Dissertations / Theses on the topic 'Titania surface'
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Papageorgiou, Anthoula Chrysa. "Surface studies of titania related nanostructures." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445001/.
Full textRagazzon, Davide. "Titania Nanoscale Films and Surfaces : Surface Science Investigation of Structure and Properties." Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-224124.
Full textRudkin, Christopher Julian. "Surface organometallic chemistry of rhodium and palladium on titania." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242666.
Full textStone, Peter John. "STM studies of the structure and reactivity of oxide surfaces and model catalysts." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340075.
Full textBurnaby, Daryl. "The surface organometallic chemistry of rhodium and palladium supported on inorganic oxides." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327360.
Full textTorun, Engin. "Electronic Properties Of Dye Molecules Adsorbed On Anatase-titania Surface For Solar Cell Applications." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610846/index.pdf.
Full textJensen, Stephen C. "The Role of Interstitials and Surface Defects on Oxidation and Reduction Reactions on Titania." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10768.
Full textChemistry and Chemical Biology
Yetisemiyen, Pelin. "Low Temperature Photocatalytic Oxidation Of Carbon Monoxide Over Palladium Doped Titania Catalysts." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612466/index.pdf.
Full textMarszewski, Michal. "Development of highly porous crystalline titania photocatalysts." Kent State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1476281107453411.
Full textWang, Xiaodan [Verfasser]. "Tuning the Photoelectrochemical Functionality of CoreShell H-doped Titania Nanorods by Hydrogen Surface Engineering / Xiaodan Wang." München : Verlag Dr. Hut, 2018. http://d-nb.info/116125045X/34.
Full textKorkmaz, Erdural Beril. "Photocatalytic Antimicrobial And Self-cleaning Properties Of Titania-silica Mixed Oxide Thin Films." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615137/index.pdf.
Full textCinar, Merve. "Enzyme Immobilization On Titania-silica-gold Thin Films For Biosensor Applications And Photocatalytic Enzyme Removal For Surface Patterning." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12611021/index.pdf.
Full textg/ml and 12 hours respectively. The resulting invertase immobilized thin films showed high storage stability retaining more that 50% of their initial activity after 9 weeks of storage. Photocatalytic enzyme removal and re-immobilization studies were carried out by irradiating the invertase immobilized thin films with blacklight. Upon 30 minutes of irradiation, immobilized invertase was completely and irreversibly inactivated. Initial immobilized invertase activity (before the irradiation) was attained when invertase was re-immobilized on thin films that were irradiated for 5 hours. Thus it was inferred that with sufficient exposure, enzymes can be completely removed from the surfaces which makes the re-immobilization possible. The possibility of enzyme removal with photocatalytic activity and re-immobilization can pave the way to new patterning techniques to produce multi-enzyme electrode arrays.
Saito, Toshihiko. "Effect of titania-based surface modification of polyethylene terephthalate on bone-implant bonding and peri-implant tissue reaction." Kyoto University, 2011. http://hdl.handle.net/2433/142081.
Full textDodekatos, Georgios [Verfasser], Harun [Gutachter] Tüysüz, and Ferdi [Gutachter] Schüth. "Copper-cobalt-based catalysts and gold/titania nanostructures for thermocatalytic and surface plasmon-assisted glycerol oxidation / Georgios Dodekatos ; Gutachter: Harun Tüysüz, Ferdi Schüth." Bochum : Ruhr-Universität Bochum, 2017. http://d-nb.info/1144613639/34.
Full textWeatherspoon, Michael Raymond. "Conformal sol-gel coatings on three-dimensional nanostructured templates." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/28157.
Full textCommittee Chair: Sandhage, Kenneth; Committee Member: Barefield, Kent; Committee Member: Bunz, Uwe; Committee Member: Carter, Brent; Committee Member: Tannenbaum, Rina.
Alhendal, Abdullah Awadh. "Hydrolytic and Nonhydrolytic Sol-gel Zirconia-, Titania-, and Niobia-based Capillary Microextraction Coatings for the Preconcentration and HPLC Analysis of Catecholamine Neurotransmitters and Phosphorylated Peptides." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6452.
