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Synthesis of core/shell quantum dots for diagnostics
Mihajlović, Ana ; Vaculovičová, Markéta (referee) ; Pekárková, Jana (advisor)
This thesis deals with biosensors based on modified semiconductor core/shell quantum dots (QDs) for diagnosis. The work is divided into four main parts. The first one discusses the theory required for the use of QDs in bioaplications, there are described methods of synthesis, modification, application and bioconjugation of QDs. In the experimental part, CdTe/ZnS QDs with core/shell structure were prepared, in which the core was modified by MPA, GSH and TGA. In the next step, these QDs were further modified using CDI, EDC and NHS as mediators in order to increase affinity to BSA (bovine serum albumine) and IgG (imunoglobuline G). Prepared conjugates were characterized by fluorescence spectroscopy (Infinite M200Pro, Tecan) and capillary electrophoresis (Agilent 7100).
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Printed transparent oxide conductors
Bartoš, Radim ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
Thin films of tin oxide doped by fluorine or antimony were prepared by spincoating technique and material printing technique. Plenty of inorganic and organic coumpouds were used as precursors of fluorine and antimony. Sheet resistence of films were measured by 4-probe method and film thickness were determined by contact profilometer. Films were analyzed by Xray diffraction (XRD) and scan electron microscopy (SEM).
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Electroassisted photocatalysis
Filipská, Markéta ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This thesis is focused on fotoelectrochemical cells, where as photocathode is used titanium dioxide coated on conductive FTO glass and as counter electrode is used gold electrode. Thesis is also focused on relationship between intensity of irradiation and Faradaic efficiency and also influence of the overvoltage to the rate of degradation od the model pollutant, in this case Acid Orange 7. Electrical properties were measured by recording values of photocurrent. The aim of this thesis was to study influence material composition of photoanode and connection with intensity of irradiation, rate of degradation proces of model pollutant and current.
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Synthesis and properties of tungsten tioxide layers fabricated by the sol-gel process
Hesková, Helena ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This work deals with the optimization of the preparation process of WO3 layers by the sol-gel method and their properties. Several precursor solutions were prepared which were applied to the substrate by spin-coating and drop-casting. The deposited layers were annealed at 450°C until complete degradation of the polymer matrix contained in the precursor. The structure of the layers was observed by scanning electron microscopy, their composition by the X-ray diffraction and their thickness was determined by profilometry. The properties of the prepared layers were also investigated by photoelectrochemical measurements.
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Investigation of titania dispergation by ball milling
Gregůrek, Martin ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This bachelor’s thesis deals with preparation of dispersed suspensions of titania suitable for material printing. The theoretical part deals with the properties of dispersions, methods of their preparation and capabilities analysis particle size of the dispersions. Experimental work has been focused on the study of the efficiency of milling depending on time. The particles were prepared by ball milling with glass balls in n-butanol of oscilating shaker LT2. Characteristics of the dispersions was evaluated on the device for measuring particle distribution Lasentec D600L by laser diffraction. The results were verified on the devices Zetasizer Nano ZS using dynamic light scattering and scanning electron microscope Carl Zeiss Ultra Plus.
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Magnetic particles as analytical tool in medicine
Gablech, Evelína ; Pekárková, Jana (referee) ; Hubálek, Jaromír (advisor)
This work reports on knowledge of magnetic nanoparticles, modification of their surface and their using in different areas. Literature review describes using MNPs in separation techniques of analytic biochemistry to imobilizate nucleic acids and proteins. The matter of experimental part is synthesis of MNPs using coprecipitation of iron salts and next modification of their surface. In MNPs preparation the effect of the presence of PEG in the reaction mixture and the temperature effect on the resulting properties of MNPs was examined. MNPs surface was modified by two different methods, emulsion polymerization method with precursors MMA and AAc, and carboxylation method using 11 -mercaptoundecanoic acid. PEG or temperature had little effect on the properties of the prepared MNPs. Establishing carboxyl groups succeeded only when the method of emulsion polymerization was used.
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Switching of spin vortices in magnetic nanodiscs
Hladík, Lukáš ; Pekárková, Jana (referee) ; Urbánek, Michal (advisor)
The diploma thesis deals with the switching of spin vortices in magnetic nanodisks. First, the basic concepts of (micro)magnetism are defined and existing theoretical and experimental achievements in the field of switching of the two basic characteristics (chirality and polarity) of magnetic vortex are summarized. Then the principle of dynamic switching of magnetic vortex chirality using in-plane magnetic field pulse with a well defined amplitude and duration is presented. There is no need to use a certain shape of nanodisks or asymmetry in magnetic field distribution. Nanostructures were prepared by the multi-step electron beam lithography and ion beam sputtering. Individual steps of sample preparation and optimization for the magnetization dynamics measurements are described. Finally, the experimental measurements of the dynamic switching of chirality on prepared samples obtained by transmission x-ray microscopy at the synchrotron Advanced Light Source at Berkeley, USA are presented and discussed.
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Increase of Belite Clinker Reactivity
Pekárková, Jana ; Fridrichová, Marcela (referee) ; Gazdič, Dominik (advisor)
Bachelor's thesis is focused on possible increase of belite clinker reactivity. Specfically a method of chemical activation was examinated. This method consists in disruption of belite structure due to substitution silicon ions with other ion. It also deals with effect of potassium ions from potassium sulfur and carbon on longterm hydration process of belite clinker, which was burnt in laboratory.
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Peroxotitanate gels suitable for piezoelectric print
Fuksa, Andrej ; Pekárková, Jana (referee) ; Veselý, Michal (advisor)
This thesis provide information about deposition of thin layers from peroxotitanate precursor. Precursor containing peroxotitanic acid and mixture of solvents (isopropanol and ethyleneglykol), was printed with the ink-jet material printer. Glass slides were used as a substrate. Prepared layers of gel did not show photocatalytic activity, therefore calcination at 450 °C, was used to a gel conversion. Structure of the layers was characterized using optical and SEM microscopy. Photoactivity of the layers was studied by a hydroxy-lation of cumarine.
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