|
|
Microbial contamination of photographic materials
Ouředníčková, Veronika ; Dzik, Petr (referee) ; Veselá, Mária (advisor)
This diploma work is focused on a study of microbial contamination of photographic materials. In the first part of this work the information about the archive and museum microbial contaminations were collected. The most frequent contaminants of photographic collections – Penicillium chrysogenum and Aspergillus niger were studied. Their activity on photographic papers Fomaspeed and Fomabrom was evaluated. It was found that at the given experimental conditions the image layers of Fomaspeed paper are resistant to fungi mycelium growth. On the other hand, the Fomabrom paper image layer was irrecoverably damaged by action of fungi mentioned above. The degree image layer deterioration was evaluated with the aid of sensitometric curves.
|
|
|
Synthesis and Characterization of PVAl Acrylic Esters
Hynštová, Karolína ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
The diploma thesis deals with a detailed study of he esterification reaction between PVAl and acrylic and methacrylic acids. Tha goal is to prepared PVAl-based macromers bearing (meth)acrylic moieties bound to PVAl macromolecular backbone. Attention will be paid especially to equlibrium establishing times and to the influence of reaction mixture composition on the properties of resulting products.
|
|
|
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
|
|
|
Solid Foams Based on Acetalized PVAl
Mach, Václav ; Klučáková, Martina (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with the preparation of solid hydrophilic sponges made of acetalized PVAl. The sponges were produced by foaming by gaseous reaction by-product. The experimental work also includes the study of active compound immobilization into the sponge (finely ground lignite as a heavy metal sorbent).
|
|
|
Physical-chemical property characterisation of thin reflective layers on polymer substrates
Stružínský, Ondřej ; Dzik, Petr (referee) ; Krčma, František (advisor)
This work deals generally with surface diagnostic and optical properties of thin layers which are created by plasma polymerization of hexamethyldisiloxane monomer. The influence of oxygen adittion on thin layers properties was studied, too. This polymer layers are commercially made to protect reflective layers in the headlights. Thin layers were made in deposition chamber AluMet 1800V at Zlin Precision Company. Teoretical part of this work deals with methods which are used for deposition of thin layers, mainly physical (PVD) and chemical (PECVD, CVD) depositions. The conditions which influenced plasma polymerization itself are discussed as well as, monomers which are used for plasma polymerization and stability of thin polymer layers. Also there are mentioned the most frequent plasma processes diagnostic methods applicable during the deposition (optical emission spectroscopy) and methods for thin layers diagnostic (wettability, UV-VIS and infrared spectroscopy). Spectrometer Jobin Yvon Triax 320 was used for emission spectra acquisition during the plasma deposition. There were analyzed only two spectra created at same conditions as power at 3 kW and monomer flow rate at 100 sccm; the first one was in pure monomer, the second was obtained with oxygen addition of 150 sccm into the monomer flow. There was not found any essential differences between these spectra in the range 300 nm to 800 nm. Besides the thin layers analyzes after their formation, the samples were exposed to common aging conditions with respect to their use. One third of the prepared samples was exposed by ultraviolet radiation for 48 hours (exposure power of 0.68 W.m-2 at 340 nm) and the other part of samples was inserted for four days into NaCl solution of 50 g.l-1. The surface properties of layers were studied by their contact angle with three liquids (water, diiodmethane, and glycerol) that allowed their surface energy calculation. Results of this measuring are as following: Oxygen addition decreased contact angle of water after exposure of UV radiation. If the highest flow rate of monomer was used and oxygen was added, NaCl degradation did not have any significant influence on contact angle to water. Optical properties of prepared thin films were characterized by UV-VIS spectroscopy. Optical properties were measured only for samples after deposition and samples that were exposed by ultraviolet radiation. Results showed that oxygen addition into the reacting mixture increased the light absorption in UV-VIS (300-800 nm). The absorption was significantly increased after exposure of ultraviolet radiation. With respect to the application of these thin layers is necessary to say that this influence is undesirable. On the other hand, absorption of thin layers deposited at 2 kW, without oxygen addition and flow rate of monomer at 125 sccm a 150 sccm was decreased. Results of this work can be useful for investigation and study of deposited thin layers. The most useful can be with another work which deals with plasma diagnostics during the deposition even more closely. Then it will be possible to adjust and predict properties of deposited layers.
|
|
|
Titania suspensions for material printing
Svoboda, Tomáš ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
This bachelor‘s thesis deals with the preparation of stable suspensions of titanium dioxide applicable for material printing. A wide range of dispersive environments stabilizing the nanoparticles of titanium dioxide was investigated. Commercially available aqueous dispersion and dry titania powder was used as the source of TiO2.The properties of prepared suspensions were evaluated and the most suitable suspension was used for material printing. This thesis focused on suspension‘s stability, sizes of particles dispersed in them, and in their rheological behavior. Furthermore, we analyzed the studied the properties of printed layers by SEM, optical microscopy, DLS and analytical centrifuge. We also evaluated the photocatalytic activity by monitoring the oxidation rate of coumarin to 7-hydroxycoumarin.
|
|
|
Optimization depozition variables during material printing of titania coatings
Mlčkovová, Hana ; Králová, Marcela (referee) ; Dzik, Petr (advisor)
This thesis studies the effect of conditions in the printing material layers of titanium dioxi-de sol-gel formulations for the print properties of the resulting films – TiO2, which were pre-pared from a precursor of titanium tetraisopropoxide (TTIP). Thin films were deposited on the printing material soda lime glass and the layer thickness was controlled by repeatedly apply-ing. Prepared films were subjected to observation under an optical microscope, and the thic-kness of the layers was measured by mechanical profilometry.
|
|
|
Study of titanium dioxide photocatalytic activity by fluorescence spectroscopy
Blašková, Martina ; Vala, Martin (referee) ; Dzik, Petr (advisor)
This thesis deals with principles and methodology of evaluation of photocatalytic activity of titanium dioxide by fluorescence detection of hydroxyterephthalic acid and assessment of use this method in batch reactor. To the fluorescence study of activity we used hydroxyterephthalic acid as a primary product of oxidation terephthalic acid as a solution or in the form of immobilized layers. In the liquid phase we monitored fluorescence of hydroxyterephthalic acid by using a conventional fluorimeter and fiber spectrometer. In the solid state we monitored fluorescence of hydroxyterephthalic acid by spectrofluorometer with holder of solid samples.
|
|
|
Hybrid titania-silica layers on polymeric supports
Bednárková, Jana ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with titania-silica photocatalytic layers on polymeric supports. The theoretical part involves the study of properties and possibilities of preparing the layer and it is mainly focused on the influence of silica on the nature of layers. The experimental part of this thesis investigates the influence of layer thickness on the degradation rate of 4 different dyes.
|
|
|
Titanium Dioxide for Photovotaics
Zbořilová, Zdeňka ; Ing. Dvonka Vladimír,Ph.D. (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with the utilization of titanium dioxide for photovoltaics. The theoretical part gives a brief outline on the properties, methods of preparation and utilization of titanium dioxide mesoporous thin films for solar cells (dye sensitized solar cells and hybrid ones). The practical part includes a preparation of dye sensitized solar cells and a basic study on their behaviour during light exposure.
|
guest ::