Full textSegro, Scott S. "Surface-Bonded Sol-Gel Sorbents for On-Line Hyphenation of Capillary Microextraction with High-Performance Liquid Chromatography." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1762.
Full textPlaisance, Marc Charles. "Cellular Response to Surface Wettability Gradient on Microtextured Surfaces." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/53730.
Full textFaure, Bertrand. "Particle interactions at the nanoscale : From colloidal processing to self-assembled arrays." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-79129.
Full textAt the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.
Fabre, Héloïse. "Contributions des propriétés physico-chimiques de surfaces de titane sur l'adhérence de microorganismes : application aux chambres implantables." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1023/document.
Full textTotally implantable venous-access ports are medical devices used for the administration of chemotherapy drugs and/or parenteral nutrition. Infections can occur and it is indispensable in modern-day medical practice to prevent and reduce the rare infectious complications. In this context, the goal of this work was to study the contribution of the modification of physico-chemical properties of titanium based surfaces on the adherence of microorganisms. Surfaces with different characteristics were produced and the adherence of the bacterium Staphylococcus aureus and the yeast Candida albicans was studied in vitro in static conditions. Model surfaces made of titanium dioxide with roughness from nanometer to micrometer were elaborated using silicon wafers recovered with a thin film of titanium dioxide deposited by plasma vapor deposition. Titanium alloy surfaces (Ti grade 2 and Ti grade 5) were modified by polishing, grit-blasting or wire erosion, to create different surface morphologies. In vitro studies were performed and it was found that the number of adhering microorganisms changed with roughness, but more importantly with the surface morphology of the biomaterials and microorganisms size. Flat titanium dioxide thin films were then functionalized by molecular grafting to modify the hydrophobicity of the surface. Study of plasma protein adsorption, by QCM, allowed to better explain the adherence of bacteria and yeast onto these surfaces. The influence of parenteral nutrition and chemotherapy drugs was also studied in order to better approach the real conditions of totally implantable venous-access ports
Harte, Sean Paul. "Surface EXAFS studies of chromium and titanium upon #alpha#-quartz (0001) surfaces." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263901.
Full textRick, Helene Sylvia. "Nanocarving of Titania Surfaces Using Hydrogen Bearing Gases." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7116.
Full textPark, Jung Hwa. "The role of surface chemistry and wettability of microtextured titanium surfaces in osteoblast differentiation." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44732.
Full textSisti, Karin Ellen [UNESP]. "Análise da superfície de titânio sob ação do laser com e sem deposição de hidroxiapatita." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/93591.
Full textUniversidade Estadual Paulista (UNESP)
O longo tempo de espera entre a cirurgia e a instalação da prótese sobre implante dentário, sempre preocupou os pesquisadores. Proposição: Estudar a superfície de implantes utilizando discos de titânio irradiados com feixe de laser. Método: A amostra foi irradiada com feixes de laser de alta intensidade (Nd-YAG), posteriormente depositado hidróxiapatita e submetido a tratamento térmico. Foi analisada sob MEV (Microscópio Eletrônico de Varredura) e realizada análise morfológica qualitativa com microfotografias em vários aumentos. Resultados: A superfície irradiada com laser apresentou deformidade superficial e característica isomórfica; a aplicação de hidroxiapatita pelo método de biomimético aumentou quantitativamente a área da superfície de titânio; a amostra demonstrou características não encontradas nos implantes disposto no mercado. Conclusões: deposição de hidroxiapatita, melhor característica isomórfica e aumento quantitativo da área superficial estudada.
Background: Delay between surgery and dentistry prosthesis is the important factory to studier. Proposition: The aim of this study has been to analyze the surface of titanium implants in the odontology. Methods: Titanium discs were treated with laser high insensitive (Nd-YAG), and deposited hydroxyapatite with thermal treatment. Sample received Morphological analyze qualitative for micrographies with many size in SEM (Scanning Electron Microscopy). Results: Surface laser irradiation shows roughness and isomorphic characteristic. The hydroxyapatite amplified the titanium surface area by method bio mimetic. Sample shows characteristics don t have in the market. Conclusions: The treatment surface showed hydroxyapatite, good isomorphic characteristic, amplification the titanium surface area.
