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Progressive Amorphous Carbon Alloys Synthesized in Low-Temperature Plasma
Bránecký, Martin ; Trunec, David (referee) ; Kylián,, Ondřej (referee) ; Čech, Vladimír (advisor)
Atomic/plasma polymerization technology is widely used in various technical fields. This work is focused to use the PE-CVD technology in the field of formation of interphase and adhesive layers, which are developed into layered nanostructures. To ensure reproducible chemical and physical properties of the materials, the deposition process was monitored by mass spectrometry. Vapours of the pure tetravinylsilane, or a mixture of these vapours with oxygen, was used as a precursor for atomic polymerization, which results in the thin films with a large variability of properties. Physical and chemical properties were varied by the effective power delivered to the plasma discharge. The deposited films were analyzed from different perspectives using several methods (in situ spectroscopic ellipsometry, FTIR, nanoindentation, AFM). The removal of hydrogen atoms from the carbon-silicon network results in increased crosslinking of the material, which controls the mechanical and optical properties of the deposited layers. From the precisely defined a-CSi:H and a-CSiO:H materials, layered nanostructures composed of 3 and 7 individual layers was subsequently constructed. These nanostructures were analyzed by XPS and RBS to determine the atomic concentrations of carbon, silicon, oxygen and their binding states.
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Preparation of layers by plasma polymerization and their characterization
Kostyleva, Kseniia ; Trunec, David (referee) ; Mazánková, Věra (advisor)
The diploma work deals with the preparation of biocompatible hydrophilic layers from a propane-butane mixture by plasma polymerization. Subsequent characterization of the layers was performed using both biological (antibacterial tests and biocompatibility test) and physico-chemical diagnostics (SEM, OES and surface energy determination). The theoretical part presents the basic principle of dielectric barrier discharge, its use and various types, including surface dielectric barrier discharge (SDBD), which was used during deposition. Next, cell cultures, cell morphology and clarification of the term biocompatibility were described. At the end of the theoretical part, all used during the experimental part of the diagnostics were also described. In the experimental part, the procedure of deposition of hydrophilic layers and the overall apparatus, which was used during deposition, were presented. Prior to the characterization of the samples, the discharge was diagnosed using optical emission spectroscopy. Furthermore, the level of hydrophilicity of the layers and their elemental composition on the surface was determined. Biological tests for biocompatibility and antibacterial properties provided information on the viability of the cells on the layers and their antibacterial effects.
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Study of plasma activated water properties
Maďarová, Štefánia ; Trunec, David (referee) ; Mazánková, Věra (advisor)
ABSTRAKT The goal of the diploma thesis was to carry out professional research focused on the formation of chemically active particles in plasma and their identification. The experiment was performed for the preparation of plasma activated water (PAW), using a hydrodynamic cavitation plasma jet device (HCPJ). The main goal of the experimental part of the thesis was the analysis and determination of the concentration of active particles generated during the experiment. The active particles I dealt with in my work were nitrates, nitrites and hydrogen peroxide. Samples of commercial (Danube) water, treated distilled water, treated tap water and treated Mixbed water were analysed. In addition to the production of reactive particles, their temporal stability was also studied. The samples were stored at room temperature. As the samples aged, the concentration values of the active particles changed due to mutual interactions between the particles, when nitrites were oxidized to nitrates. Physical properties of PAW, pH value and conductivity were monitored in the work. After PAW preparation, the conductivity increases due to the increase in the concentration of active particles created during the dissociation and ionization of water molecules by plasma treatment. The particles present in the air contribute to the increase in conductivity, they dissociate and ionize the plasma, which diffuse into the liquid. A drop in pH is the cause of an increase in the concentration of hydrogen ions and the formation of nitric acids. It was found that PAW does not retain its activated effects for too long, with aging the concentration of active particles decreased. The theoretical part is focused on plasma-activated water, its preparation, produced particles and their stability. The work also describes the use and application of PAW in agriculture, biomedicine and other industries. Various types of plasma discharge preparation are described. I also deal with the preparation of Mixbed water from Danube water. In the diploma thesis, we analyzed the plasma discharge using optical emission spectroscopy (OES). The measurement by OES was in the range of wavelengths from 200 to 1100 nm. The measurement by OES was in the range of wavelengths from 200 to 1100 nm. In the overview spectrum using tap water measured in the visible region, H-alpha, H-beta, H-gamma can be seen.
