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Thin-film systems
Kuchařík, Jan ; Máca, Josef (referee) ; Zatloukal, Miroslav (advisor)
This bachelor thesis concerns to create of thin films on various types of substrates. In the theoretical parts is an overview of the formation of thin films using several techniques. The thesis contains an overview of substrate cleaning processes before the deposition of layer plates and tools for evaluating their properties. Finally, the masking method is discussed. In the experimental part, the acquaintance with the NP - 12 sputtering device and the production of samples took place. The adhesion of the produced samples was evaluated. Electrolysis of samples with titanium coated followed. Finally, the silicon substrate was masked.
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A Study of Phenomena that Limit the Life-Span of Ni-Zn Secondary Cells
Chladil, Ladislav ; Oriňáková,, Renáta (referee) ; Vanýsek,, Petr (referee) ; Novák, Vítězslav (advisor)
This dissertation is focused on the study of selected additives and their effect on positive and negative electrodes of Ni-Zn secondary cells. The first group of additives consists of the inorganic compounds that reduce zinc oxide solubility and thus prevents shape changes of the zinc electrode. The second group contains organic additives that have the beneficial effect of dendrite growth prevention. All additives were examined in relationship to their compatibility with the positive electrode and to their effect on the zinc electrode dendrites inhibition, hydrogen evolution and corrosion inhibition. Moreover, the study of decomposition kinetics of supersaturated zincate solution with the first group of additives was performed. Finally, a short study of pulse regime charging mode with regard to dendrites inhibition was performed and evaluated.
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Thin layers TiO2 prepared by electrochemical way
Janov, Pavel ; Zatloukal, Miroslav (referee) ; Sedlaříková, Marie (advisor)
This work deals with issue of preparation active electrochromic film of titanium dioxide and intercalation properties. By electrodeposition was created active film on glass substrates covered with transparent conductive thin-film In2O3:Sn (ITO). The active films prepared by electrolytic way were compared with active films prepared by vacuum methods. Then has been studied theirs electrode properties in electrolytes containing lithium.
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Self-organized nanostructured oxide layers
Šťastná, Eva ; Pouchlý, Václav (referee) ; Jan, Vít (advisor)
Series of anodization experiments was conducted on pure aluminium (99,95 Goodfellow) substrates with the aim to map the possibilities and evaluate available techniques. Oxalic acid electrolyte was used for anodization at different voltage levels ranging from 20 to 60V, while current was always measured continuously during the experiment. The influence of substrate surface treatment, time and grain size of the substrate was documented for as anodized oxide structures using FEG-SEM. Well aligned and evenly distributed pores of the diameters ranging 20- 35 nm were achieved. Extremely fine pores down to 10 nm were achieved using the step-down technique governed by current limitation. Further post-anodizing treatment was evaluated – pore widening by chemical and electrochemical etching, which resulted in pores 80nm wide. The feasibility of electrodeposition of metallic wires directly into the AAO structure without substrate removal was evaluated. DC, AC symmetric and non-symmetric voltage setups were used. The deposition experiments results varied strongly depending on the post anodization treatment. For combination of pore-widening after anodizing with step-down stage, the deposition of copper nanowires was achieved. For simple step-down procedure, creation of very fine copper particles was realized using non-symmetric AC deposition. Further experiments and feasibility of metals electrodeposition in the AAO pores without substrate removal is discussed.
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Properties of electrode materials for alcaline accumulators
Fusek, Petr ; Vrbický, Jiří (referee) ; Sedlaříková, Marie (advisor)
The Bachelor´s Thesis is aimed at the problematic of the binders, that effects the features of the positive electrode of alcalic accumulators. The additive used on nickel´s electrode was cobalt. In the practical part of this thesis there is described a process for etching the nickel electrode and the following electrodepositions applied on these electrodes. Measurements of different concentrations of nickel and cobalt were examined and analysed in the graphs which are part of this thesis. There have been made comments of these graphs and the conclusions and observations as well.