Zhao, Xun. "Effect of Surface Wettability, Morphology and Chemistry on the Biocompatibility of Laser Textured Titanium Surfaces." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42254.
Full textBrown, Jacob Leslie. "Vapour-liquid equilibria within nanoporous media." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277690.
Full textFang, Lin. "Surface Engineering of Mesoporous Silica for Ti-Based Epoxidation Catalysts." Thesis, Lyon, École normale supérieure, 2012. http://www.theses.fr/2012ENSL0761/document.
Full textThe active sites for epoxydation of alkenes in silica supported titanium catalysts are isolated Ti(IV) ions. The strategy for site isolation consists here to graft titanium isopropoxyde by reaction with surface silanol groups, the density of which is decreased by chemical capping instead of the energy consuming thermal treatment. The molecular stencil patterning technique (MSP) is applied to enforce site isolation. In mesostructured porous silicas, the partly extracted templating surfactant plays the role of a MSP mask during capping. Then, the elimination of the remaining surfactant liberates silanol islands for the grafting of Ti(IV) ions. Quantitative FT-IR and 29Si MAS-NMR studies reveal that the inverse organic stencil made of grafted organosilyls groups is maintained at each synthesis steps. Diffuse reflectance UV spectroscopy in correlation with the catalytic activity in epoxidation of cyclohexene show that these original surfaces favor the formation of a much larger number of isolated mononuclear sites than the unmodified silica surfaces. The demonstration is obtained using a dipodal organosilyl function, 1-2-ethanebis (dimethylsilyl) (EBDMS) that is much more stable than the classic and monopodal, trimethylsilyl (TMS). Besides, it is shown that the inverse organic stencil (from EBDMS or TMS) is stabilized further by thermal treatment while its dispersive effect on titanium can be preserved. The proof relies on a quantitative 29Si solid State NMR study. Finally, a refined description of the grafting mode of titanium was realized by simulation of the UV spectra of a large series of catalysts assuming only 5 different types of species including isolated species and clusters differentiated by the range of sizes
Lemmon, Mark Thomas. "Properties of Titan's haze and surface." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186927.
Full textBrowne, Martin. "Surface modification of titanium alloy implants." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262067.
Full textSzczepankiewicz, Steven Henry Hoffmann Michael R. "Surface chemistry of titanium dioxide photocatalysts /." Diss., Pasadena, Calif. : California Institute of Technology, 2001. http://resolver.caltech.edu/CaltechETD:etd-05232006-094537.
Full textCamagu, Sigqibo Templeton. "Surface modification of titanium-based alloys." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/4967.
Full textTwo routes of Oxygen Diffusion Hardening (ODH) have been investigated on two alloys of titanium, Ti-6AI-4V and Ti-6AI-7Nb (by weight). The first route involves a controlled atmosphere where argon saturated with water was used to transport water into the test pieces at elevated temperatures. The controlled atmosphere would encourage the generation of mono-atomic oxygen through the dissociation of water vapour, and therefore change the kinetics of physical absorption and diffusion of oxygen into titanium. The second route of ODH investigated was the Oxygen Boost Diffusion Hardening (OBDH). The oxygen boost diffusion hardening process was carried out in two steps. The first step was oxidation of the samples in air at elevated temperatures and the second step was to further diffusion treat the pre-oxidised test pieces III a vacuum or argon. Various temperature and time combinations were used on both steps of OBDH.The results revealed that the ODH heat-treatment in a controlled saturated argon environment was unsuccessful in developing a significant oxygen diffusion hardened layer. The OBDH process can be carried out to modify the surface properties of titanium and alloys. Both steps of this process play a vital role in achieving a thick modified layer for improved tribological properties of titanium and alloys. Performing the oxidation step of OBDH heat-treatment at higher temperatures results in higher surface hardness and deeper diffusion zone than carrying the oxidation step at lower temperatures for longer times provided there is no peeling of the oxide scale during the high temperature oxidation. The Ti-6AI-4V achieves higher surface hardness than the Ti-6AI-7Nb upon the same OBDH heat-treatment. The second step of the OBDH can also be carried out in an argon environment instead of vacuum. Carrying out the second step in an argon atmosphere allowed for higher surface hardness and thicker hardened zone than carrying the same step in vacuum. The effect of the OBDH on the underlying microstructures of two alloys under investigation is the depletion of the ɑ phase on the modified surface as a result of the diffused oxygen which stabilises the ɑ phase. Although higher surface hardness was achieved for the Ti-6AI-4V alloy than the Ti-6AI-7Nb alloy after the same heat treatment, the Ti-6AI-7Nb alloy achieved higher wear resistance due to more adherence of the oxide scale after the oxidation step. Despite achieving higher surface hardness and thicker hardened zone upon carrying out the second step of OBDH in an argon atmosphere than in vacuum, samples which underwent the second step of OBDH heat-treatment in vacuum exhibited higher wear resistance. Performing a twin cycle OBDH heat-treatment results in even higher surface hardness and higher wear resistance despite the severe scaling of the alloys upon the heat treatments.
