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Synthesis of ceramic powder materials in the presence of the ultrasound field
Kočicová, Pavla ; Bartoníčková, Eva (referee) ; Částková, Klára (advisor)
The thesis concerns the synthesis Ceric Oxide, Samarium Oxide and Samarium doped Cerium Oxide. The theoretical part is focused on the characteristics, applications and possibilities of the Cerium Oxide synthesis. The experimental part describes the precipitation of the Cerium Oxide powder. The synthesis of the powders were proceeded in the normal conditions or in the presence of ultrasonic field. For the purposes of description of the ready powders the x-ray diffraction (XRD) and the raster electron microscopy (SEM) were used. The ceramics were made of the selected powders where the structure was described by SEM, the density by Archimedes´Method and the grain size by grid-line intersect method. Using the precipitation synthesis, the pure powders of Ceric Oxide, Samarium Oxide and Samarium doped Cerium Oxide were prepared. The powder morphology was strongly involved by the pH level and by ageing time. The ultrasound was accelerating the ageing. At the values of pH > 11 the rodlike particles were created. The ageing time and the ultrasound supported the creation of the rodlike particles. The ceramics made of the powder with the presence of the rodlike morphology showed the density up to 97,14% of the theoretical density.
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Model study of biomolecules bonding to cerium oxide nanoparticles
Pittnerová, Daniela ; Matolínová, Iva (advisor) ; Vorokhta, Mykhailo (referee)
In the last few years cerium oxide due to its convenient properties for biomedical applications has been studied as a promising material for fabrication of third-generation of mediator-less enzymatic biosensors. The bonding of biomolecules with cerium oxide is a crucial parameter, which is difficult to study due to the complexity of the problem. Therefore the model studies on epitaxial and polycrystalline cerium oxide were carried out. In this thesis we continued in this line of the research with the complex study of bonding of amino acids histidine, glycine and sarcosine to cerium oxide nanoparticles. The nanoparticles' properties as the size and chemical composition were measured by electron microscopies and related techniques (TEM, SEM, EDX), and a series of photoemission spectroscopies (XPS, SRPES, RPES and NEXAFS). The dependence of zeta potential on the pH was measure by DLS technique.
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Model systems with the use of CeO2 for bioapplication
Bercha, Sofiia ; Tsud, Nataliya (advisor) ; Lykhach, Yaroslava (referee) ; Švec, Martin (referee)
Title: Model systems with the use of CeO2 for bioapplication Author: Sofiia Bercha Department: Department of Surface and Plasma Science Supervisor: Ing. Nataliya Tsud Ph.D., Department of Surface and Plasma Science Abstract: This thesis is focused on the investigation of model systems for bioapplications. Interfaces between biomolecules and inorganic materials were studied by means of advanced surface science techniques with emphasis on the molecular electronic structure and bonding geometry as a function of material morphology and/or molecular deposition method. For the histidine/cerium oxide system it is demonstrated that the morphology of the oxide determines the mechanism of the molecular adsorption. The presence of an aqueous medium does not alter the histidine interaction with the nanostructured cerium oxide. For the adenine/cerium oxide system we have shown that the adenine molecule chemisorbs on CeO2 intact via nitrogen atoms, independent of the oxide morphology and deposition technique. The adenine molecule was found to decompose on a reduced surface of the cerium oxide. Combining experimental and theoretical methods two distinct phases of adenine on CeO2 were found. For adenine/Cu(111) system it was shown that the strong interaction with the surface keeps the molecule intact on the surface till...
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Model study of biomolecules bonding to cerium oxide nanoparticles
Pittnerová, Daniela ; Matolínová, Iva (advisor) ; Vorokhta, Mykhailo (referee)
In the last few years cerium oxide due to its convenient properties for biomedical applications has been studied as a promising material for fabrication of third-generation of mediator-less enzymatic biosensors. The bonding of biomolecules with cerium oxide is a crucial parameter, which is difficult to study due to the complexity of the problem. Therefore the model studies on epitaxial and polycrystalline cerium oxide were carried out. In this thesis we continued in this line of the research with the complex study of bonding of amino acids histidine, glycine and sarcosine to cerium oxide nanoparticles. The nanoparticles' properties as the size and chemical composition were measured by electron microscopies and related techniques (TEM, SEM, EDX), and a series of photoemission spectroscopies (XPS, SRPES, RPES and NEXAFS). The dependence of zeta potential on the pH was measure by DLS technique.
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Synthesis of ceramic powder materials in the presence of the ultrasound field
Kočicová, Pavla ; Bartoníčková, Eva (referee) ; Částková, Klára (advisor)
The thesis concerns the synthesis Ceric Oxide, Samarium Oxide and Samarium doped Cerium Oxide. The theoretical part is focused on the characteristics, applications and possibilities of the Cerium Oxide synthesis. The experimental part describes the precipitation of the Cerium Oxide powder. The synthesis of the powders were proceeded in the normal conditions or in the presence of ultrasonic field. For the purposes of description of the ready powders the x-ray diffraction (XRD) and the raster electron microscopy (SEM) were used. The ceramics were made of the selected powders where the structure was described by SEM, the density by Archimedes´Method and the grain size by grid-line intersect method. Using the precipitation synthesis, the pure powders of Ceric Oxide, Samarium Oxide and Samarium doped Cerium Oxide were prepared. The powder morphology was strongly involved by the pH level and by ageing time. The ultrasound was accelerating the ageing. At the values of pH > 11 the rodlike particles were created. The ageing time and the ultrasound supported the creation of the rodlike particles. The ceramics made of the powder with the presence of the rodlike morphology showed the density up to 97,14% of the theoretical density.
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