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Light induced catalytic degradation of a series of common antibiotics and the corresponding HPLC analysis
Smítková, Karolína ; Klusoň, Petr (advisor) ; Krystyník, Pavel (referee)
1 Abstract The continuous advance in industry, general intensification of processes and urbanisation inevitably leads to production of new substances each year, collectively referred to as emerging pollutants (EPs). As the mass production of EPs increases, the demand for wastewater treatment plants also dramatically increases. The inadequacy of conventional tretament plants in removing EPs, such as pharmaceuticals, pesticides, personal care products, and others, results in the presence of these substances in surface and groundwater at significant concentrations. The often negative or unclear impact of EPs to the environment furhter emphasizes the urgency of this issue and requires a corresponding response. Photocatalysis belongs to the co-called advanced oxidation processes, key techniques for ensuring effective wastewater treatment. This thesis is focused on the photocatalytic degradation of tetracycline, trimethoprim and sulfamethoxazole, three common antibiotics frequently found in wastewater. Graphitic carbon nitride, a promising material in research of fotocatalytic degradation, was used as a photocatalyst and was activated by visible light emitted from a mercury xenon lamp. Experiments were conducted in batch setup and in microphotoreactor to compare the efficiency of both systems. Rhodamine B was...
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Material printing of UVB disposable dosimeter
Fryčová, Gabriela ; Ettler,, Karel (referee) ; Veselý, Michal (advisor)
The aim of the bachelor's thesis was the preparation of photosensitive layers responding by colour change to the exposure dose and their subsequent calibration to UVB irradiation doses of 500 and 1 000 mJcm2 using calibration agents and layer thickness change. The experimental part focuses on the preparation and application of the layers and the study of their colour response to the exposure dose. The validity of the reciprocity law was verified. The simplicity of preparation and use of the resulting disposable UVB dosimeters was emphasized.
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Photopolymerization
Kučera, Vladimír ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The bachelor thesis deals with the photochemistry of macromolecular substances, especially with photopolymerization and photocrosslinking reactions. In the theoretical section there is at first a summary of the current knowledge from the area of the general photochemistry and principles of photochemical reactions which are also applied in photopolymerization. There are also both types of photopolymerization analysed – cationic and free-radical, photocrosslinking reactions and photopolymerization applications. In the experimental part, the testing of two fotopolymerization systems was performed. In both of them, styrene was used as a monomer. In one case benzoin was used as a photoinitiator, in the second one there was benzoin ethyl ether used. Furthermore, the photoinitiation ability of these two photoinitiators was compared at the base of conversion and molecular weight of products that were synthetized at different concentrations of photoinitiators and different time periods of irradiation of the mercury lamp.
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Printed chemical sensors of UV light
Fanglová, Michaela ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
The main task of the bacherol´s thesis was to prepare a photosensitive layer reacting to the radiation dose with a color change. And to calibrate the prepared dosimeters to the required values of the radiation doses of the UVB radiation. This bacherol´s thesis is about light dosimeters, which are based on photochemical reactions. These reactions take place in a thin polymer layer. The experimental study focoused on the preparation and application of photosensitive compositions. These prepared dosimeter compositions were exposed to different doses of UVB radiation, where the color response to the exposure was monitored.
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Kinetic study of photochemical reactions in thin printed layer
Rudická, Andrea ; Čeppan,, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with a study of kinetics of photochemical reactions in a thin printed polymer layer. The experimental part deals with the composition preparation and layers coating. The prepared layers were exposed and subsequently studied for their colour response to the light. The aim of this work was to prepare a photosensitive layer with a significant colour change between individual doses of radiation, to improve the mechanical resistance of the layers, to adjust the sensitivity of the compositions to UVB radiation and to study the kinetics of the photochemical reaction used.
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Photosensitive thin polymeric layers
Rudická, Andrea ; Klusoň, Petr (referee) ; Veselý, Michal (advisor)
This bachelor thesis deals with photosensitive thin polymeric layers. The experimental part deals with the composition preparation and layers coating. The prepared layers were exposed and studied in detail for their color response to the light. The aim was to prepare a dosimeter, to achieve significant color change between individual doses, to improve the mechanical resistence of the layers and to adjust the sensitivity of the compositions to UVB radiation.