Cridling, Quentin. "Influence of the substrate surface on optical properties and color of anodized titanium." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEM015.
Full textThe study and the development of goniochromic materials remains a challenge both for industry and for scientific research. In the industry, the color quality control is rendered difficult by the complex color effects of these materials. The development of standard goniochromic materials with referenced color effects could simplify this color quality control. By comparing the manufactured materials to the reference ones by for example acquiring pictures of both materials in given geometries could be an easy process for color quality control. The challenge for scientific research consists to be able to control the color evolution with the illumination and observation conditions and define color characterization geometries in agreement with perceived color effects. A bibliographic review showed that anodized titanium is a promising candidate for reference goniochromic samples. In order to obtain samples with different levels of gloss, samples with substrate roughnesses ranging from a few to two hundred nanometers obtained through hydrofluoric etching or different mechanical and chemical polishing were prepared. Anodized titanium color is linked to the oxide layer thickness and the material refractive index. These parameters were estimated through different techniques in particular a technique based on the extrema of the material reflectance spectrum as well as ellipsometry and X-ray reflectometry. These parameters were put into an optical model in order to simulate the material specular reflectance. The diffuse and specular reflectances of the samples are also compared and a first simple model of the diffuse reflectance is presented. The Bidirectional Reflectance Distribution Function (BRDF) spectral and angular variations are used to characterize the diffuse appearance and goniochromism of the samples versus the substrate preparation and the anodizing cell potential
Seel, Jennifer A. "Ion-surface scattering measurements of the (110) surface of titanium dioxide." Thesis, University of Ottawa (Canada), 1997. http://hdl.handle.net/10393/4149.
Full textJanzeer, Yasmeen. "Surface modification of titanium and titanium alloys to enhance bone healing." Thesis, King's College London (University of London), 2013. https://kclpure.kcl.ac.uk/portal/en/theses/surface-modification-of-titanium-and-titanium-alloys-to-enhance-bone-healing(04574a0c-b593-47ef-a002-608cbe67a04b).html.
Full textPegueroles, Neyra Marta. "Interactions between titanium surfaces and biological components." Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/6066.
Full textEl objetivo de esta tesis doctoral es profundizar en el conocimiento de las interacciones material-biosistema, con el énfasis en el descubrimiento de relaciones entre las propiedades superficiales de las superficies de titanio y su respuesta biológica in vitro.
El titanio comercialmente puro (Ti c.p.) está siendo ampliamente utilizado con éxito durante muchos años como biomaterial para implantes en cirugía ósea. Su excelente biocompatibilidad se basa en sus adecuadas propiedades mecánicas y, con mayor importancia, en su excelente resistencia a la corrosión. Esta última se debe principalmente a la formación espontanea de una fina película de óxido de titanio que le confiere protección natural contra los ataques degradativos. La modificación de la topografía de la superficie del titanio ha sido objeto de investigación en el pasado con el fin de mejorar la osteointegración. El granallado de partículas es una de las tecnologías más utilizadas para conferir rugosidad a las superficies del titanio. La rugosidad óptima y el tipo de partículas abrasivas del granallado para una respuesta óptima in vitro e in vivo fue previamente determinada en nuestro laboratorio. Sin embargo, todavía están por determinar cuáles son las causas últimas que llevan al biomaterial a su exitosa respuesta biológica.
