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Antibacterial activity of photoactive surfaces
Rabenseifnerová, Barbora ; Králová, Marcela (referee) ; Veselá, Mária (advisor)
This master's thesis deals with the antibacterial activity of photoactive surfaces in flia with a known content of zinc pyrithione in combination with the photoactive part. Individual flia were exposed to illumination for a given period of time to confirm photoactive ability and stored for comparison in the dark for the same time. The imprinting method was used and supplemented by a method based on ISO standard 27447:2019.
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Antimicrobial Activity Evaluation of Biocidal Surfaces with Resazurin Assay
Patakyová, Sylvia ; Viktorová,, Jitka (referee) ; Králová, Marcela (advisor)
This diploma thesis deals with the determination of antimicrobial activity of surfaces with biocidal effect using the resazurin test. The resazurin method of determination is a non-invasive colorimetric method with great potential for widespread use. However, its use so far has been limited as it is not included among standardized methods. The colorimetric method was used as a way to evaluate the effectiveness of immersion experiments using antimicrobial films and the bacterial strain Escherichia coli. The fluorescence intensity of the dye in the suspensions, which were affected by the individual foils, was captured by photographic recording and subsequently evaluated using image analysis. The measured and calculated values of the antimicrobial effect of three samples of active foils with different concentrations of the biocidal substance were compared with the results obtained in conditions with a smaller error rate (using plate-reader) and with the results obtained through a standardized method to demonstrate the relevance of the resazurin method and to assess the antimicrobial activity of studied surfaces.
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Hydrogel carriers of microbial cultures for contact sampling of biocidic surfaces
Antálek, Adam ; Králová, Marcela (referee) ; Dzik, Petr (advisor)
This bachelor thesis is focused on the development and optimization of material for biological sampling of active surfaces with biocidal properties. The aim was to modify polyvinyl alcohol with methacrylic groups, to determine the degree of conversion of the prepared polymer, to optimize the preparation of hydrogels. Furthermore, the aim was to investigate the effect of copolymerization aditives of sodium methacrylate and polyethylene glycol dimethacrylate on the swelling and mechanical properties of hydrogels. It was found that 20% vol. the content of polyethylene glycol dimethacrylate most significantly increases the swelling rate in the initial phase of water absorption. The hydrogels of this composition and the hydrogels consisting only of pure methacrylated polyvinyl alcohol, despite the assumption, increase the mechanical resistance after swelling to equilibrium. The hydrogels of the composition containing both copolymer aditives absorb water at equilibrium to the highest extent of the investigated compositions.
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Outdoor applications of photocatalytic materials
Šimončičová, Monika ; Králová, Marcela (referee) ; Veselý, Michal (advisor)
This bachelor thesis deals with the evaluation and optimization of the method for the determination of photocatalytic activity of facade coating layers with and without photocatalyst admixture titanium dioxide. The layers are tested by the photooxidation of the organic dyes Acid orange 7 and methylene blue, which are model compounds of pollution. Degradation of organic dyes is monitored by UV-VIS spectrophotometry and evaluated by determination of rate constants and specific photoactivity. The aim is to find out which of the facade coating has the highest photoactivity.
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Photocatalytic activity of hybrid titanium dioxide layers treated by plasma
Koukolová, Anna ; Králová, Marcela (referee) ; Veselý, Michal (advisor)
The bachelor thesis deals with photocatalytic activity of thin layer of titanium dioxide deposited onto PET flexible foil treated by plasma. Photocatalytic activity is measured by two different methods, degradation of dye Acid Orange 7 and benzoic acid. Possible model compounds for evaluation of photocatalytic activity as well as deposition techniques for preparing thin layers of photocatalyst were discuss in the theoretical part. Changes of photocatalytic activity were found insignificant with plasma treatment. Evaluation used Acid Orange 7 is suitable. Unlike method with benzoic acid was discovered inappropriate for measuring of photocatalytic activity for photocatalyst deposited onto PET foil.
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UV dosimeter for safer sunbath
Hinca, Sven Barbara ; Králová, Marcela (referee) ; Veselý, Michal (advisor)
V dnešní době je veřejnost konstantně vystavená slunečímu světlu a tím také UV záření. Protože UV radiace je prokázaným karcinogenem a kvůli rapidnímu zmenšování ozonové vrstvy v nedávné minulosti, monitorování osobního vystavení UV záření, a povědomí o riskantnosti ozáření vyššího než je bezpečná dávka, je důležitější než kdykoliv předtím. Tato práce je zaměřená na vývoj a zjednodušení osobní UV dozimetrie pro použití veřejností tak, aby každý uměl vyhodnotit riskantnost delšího vystavení UV radiaci.