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ELECTROCHEMICAL STUDY OF CuSCN INORGANIC HOLE-TRANSPORT MATERIAL FOR SOLAR CELLS PREPARED BY ELECTRODEPOSITION FROM AQUEOUS SOLUTION
Vlčková Živcová, Zuzana ; Mansfeldová, Věra ; Bouša, Milan ; Kavan, Ladislav
A comparative study is reported for electrodeposited copper(I) thiocyanate layers (ca. 500 nm) on two types of conductive/semiconductive substrates: i) carbon (boron-doped diamond_BDD, glass-like carbon_GC), and ii) carbon-free F-doped SnO2 conducting glass (FTO). SEM and Raman evidence that electrodeposition from aqueous solution results in homogenous CuSCN layers with dominant thiocyanate ion bounded to copper through its S-end (Cu−SCN bonding), as in spin-coated CuSCN layers. Electrochemical impedance spectroscopy (EIS) confirms the p-type semiconductivity of layers with a flatband potential from 0.1 to 0.18 V vs. Ag/AgCl depending on the substrate type, and the acceptor concentration (NA) of 5 x 1020cm-3 in all cases. The flatband potentials determined from Mott-Schottky plots (EIS) are in good agreement with the Kelvin probe measurements. The blocking quality of CuSCN layers was tested using Ru(NH3)63+/2+ redox probe. CuSCN deposited on BDD substrate exhibits better blocking properties compared to CuSCN deposited on FTO.
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Thin-film systems
Kuchařík, Jan ; Máca, Josef (referee) ; Zatloukal, Miroslav (advisor)
This bachelor thesis concerns to create of thin films on various types of substrates. In the theoretical parts is an overview of the formation of thin films using several techniques. The thesis contains an overview of substrate cleaning processes before the deposition of layer plates and tools for evaluating their properties. Finally, the masking method is discussed. In the experimental part, the acquaintance with the NP - 12 sputtering device and the production of samples took place. The adhesion of the produced samples was evaluated. Electrolysis of samples with titanium coated followed. Finally, the silicon substrate was masked.
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Electrochemical Deposition of Silver Amalgam Particles on Pyrolitic Graphite Electrode
Šebest, Peter ; Havranová-Vidláková, Pavlína ; Ligmajer, Filip ; Fojta, Miroslav ; Daňhel, Aleš
Silver solid amalgam represents suitable alternative electrode material to metallic mercury, Controlled electrodeposition of variable silver amalgam particles (AgAP) on the surface of pyrolitic graphite electrode from an electrolyte containing Agt It and Hg(II) ions is reported as a novel method suitable lot preparation of perspective supporting materials Scanning electron microscopy including energy-disperse X-ray spectrometer and image processing software were used for analysis of composition and morphology of AgAP on POE A model electrochemically reducible 4-niirophenol was used to test a potential applicability of AgAp-PGE in electroanalytical methods.
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Fabrication and characterisation of silver decorated TiO2 nanotubes for biomedical applications
Bílek, Ondřej ; Horynová, Miroslava (referee) ; Fohlerová, Zdenka (advisor)
This diploma thesis summarizes knowledge from the fields of synthesis, characterization and application of titanium dioxide nanotubes and its combination with silver nanoparticles for biomedical purposes. Basic protocols of working with cell cultures and bacteria are also included. Experimental part of this diploma thesis focuses mainly on the synthesis of tubular structures made of titanium dioxide via anodic oxidation of 500nm titanium layer and their subsequent decoration with silver by electrodeposition. Last section of the experimental part is devoted to testing of antibacterial properties of the new material and examining the effect of different silver concentrations on the adhesion of MG-63 cells. All results are compared to reference samples consisting of titanium dioxide nanotubes without silver.
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Oxidation barriers prepared by electrochemical procedures
Šťastná, Eva ; Pouchlý, Václav (referee) ; Jan, Vít (advisor)
A process with aim to prepare an oxidically and thermal resistant layer was performed on the samples from clear aluminium (99,99+ %, VÚK čisté kovy, s. r. o.) and on the samples from clear titanium (99,95 % Goodfellow) with a layer from sputtered aluminium (99,99 %, VÚK čisté kovy, s. r. o.), An oxidic layer was prepared on the samples by anodization in the oxalic acid. The layer had fine, hexagonally organized pores with the diameter of 30 nm. During the following processing was the structure prepared for the electrochemical deposition of copper to the pores. The aim of the electrodeposition was preparation of copper nanowires deposited into the pores of the oxidic layer. The process was performed in the solution of copper sulfate and sulfuric acid in water. The controlling parameter of the deposition was voltage which had a very asymmetric period. The period had to be optimized for a successful preparation of the wires. The result of the whole process was structure with oxidic matrix whose most of the pores were filled with copper.
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