En este trabajo se han estudiado superficies pulidas y rugosas de Ti c.p. obtenidas mediante el granallado con partículas abrasivas de diferente composición química(Al2O3 y SiC) y diferentes tamaños (212-300μm; 425-600μm; 1000-1400μm). La completa caracterización de las propiedades física y química de la superficie, incluyendo la rugosidad, la composición química, la mojabilidad/energía libre y la carga eléctrica de las superficies ensayadas ha llevado a una serie de relevantes conclusiones. Entre ellas, cabe destacar que a) la composición química de las partículas de granallado, así como el método de esterilización fueron los principales factores que influyeron en la mojabilidad y la energía libre superficial de las superficies de titanio estudiadas, b) el método de esterilización cambió en la energía superficial el carácter de donante de electrones de las superficies mediante el cambio de la cantidad y la naturaleza de las sustancias adsorbidas, y c) la composición química de las partículas de granallado no influyó en la carga eléctrica a pH fisiológico ni en el punto isoeléctrico de las superficies.
Un segundo paso consistió en el uso de una microbalanza de cristal de cuarzo con monitorización de la energía de disipación, para el estudio de la cinética de adsorción (cantidad y conformación) y de los procesos de adsorción competitiva de tres proteínas de especial interés en los procesos de curación del hueso - la albúmina de suero bovino (BSA), el fibrinógeno (Fbg), y la fibronectina (Fn)- en sensores lisos recubiertos de TiO2. Se determinaron diferentes modelos de procesos de adsorción con una, dos o múltiples pasos distinguibles en función de las proteínas en solución. La capa adsorbida de BSA mostró los cambios más significativos en sus propiedades mecánicas, de conformación y de incorporación de agua hasta que se alcanzaron las condiciones estables de adsorción de proteínas. La BSA, la más pequeña de las proteínas ensayadas, desplazó la Fn y el Fbg cuando se ensayó en condiciones de la competencia por la adsorción, indicando su mayor afinidad por las superficies de TiO2. También se emplearon técnicas de marcaje fluorescente para el estudio de la adsorción proteica en superficies rugosas granalladas. En este estudio, por un parte, se pudo determinar que la cantidad de Fn y BSA adsorbidas en las superficies granalladas está directamente correlacionada con su energía superficial. Por otra parte, se visualizó la adsorción de fibronectina en solución sobre muestras granalladas rugosas de Ti. La Fn formó un patrón irregular de adsorción con una mayor cantidad de proteína adsorbida en los picos que en los valles de la topografía.
También se evaluó la organización espacial de la matriz extracelular de los osteoblastos, ECM, sobre superficies de Ti lisas y rugosas por medio de la visualización de las fibrillas de Fn teñidas con marcador fluorescente. Las células osteoblásticas depositaron las fibrillas de Fn con un determinado patrón organizado dentro de la matriz total secretada. Aparecen como una película que cubre la parte superior de las diferentes superficies rugosas de titanio. Un resultado relevante es que el espesor de esta capa aumentó con la rugosidad de la topografía subyacente. Sin embargo no más de la mitad de la máxima distancia pico-valle se cubrió con la proteína secretada y/o reorganizada.
Por último, teniendo en cuenta las diferencias en la organización de la ECM y la
adsorción de Fn en las superficies ensayadas de Ti, se realizó un estudio de qRT-PCR para determinar la influencia de las propiedades superficiales del titanio, con y sin preadsorción de Fn, en la respuesta osteoblástica. La expresión génica de la subunidad 5 de la integrina celular, como marcador de la adhesión celular, se incrementó en las superficies granalladas con SiC en comparación con las granalladas con alúmina. Este resultado fue correlacionado con la mayor cantidad de Fn adsorbida debido a la mayor energía superficial de las superficies granalladas con SiC. El aumento de la rugosidad, así como la presencia de partículas de alúmina en las superficies rugosas incrementó la actividad de ALP y la expresión génica de ALP mRNA por los osteoblastos, y por lo tanto su diferenciación.