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Photoelectrochemical oxidation of aqueous polutants
Pachovská, Martina ; Králová, Marcela (referee) ; Dzik, Petr (advisor)
The thesis is focused on the use of photochemical reactions and their applications for removal of aqueous pollutants such as organic acids. For evaluation of photochemical oxidation was used benzoic acid as model pollutant. Decreasing of concentration and oxidation products were monitored by UV-VIS spectrometry. The formation of oxidation products was observed by fluorescence measurement. Subsequently the stability and properties of model aqueous pollutant and electrochemical properties of used photoelectric cells were studied. The aim was to determine the appropriate reaction conditions and limits of degradation reaction.
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Self-cleaning Properties of Thin Printed Layers of Titanium Dioxide
Králová, Marcela ; Brezová, Vlasta (referee) ; Krýsa, Josef (referee) ; Veselý, Michal (advisor)
Tenké vrstvy oxidu titaničitého byly imobilizovány na sodnovápenatá skla a skelný uhlík použitím jak techniky materiálového tisku tak metodou chemického napařování. Pro přípravu titaničitých solů byly použity metody sol-gelu a nebo hydrotermální syntézy. Struktura připravených vrstev byla zkoumána rastrovací elektronovou mikroskopií a mikroskopií atomárních sil. Krystalická struktura připravených TiO2 byla analyzovány pomocí XRD metody. Fotoindukováná superhidrofility pripravených vzorků byla charakterizována měřením kontaktních úhlů. Fotokatalytická aktivity připravených vzorků byla testována na fotokatalytické oxidaci 2,6-dichlorindofenolu a kyseliny mravenčí. V případě sol-gel vrstev byl zkoumán vliv množství naneseného TiO2 a množství PEG, který byl do solu přidán jako praskliny potlačující činidlo. V případě hydrotermálních vrstev byl zkoumán vliv času a teploty syntézy a množství vrstev na výslednou účinnost vzorku. U chemicky napařených vzorků byl zjišťován vliv intenzity záření. Byla porovnána fotokatalitická aktivita vrstev připravených materiálovým tiskem a chemickým napařováním a byl vyhodnocen nejaktivnější vzorek.
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Synthesis of bioceramic materials based on hydroxyapatite
Kočicová, Pavla ; Králová, Marcela (referee) ; Částková, Klára (advisor)
The thesis deals with the precipitation synthesis of nanoparticle hydroxyapatite with goal to study the influence of reaction conditions on the morphology of the particles. The theoretical part is focused on biomaterials, bioceramics and phosphates characterization. Further the work is focused on hydroxyapatite, its characteristics and possible synthesis in particular. The synthesis of hydroxyapatite precipitation is described in the experimental part. Syntheses were performed at a reaction temperature of 0-80 °C at pH = 8-11, at the aging time of 0-24 h, in the presence of surfactant and the chelating agent and with the post-precipitation hydrothermal or ultrasonic treatment. For characterization of the prepared powders, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), laser diffraction (LD) and the analysis of the specific surface area (BET) were used. Pure hydroxyapatite powders or a mixture of hydroxyapatite and tricalcium phosphate were prepared by precipitation syntheses. HA particle morphology was strongly affected by the reaction temperature – with increasing temperature the larger particles with a clearer morphology were formed, mostly in the rod shape. Postprecipitation hydrothermal treatment had a significant influence on the morphology of HA particles – it caused the formation of spherical or slightly elongated particles. The reaction medium of water/ethanol significantly affected the particle morphology – it inhibited the particle growth.
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Investigation of Methacrylated PVAl Photochemical Crosslinking
Králová, Marcela ; Čeppan, Michal (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with a detailed study of photoinitiated radical polymerization of macromers base on PVAl containing lateral GMA moieties. The main goal is the evaluation of the influence of photoinitiator concentration, polymerisable group content and/or other aditives on the polymerisation rate. Other goals include the study of possible influencing the photochemical speed by lowering the glass transition temperature, compatibility with various photoinitiators etc. Attention is also paid to the study of prepared 3D polymeric networks properties
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