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Electron-Ion Recombination at Temperatures below 300K
Kotrík, Tomáš ; Glosík, Juraj (advisor) ; Pysanenko, Andriy (referee) ; Trunec, David (referee)
Title: Recombination study of ions with electrons at temperatures below 300 K Author: Tomáš Kotrík Department: Department of Surface and Plasma Science Supervisor of the doctoral thesis: Prof. RNDr. Juraj Glosík, DrSc. Department of Surface and Plasma Science Abstract: Presented is the study of recombination of ions with electrons performed at low temperatures using the Flowing afterglow with Langmuir probe experimental technique. Studied was the dissociative recombination of H and D ions at temperatures 77 - 300 K. Apart from a two-body also a three-body recombination channel assisted by neutral He atoms was identified and studied. The obtained temperature dependence of the two-body recombination rate coefficient is in a good agreement with findings of other experimental and theoretical works. The dissociative recombination of HCO and DCO ions with electrons was studied in the temperature range 150 - 300 K. The observed temperature dependence of measured recombination rate coefficient for HCO and DCO ions (~T -1.3 and ~T -1.1 , respectively) is in agreement with the majority of previous experimental works and evokes that indirect mechanism governs the recombination process. The electron- assisted collisional-radiative recombination of Ar ions was for the first time studied at temperatures 50 - 300 K. The...
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Preparation of layers by plasma polymerization and their characterization
Kostyleva, Kseniia ; Trunec, David (referee) ; Mazánková, Věra (advisor)
The diploma work deals with the preparation of biocompatible hydrophilic layers from a propane-butane mixture by plasma polymerization. Subsequent characterization of the layers was performed using both biological (antibacterial tests and biocompatibility test) and physico-chemical diagnostics (SEM, OES and surface energy determination). The theoretical part presents the basic principle of dielectric barrier discharge, its use and various types, including surface dielectric barrier discharge (SDBD), which was used during deposition. Next, cell cultures, cell morphology and clarification of the term biocompatibility were described. At the end of the theoretical part, all used during the experimental part of the diagnostics were also described. In the experimental part, the procedure of deposition of hydrophilic layers and the overall apparatus, which was used during deposition, were presented. Prior to the characterization of the samples, the discharge was diagnosed using optical emission spectroscopy. Furthermore, the level of hydrophilicity of the layers and their elemental composition on the surface was determined. Biological tests for biocompatibility and antibacterial properties provided information on the viability of the cells on the layers and their antibacterial effects.
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Progressive Amorphous Carbon Alloys Synthesized in Low-Temperature Plasma
Bránecký, Martin ; Trunec, David (referee) ; Kylián,, Ondřej (referee) ; Čech, Vladimír (advisor)
Atomic/plasma polymerization technology is widely used in various technical fields. This work is focused to use the PE-CVD technology in the field of formation of interphase and adhesive layers, which are developed into layered nanostructures. To ensure reproducible chemical and physical properties of the materials, the deposition process was monitored by mass spectrometry. Vapours of the pure tetravinylsilane, or a mixture of these vapours with oxygen, was used as a precursor for atomic polymerization, which results in the thin films with a large variability of properties. Physical and chemical properties were varied by the effective power delivered to the plasma discharge. The deposited films were analyzed from different perspectives using several methods (in situ spectroscopic ellipsometry, FTIR, nanoindentation, AFM). The removal of hydrogen atoms from the carbon-silicon network results in increased crosslinking of the material, which controls the mechanical and optical properties of the deposited layers. From the precisely defined a-CSi:H and a-CSiO:H materials, layered nanostructures composed of 3 and 7 individual layers was subsequently constructed. These nanostructures were analyzed by XPS and RBS to determine the atomic concentrations of carbon, silicon, oxygen and their binding states.
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Electron-Ion Recombination at Temperatures below 300K
Kotrík, Tomáš ; Glosík, Juraj (advisor) ; Pysanenko, Andriy (referee) ; Trunec, David (referee)
Title: Recombination study of ions with electrons at temperatures below 300 K Author: Tomáš Kotrík Department: Department of Surface and Plasma Science Supervisor of the doctoral thesis: Prof. RNDr. Juraj Glosík, DrSc. Department of Surface and Plasma Science Abstract: Presented is the study of recombination of ions with electrons performed at low temperatures using the Flowing afterglow with Langmuir probe experimental technique. Studied was the dissociative recombination of H and D ions at temperatures 77 - 300 K. Apart from a two-body also a three-body recombination channel assisted by neutral He atoms was identified and studied. The obtained temperature dependence of the two-body recombination rate coefficient is in a good agreement with findings of other experimental and theoretical works. The dissociative recombination of HCO and DCO ions with electrons was studied in the temperature range 150 - 300 K. The observed temperature dependence of measured recombination rate coefficient for HCO and DCO ions (~T -1.3 and ~T -1.1 , respectively) is in agreement with the majority of previous experimental works and evokes that indirect mechanism governs the recombination process. The electron- assisted collisional-radiative recombination of Ar ions was for the first time studied at temperatures 50 - 300 K. The...
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