The understanding of cell/protein/biomaterial interactions is critical to the engineering of substrates for numerous biomedical and biotechnological applications and to the clinical success of implants. The final biological response induced by implants is strongly influenced by the biological-components/synthetic-material surface interactions. It is well accepted that the physical and chemical surface properties of a biomaterial rather than its bulk properties will influence the protein adlayer and then the cell response to it, both in vitro and in vivo.
The aim of this PhD thesis is to gain an increased understanding of the materialbiosystem interactions, with an emphasis on establishing correlations between surface properties of titanium surfaces and its in vitro biological response.
Commercially pure titanium (c.p. Ti) is being widely and successfully used implant biomaterial in bone surgery over many years. Its excellent biocompatibility is based in its appropriate mechanical properties and, more importantly, in its excellent corrosion resistance, which is mainly due to the presence of a naturally-occurring thin protective titanium oxide film. Modification of titanium surface topography has been a subject of research in the past with the purpose of improving its osseointegration. Grit blasting is one of the most used technologies to roughen titanium surfaces for this purpose. The optimal roughness and type of abrasive blasting-particles for a better in vitro and in vivo response was previously determined in our lab. However, which and how different relevant surface properties of the blasted titanium surfaces induce that optimal biological behavior is still poorly understood.
Smooth/polished and rough c.p. Ti surfaces obtained by blasting with abrasive
particles of different chemical composition (Al2O3 and SiC) and different sizes (212-300μm; 425-600μm; 1000-1400μm) were studied. The comprehensive characterization of physical and chemical surface properties, including roughness, chemical composition, wettability/free energy and electrical charge of the tested surfaces led to a series of relevant conclusions. Among them, it is worth noting that a) the chemical composition of the grit-blasting particles as well as the method of sterilization were found the main factors influencing wettability and surface free energy of the titanium surfaces; b) the sterilization method changed the electron donor character of the surfaces by changing the amount/nature of physisorbed substances on the surfaces, and c) the chemical composition of the blasting particles did not influence on the electrical charge at physiological pH and the isoelectric point of the surfaces.
A second step consisted in the use of a quartz crystal microbalance with monitoring of the energy dissipation to study the adsorption kinetics (amount and conformation) and adsorption competition processes of three proteins of special interest in the healing processes of bone -bovine serum albumin (BSA), fibrinogen (Fbg), and fibronectin (Fn)-on smooth TiO2-coated sensors. Different patterns of adsorption with processes in one, two or multiple distinguishable steps were determined depending of the protein in solution. The BSA adlayers showed the most significant changes in their mechanical properties/conformation/incorporation of water until steady protein-adsorption conditions were reached. BSA, the smallest of the tested proteins, displaced Fn and Fbg when in competition for adsorption, which is an indication of its higher affinity for TiO2 surfaces. Fluorescent labelling techniques where used to study protein adsorption on blasted rough surfaces. Most significantly, the amount of Fn and BSA adsorbed on blasted surfaces was positively correlated with their surface energy. The adsorption of fibronectin from solution on shot-blasted rough titanium surfaces resulted in an irregular pattern of adsorption with a higher amount of protein adsorbed on peaks than on valleys of the topography.
Further, the spatial organization of the osteoblast extracellular matrix, ECM, on smooth and rough Ti surfaces was evaluated by visualizing fluorescently-stained Fn-fibrils. Osteoblast-like cells deposited Fn- fibrils in a specific facet-like pattern that was organized within the secreted total matrix. It appeared as a film overlying the top of the different rough titanium surfaces. Interestingly, the thickness of this layer increased with the roughness of the underlying topography, but no more than half of the total maximum peak-to-alley distance was covered.
Finally, taking into consideration the differences in ECM organization and Fn adsorption on the tested Ti surfaces a qRT-PCR study was carried out to elucidate the influence of titanium surface properties with and without Fn-precoatings on the osteoblast response. The expression of 5 integrin subunit gene, as a marker for cell adhesion, was increased in SiC-blasted surfaces compared to alumina-blasted surfaces. This was related to the higher amount of adhesive-protein Fn adsorbed caused by the higher surface energy of SiC-blasted surfaces. The increase of roughness as well as the presence of alumina particles on blasted surfaces increased ALP activity and ALP mRNA gene expression by osteoblasts, and so their differentiation.