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The Study of Polyolefins Photochloration
Kučera, Vladimír ; Tocháček, Jiří (referee) ; Petrůj, Jaroslav (advisor)
This Master´s thesis deals with heterogeneous photochlorination of polyolefins and especially with the photochlorination of polypropylene itself. In the theoretical part the available information about properties, manufactory and application of chlorinated polyolefins, specifically polyethylene and polypropylene, is provided. The basic principles of the photochemistry are described, which are further applied to the issue of photochemistry chain reactions and photochemical halogenations, mainly photochlorinations. The practical part includes design and realization of few types of equipment for the heterogeneous photochlorination of polypropylene done at low temperatures (to 50° C) by gaseous chlorine in bulk or chlorine suspended in suspension of PP in CCl4. Series of chlorination was accomplished, which was varied in the type of PP, in the way of dosage Cl2 and in the period of high pressure mercury lamp irradiation (1–90 minutes). The chlorine content in prepared samples was determined by the gravimetry with ATR-FTIR spectroscopy, as well as by the Shöniger combustion method. Their accuracies were than compared. The chlorine content dependence on the period of chlorination and on the porosity of initial PP was established.
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Advanced plasmonic materials for metasurfaces and photochemistry
Ligmajer, Filip ; Vala,, Milan (referee) ; Bauch, Martin (referee) ; Šikola, Tomáš (advisor)
Plazmonika, tedy vědní obor zabývající se interakcí světla s kovovými materiály, nabízí ve spojení s nanotechnologiemi nezvyklé možnosti, jak světlo ovládat a využívat. Výsledkem tohoto spojení může být například zaostřování světla pod difrakční limit, zesilování emise nebo absorbce kvantových zářičů, či extrémně citlivá detekce molekul. Tato práce se zabývá zejména možnostmi využití plazmoniky pro vývoj plošných optických prvků, tzv. metapovrchů, a pro fotokatalytické aplikace založené na plazmonicky generovaných elektronech s vysokou energií, tzv. horkých elektronech. Nejprve jsou vysvětleny teoretické základy plazmoniky a je poskytnut přehled jejích nejvýznamnějších aplikací. Poté jsou představeny tři studie zabývající se využitím plazmonických nanostruktur pro ovládání fáze a polarizace světla, pro vytváření dynamicky laditelných metapovrchů, a pro foto-elektrochemii s horkými elektrony. Společným prvkem těchto studií je pak používání pokročilých, resp. v rámci těchto oblastí netradičních, materiálů, jako např. oxidu vanadičitého nebo dichalkogenidů přechodných kovů.
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Catalytic and photochemical cycloadditions of alkynes
Fadeev, Aleksandr ; Kotora, Martin (advisor) ; Pour, Milan (referee) ; Parkan, Kamil (referee)
Novel approaches to utilizing alkynes in transition metal-catalyzed [2+2+2] cycloadditions and photochemical [2+2] cycloadditions were investigated with respect to the potential applications of these transformations. First, a chemo- and regioselective fully intermolecular cocyclotrimerization of internal alkynes with a commercially available ethynyl boronate was developed using Ru-catalysis and its mechanism was examined using DFT calculations. The established method allows for a straightforward preparation of various 1,4-diborylated benzenes, which can serve as multifunctional building blocks in organic synthesis. In particular, the products can be used in cross-coupling, carbonylation and oxidation reactions to access a broad variety of contiguously substituted arenes, such as natural products mirandamycin and violaceoid C. Second, a comparative study of catalytic and uncatalyzed photocycloadditions between alkynes and quinones was undertaken. Contrary to the recent reports, irradiation with visible light alone is sufficient to obtain not only the [2+2] cycloaddition products, but also several products of cascade transformations. Thus, depending on the structure of the quinone used, either carbo- or heterocycloaddition pathway is mainly realized, giving rise either to annulated cyclobutenes or...
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Exploration of extraterrestrial body impact and UV-driven transformation of atmospheres of terrestrial planets
Knížek, Antonín ; Ferus, Martin (advisor) ; Kabáth, Petr (referee) ; Kopecký, Vladimír (referee)
Keywords: Exoplanets, Earth, Impact, Photochemistry, Infrared Spectroscopy, Atmospheric chemistry Impacts and photochemistry are two very important driving forces for chemical transformation of planetary atmospheres. While strong UV radiation produced by young stars continuously provides a significant amount of energy, impacts are one-time events with far-reaching consequences. Especially important are then impacts on young rocky planets, including the early Earth, because these planets are likely exposed to much higher impact fluxes, commonly called 'heavy bombardment'. This bombardment is the final echo of the turbulent planetary accretion and has prominent significance for planetary environments, e.g., the chemical composition and shape of the planetary surface, the chemistry of atmospheres, aerosol production, and likely the origin of life. Future observations of exoplanets by space telescopes, such as the James Webb Space Telescope or Ariel, as well as ground-based telescopes, such as the Extremely Large Telescope currently under construction in Chile, could determine whether this heavy bombardment represents a common scenario for the evolution of terrestrial planets. Both impacts and photochemistry can be efficiently simulated and studied in laboratory conditions by state-of-the-art methods....
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