silica Sol Gel Bulk Gelation in Various Gravity RegimesPienaar, Christine Louise Unknown Date (has links)
Nanomaterials are currently attracting billions of dollars in research funding and are entering such diverse fields as the computing, communications, life science and energy sectors. The growing popularity of nanomaterials demands a comprehensive understanding of the means by which such materials can be produced including the effects of physical and chemical factors. One method of forming inorganic nanomaterials is the sol-gel process; a low temperature process combining the benefits of glass and plastics technology. Whilst the research community has ascertained that gravity is important and appears to affect the sol-gel process, no coherent picture of the role of gravity on the sol-gel process has been proposed. The flexibility of the sol-gel process, and the promise it holds for creating products as diverse as hydrogen fuel cell membranes through to protective coatings for space vehicles, make it an important area of study. This thesis addressed a fundamental gap in the scientific knowledge concerned with the sol-gel process: how and why does gravity affect the sol-gel process? The nanomaterial chosen for study was a xerogel, a dense compound with a high surface area which finds applications in high temperature ceramics, energy saving coatings, molecular filtration and thin film sensors. The xerogel was produced from an acid catalysed sol. 2ml samples of the sol were subjected to reduced, normal and high gravity levels, and the resultant xerogels were characterised through liquid and solid state NMR and nitrogen adsorption/desorption techniques. Viscosity and pH measurements were also recorded. Reduced gravity conditions were provided by NASAs KC-135 aircraft which is capable of creating a 25 second window of 1x10−2 gravities. A centrifuge was utilised to simulate increased gravity environments and xerogels were formed between 2 and 70 gravities. Analysis of the results led to two major contributions to this field of scientific endeavour. It was concluded that (1) gravity affected the reaction pathways of the sol-gel process and (2) gravity directly altered the molecular structure of xerogels The second contribution was determined through the NMR studies, where it was shown that a reduction in gravity resulted in a molecular structure composed of extended branches of cyclic compounds. Due to a decrease in convection in reduced gravity the molecular structure of the sample was dominated by cyclisation. In terrestrial and high gravity the molecular structure grew through both bimolecularisation and cyclisation reactions. Thus the gravity level also determined the reaction pathway available within the sol by creating a more or less convective environment. This created a structure composed of cyclics (rings) and chains. As gelation and drying of the sol occurred there was a loss in Q4 group amount. Chains, having a higher energy configuration than rings, underwent repolymerisation. Short chains formed which reacted end-to-end to form small, stable rings. The rings packed together more closely within the liquid sol and delayed the formation of a spanning cluster. The greater the gravity level, the greater the extent of bimolecularisation reactions contributing to chain formation, in turn allowing a greater degree of repolymerisation of the molecular structure. Thus gel times increased as the gravity level increased. Again gravity directly affected the reaction pathway of the sol-gel process. In reduced gravity the sol gelled very quickly due to the formation of a cyclic structure which was not capable of repolymerisation. The final contribution of this thesis was the proposal of a mechanistic model. The model depicted the ffect of gravity on the formation of the molecular structure of a xerogel.
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Charakterisierung von PZT-Dünnschichten auf MetallsubstratenDutschke, Anke. Unknown Date (has links) (PDF)
Würzburg, Universiẗat, Diss., 2008.
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Development of a self-healing corrosion protection coating system for high strength aluminium alloys /Raps, Dominik. January 2008 (has links)
Zugl.: München, Techn. University, Diss., 2008.
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Development and characterisation of liquid impact resistant sol-gel coatingsGrundwürmer, Matthias January 2008 (has links)
Zugl.: München, Techn. Univ., Diss., 2008
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Erhöhung der Steinschlagfestigkeit von PressglasŞerban, Corina Ioana January 2008 (has links)
Zugl.: Clausthal, Techn. Univ., Diss., 2008
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Direkte Sol-Gel-Synthese komplexer Al-basierter Metallfluoride des Tetra- und Hexafluoroaluminat-Typs strukturelle Charakterisierung und Erschliessung möglicher AnwendungsgebieteAhrens, Mike January 2008 (has links)
Zugl.: Berlin, Humboldt-Univ., Diss., 2008
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Development and characterisation of liquid impact resistant sol-gel coatings /Grundwürmer, Matthias. January 2008 (has links)
München, Techn. University, Diss., 2008.
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Switching hybrid polymers with physically and covalently entrapped organic photochromesKlukowska, Anna. Unknown Date (has links) (PDF)
University, Diss., 2005--Würzburg. / Erscheinungsjahr an der Haupttitelstelle: 2004.
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Chemische Sensorik mit neuen Beschichtungen für die FlüssigphaseKaspar, Michael. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2000--Tübingen.
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