|
|
Surface free energy of plasma polymers
Klepáčková, Barbora Bella ; Dzik, Petr (referee) ; Čech, Vladimír (advisor)
Tato práce se zabývá studiem změn volné povrchové energie organokřemičitých plasmových polymerů na základě jejich rozdílných depozičních podmínek. Výpočet volné povrchové energie byl proveden pomocí Owens-Wendt-Kaelble, Wu a acido-bazické teorie. K měření kontaktních úhlů bylo použito čtyř různých testovacích kapalin (voda, formamid, dijodmethan a glycerol). Pro tenké vrstvy plasmového tetravinylsilanu připraveného s efektvním výkonem 2, 10, 25, 70 a 150 W byla naměřená volná povrchová energie mírně vzrůstající.
|
|
|
Label Adhesives with Enhanced Humidity Resistance
Kotrlová, Janka ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
The main topic of the thesis was to examine the hydrophobicity of labeling adhesives in the state before drying, it means their resistance against condensated moisture. The problem was solved by measuremensts of contact angle between the drop of water and glue. Measurements of dynamic viscosity and wet tack were also performed for the sake of complex characterization of the glue properties. Comparison of properties among single-component adhesives based on the acrylic copolymers alkalised with various agents was made. The impact of starches and industrial additives on glues was determined by the analysis of primary physical and chemical parameters. The purpose of the measurements was to develop a formula of the glue with enhanced atmospheric moisture resistance, that also would have the required parameters in the equilibrium. Finally, some selected glue samples were practically tested for condensation water resistance. These tests were performed in a climatic chamber with water condensating conditions.
|
|
|
Lightfastness of digital color prints
Kulhánková, Michaela ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
In this diploma thesis the current methods of color fastness evaluation of color digital prints were solved. The theoretical part provides basic information needed to understand the experiment. Samples of inkjet prints were subjected to accelerated and long-term lightfastness test. The long-term test took place in the spaces of the Faculty of Chemistry, Brno University of Technology, which fulfilled the condition of direct light in a closed room. For one year, samples were exposed and their reflection spectra were measured at monthly intervals. An accelerated lightfastness test was performed in a solar chamber with a xenon lamp. Only some samples were selected for this test because of the small space in the chambre and thw failure of the instrument. At regular intervals were measured again their reflection spectra from which the colorimetric values were calculated. After completion of the testing, the rate parameter was determined from the dependence of the loss of the normalized gamut volume on different doses of irradiation. In the case of long-term testing, it was based on data from the Hydrometeorological Institute, which gave values of direct outdoor solar radiation. In the accelerated test, the irradiation dose of the sample up to 800 nm was determined. Finally, the lightfastness of each sample was examined and compared with each other and the relevance of the accelerated test was assessed.
|
|
|
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.
|
|
|
Fabrication of transparent oxidic conducting coatings by material printing
Žáková, Michaela ; Krystiník,, Pavel (referee) ; Dzik, Petr (advisor)
Thin transparent conductive layers containing ATO nanoparticles are a modern material that has found use in a wide range of optoelectronic applications. For liquid phase deposition there were designed and prepared compositions using a „brick and mortar“ approach combined templating agents. A sol-gel solution formed of inorganic precursors of tin chloride and antimony trichloride in the presence of ATO nanoparticles was mixed with a surfactant to improve the structure and wettability of applied films. Polyethylene glycol, polyoxyethylene (20)cetylether, sodium dioctylsulfosuccinate and polyvinylpyrrolidone were used as templating agents. Thin layers of these compositions were applied by the spin-coating method. Characterized parameters were resistivity, thickness and turbidity. A resul compositions showed relatively good electrical properties and high transparency and a potencial to be used for material printing.
|
|
|
Photocatalytic layers of tungsten trioxide fabricated by material printing
Saňák, Tomáš ; Krystyník,, Pavel (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with milling of dispersed particles of WO3 using low-cost wet ball milling. Thin layers of WO3 were formed from them. These layers were characterized by profilometry, turbidity measurements, XRD and SEM. The photocatalytic activity was studied by the electrocatalytic properties of these layers. Profilometric measurements showed declining trends with milling time. XRD measurements confirmed the milling process and revealed a change in the crystalline phase during this process. Electrophotocatalytic measurements confirmed the photocatalytic activity of these layers and revealed its trends.
|
|
|
Fabrication and properties of photocatalyst layers with controlled porosity
Blecha, Tomáš ; Gemeiner, Pavol (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with fabrication of photocatalyst layers with controlled porosity and investigation of their properties. Polyvinyl pyrrolidone, polyethylene glycol and polyvinyl alcohol were used as templating agents. Prepared compositions were deposited on FTO glass using a drop-casting method and annealed at 450 °C. The structure of thin films was examined using optical and electron microscopy. The thin films were subsequently studied by photoelectrochemical measurements. Most resulting compositions showed relatively good electrical and optical properties, hinting at a potential for future use in practice.
|
|
|
Material prinitng of electroluminiscent panel
Guricová, Patrícia ; Dzik, Petr (referee) ; Vala, Martin (advisor)
This works deals with the preparation of luminescent lamp using screen printing method, characterization of individual layers and the study of spectral properties, influenced by changing printing parameters. In theoretical part are described the principles of electroluminescence as well as the method of preparation of the luminiscent lamp. Experimental part involves optimazing of printing parametres, so the homogenneous light emission is achieved. Furthermore, the influence of the change in the number of layers of active material and dielectric on the light output of the panel at the lowest working voltage is studied. The result of this work is a funcional electroluminescence lamp and an optimazed process for its preparation.
|
|
|
Transparent conducting tin oxide layers prepared from inorganic precursors
Dvorský, Vojtěch ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
The thesis focuses on the preparation of transparent electrically conductive tin oxide layers. First, a stock sol based on inorganic precursors was synthetized. Substrates were coated with a small amount of sol by spin coating or material printing to form thin layers. By modifying the solution by adding additional substances, specific coating compositions were prepared to optimize the deposition and the resulting layer properties. Selected samples were analysed by mechanical profilometry, XRD, SEM and XPS.
|
|
|
Photocatalytic properties of hybrid titania-silica layers
Sekerová, Kateřina ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
This diploma thesis is focused on the preparation of hybrid titania-silica layers. Titanium tetraisopropoxide and tetraethyl orthosilicate with Levasil were used as the precursors for TiO2 and SiO2 synthesis, respectively. The layers were deposited on substrates by material printing. Furthermore, this work is focused on the study of the rheological properties of TiO2-SiO2 sol and characterization of prepared films by XRD, SEM, ellipsometry, AFM, pencil hardnes test, optical microscopy. Optical properties were also characterized by transmitance and reflectance measurement and the functionality of these layers was demonstrated by a stearic acid degradation experiment.
|
guest ::