This research work contribute to increase our knowledge on the interactions taking place at the bio/non-bio interface between different biological components -water, proteins, cells- and materials of clinical relevance, such as rough titanium. The
intertwined effects of the different properties of the synthetic surfaces appear as a challenge to unravel the ultimate causes that determine the fate of cells on synthetic biomaterials.
Skelton, Adam. "Modelling the interaction between titania surfaces and strong-binding peptides." Thesis, University of Warwick, 2008. http://wrap.warwick.ac.uk/93410/.
Full textSharma, Priyanka. "Investigations of Titan's Topography and Surface Roughness." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/241978.
Full textKashani, Bozorg Seyed Farshid. "Laser surface modification of titanium aluminide alloys." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243450.
Full textRezai-Tabrizi. "Surface treatments of titanium and its alloys." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338082.
Full textCheerkapally, Raghavender P. "Surface-induced structural transformations in titanium nanowires." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384869599.
Full textLorenz, R. D. "Exploring the surface of Titan." Thesis, University of Kent, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387020.
Full textSun, Tao, and 孙韬. "Surface modification of titanium metal for medical applications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45457694.
Full textLu, Xiong. "Engineering titanium surfaces for improving osteointegration /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?MECH%202004%20LU.
Full textBrunot-Gohin, Céline. "Optimisation des états de surface du titane et des alliages en nickel-titane par des films multicouches de polyélectrolytes." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00771411.
Full textGharbi, Myriam. "Etats de surface de pièces métalliques obtenues en Fabrication Directe par Projection Laser (FDPL) : compréhension physique et voies d’amélioration." Thesis, Paris, ENSAM, 2013. http://www.theses.fr/2013ENAM0026/document.
Full textThe process of direct manufacturing by projection laser ( FDPL), is a process of additive manufacturing which allows to make rooms(parts,plays) of complex shape directly from a file CAD, without tool and without mold(mussel). One of its major inconveniences is the bad quality of the states of surface obtained (Ra upper to 15 µm) which requires systematically stages of remanufacturing. In this context, and within the framework of the project ANR " aspect ", this thesis(theory) has for double objective a better understanding of the origin of the degraded states of surface, and the development of various innovative experimental solutions allowing to improve the states of surface. At first, by considering simple geometries (walls) in alloy of titanium Ti-6Al-4V, we studied the interaction
Abdullah, Hasan Zuhudi Materials Science & Engineering Faculty of Science UNSW. "Titanium surface modification by oxidation for biomedical application." Awarded By:University of New South Wales. Materials Science & Engineering, 2010. http://handle.unsw.edu.au/1959.4/44718.
Full textDuncan, Morris. "Surface and sensor studies of doped titanium dioxide." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365772.
Full textKroger, Emily Alice. "Surface Structural Studies of Titanium and Vanadium Oxides." Thesis, University of Warwick, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487941.
Full textFolkes, Janet Ann. "Laser surface melting and alloying of titanium alloys." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38315.
Full textDufrenoy, Stephane. "Influence des transformations surfaciques induites par traitements thermomécaniques sur la tenue en fatigue du Ti-10V-2Fe-3Al." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCD064/document.
Full textTitanium alloys are widely used in aeronautics industries. However, these alloys are highlysensitive to the method for elaboration and transformation processes. These processesimpact on the surface integrity of products. Therefore, they have to be controlled inorder to predict life time of structures.In this work, the study of surface integrity is focused on the description of microstructalevolution, residual stresses and micro-geometry. Four points bending tests were performedin order to determined the fatigue limit of the different studied processes. We find outa good consistency between models used to determinate lifetime from surface integrityinvestigation and experimental results.Moreover, microstructures of titanium alloys are highly complex and they often are twophasedmaterials. Consequently, we studied the heterogeneous behaviour of such materialby X-ray diffraction investigation.We found out that these heterogeneities have an impacton residual stresses determination. Therefore, a non-standard methodology was definedand validate by simulation using a micro-mechanic model : a self-consistent model.Micro-mechanical models are interesting for the residual stresses determination using Xraydiffraction because they allow to take into account heterogeneous and anisotropicbehaviours through anisotropic elasticity and anisotropic texture