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Barrier Polymeric Layers for Inkjet Prints Protection
Štěpánková, Eva ; Čeppan, Michal (referee) ; Ďurovič, Michal (referee) ; Veselý, Michal (advisor)
Práce podává přehled o dostupných a využívaných metodách, normách pro testování a hodnocení světlostálosti barevných fotografií a tisků. Bylo provedeno porovnání jednotlivých platných norem a návrhů na hodnocení. Tato práce pojednává o ochraně inkjetových tisků pomocí lakování. Byl připraven lak kompatibilní s fotografickými médii. Připravená kompozice byla obohacena o UV absorbéry EVERSORB ve dvou koncentracích. Pro srovnání byly také testovány tři druhy komerčních ochranných fotografických laků. Výtisky se třemi barvivovými inkousty opatřené lakovou vrstvou, byly vystaveny jak urychlenému světelnému stárnutí v xenonové testovací komoře, tak urychlenému stárnutí v ozonové testovací komoře. Na základě měřených odrazových spekter byl vypočítaný objem barvového gamutu pomocí softwaru Volga. Byl sledován úbytek gamutů v průběhu světelného stárnutí i při expozici ozonem. Stárnutí vzorků probíhalo do ukončení testu, nebo do dosažení kritéria 30% úbytku objemu barvového gamutu. Také bylo pozorováno selhání recipročního zákona, které ukazuje na jistou nepřesnost při předpovědi dlouhé životnosti vzorků. Pomocí změny barvového gamutu byla posuzována ochrana připraveného laku před UV záření a ozonem. Studované vrstvy laků byly dále charakterizovány na prostupnost kyslíku a vodní páry.
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Degradation of Inkjet Printouts
Stančík, Jiří ; Kaplanová, Marie (referee) ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
Inkjet printing technology became a popular technology for printing digital photographs in the last decade. There is a big variety of both original and alternative (cheaper) inks and print media for the consumers. But there is a question if the cheaper material provides also comparable printout quality. For this reason, it is important to test the properties of such inkjet printouts. There are several ways how to test the lightfastness of the printouts: long term storage under environmental conditions, or short, accelerated ageing tests. The stability of printouts is affected by many factors, such as ink-receiving layer, ink composition, UV and visible light intensity and air pollutants concentration in the environment. Some inkjet printouts exposed to light usually undergo surprisingly fast fading, but light is not the only dangerous condition for inkjet printout. The two types of test targets printed with dyebased inkjet inks on various paper types were subjected to both accelerated test in a xenon test chamber and light and environmental pollutants long-term test in a sunny indoor corridor. The values of light intensity were continuously monitored and samples properties were regularly measured with a spectrophotometer. Another type of testing included accelerated ozone ageing of inkjet dyes. The colour gamuts and gamut volumes were calculated from collected spectral data. Total colour difference E*ab was also evaluated, its increase served as a tool for finding the formal printout degradation rate constant. It was found out that the dyes in ink-receiving layers of printouts underwent significant degradation in all tested conditions. The degradation rate depended on the type of used print media. The reciprocity behaviour of printouts was also studied. Recent inkjet printouts testing miss some actual ISO norm which should show the way of effective lightfastness evaluation. One of the main aims of this work was to find some new and alternative ways of inkjet printouts lightfastness evaluation. The method of printed inks concentration determination from the test charts spectrophotometric measurements was also proposed.
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Ozone gas-fading of photographs
Védlová, Petra ; Kozáková, Zdenka (referee) ; Veselý, Michal (advisor)
This bachelor thesis deals with principels of inkjet printing, ink composition and print media. The paper also focuses on stability of inkjet prints, degradation of inks by ambient impacts, mechanisms of such degradations and protection against degradation. The experimental section examines the impact of ozone on gas-fading of injekt prints, which is one of the most important factors by degradation of dyes for both clasic prints and prints with protective varnish. In conclusion two methods for assessing dye degradation – colorimetric (by calculating the volume of the color gamut) and densitometric (by calculating optical densities) – are investigated and compared.
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Catalytic fading of inkjet prints
Brablc, Tomáš ; Havlínová,, Bohuslava (referee) ; Veselý, Michal (advisor)
This thesis deals with the principles of inkjet printing, ink composition, receiving layers and print fading. The fading usually does not take place only for one reason, it is affected by more factors at a time. The catalytic fading due to light is studied. The catalytic fading takes place in overprinted areas where are situated more then one ink. The experiment was realized by the exposure of overprinted fields in accelerated ageing test. Mutual influence of two dyes from CMY together and then influence of black dye (K) on these overprinted fields were observed.
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Synthesis and properties of ceramic nanoparticles based on anionic doped composite oxides of titanium
Kašpárek, Vít ; Veselý, Michal (referee) ; Cihlář, Jaroslav (advisor)
Master’s thesis deals with synthesis of anatase and its anion doping by carbo-nitridation. Prepared samples were used for testing of the photocatalytic activity. Low-temperature anatase was synthesized at 80 °C for 6 hours and carbo-nitridatation was carried out in ammonia/tetrachloromethane atmosphere at 500 °C for 3 hours. The influence of silver content on low-temperature crystallization of anatase was studied by reaction of titanium tetraisopropoxide with water. Silver nanoparticles were prepared by reduction of silver nitrate by D-glukose and sodium citrate. One of the results is the draft for one-pot synthesis of anatase by titanium tetraisopropoxide with complexing agent (sodium citrate, ammonium citrate, citric acid). The study of photocatalysis water splitting was carried out in the presence of 20 % vol. of methanol. Anatase prepared with citric acid has the highest photocatalytic activity (Pt 0,5 %) in UV/VIS spectral region. The activity achieved 38,6 % effectiveness of TiO2 standard (Degussa P25). Doping by nitrogen didn’t lead to increase of photocatalytic activity.
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Properties of FDM technology 3D prints
Tertinská, Martina ; Přikryl, Radek (referee) ; Veselý, Michal (advisor)
This bachelor thesis is aimed at FDM 3D printing properties research. Theoretical part of the thesis sums up current knowledge about 3D printing such as it’s possible use cases and materials suitable for printing. The experimental part is focused on MakerBot Replicator Mini 3D printer and printing test samples from two different materials and testing their mechanical attributes using pull-test and break-test machinery.
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Preparation of Stuctured Thin Layers of Titanium Dioxide
Lukešová, Magdalena ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
Cílem práce bylo seznámit se s dostupnými zdroji popisujícími zkoumanou tématiku tenkých vrstev oxidu titaničitého. Na připravených tenkých filmech byla studována fotokatalytická aktivita a indukované hydrofilní vlastnosti. Transparentní filmy oxidu titaničitého byly připraveny na sodnovápenatém skle metodou sol-gel. Na přípravu TiO2 solu byl použit tetraisopropoxid titaničitý (TTIP) jako prekurzor. Přidaný polyethylen glykol (PEG) sloužil jako strukturu-řídící složka, acetyl aceton zase ovlivňoval hydrolyzační a kondenzační reakce. Pro nanášení solu na skleněné destičky byla použita technika mikropiezo depozice. Na získaných filmech byla studována fotokatalytická aktivita prostřednictvím degradace 2,6-dichlorindofenolu (DCIP). Rychlost odbourávání DCIP byla vyjádřena pomocí formální rychlostní konstanty reakce prvního řádu. Měřením kontaktního úhlu byla zkoumána smáčecí schopnost vrstev. Filmy, které byly vystaveny ultrafialovému záření, se chovaly superhydrofilně.
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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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Material printing of light dosimeters
Kabelková, Markéta ; Vališ, Jan (referee) ; Veselý, Michal (advisor)
This diploma thesis is focused on material printing of light dosimeters, especially printing of dosimeters for visible light and two types of UV radiation dosimeters. The aim of this work was to convert optimized systems from laboratory scale to pilot plant and to prepare individual systems for large-scale printing. The experimental part deals with the preparation and gradual scaling of compositions to a pilot scale, including optimization of individual components. Problems which were found during scaling up are discussed. A roll-to-roll material printer with slot-die technique was used to convert to a pilot scale. The prepared layers were exposed and their color changes was studied in detail. In addition to printing optimization, the thicknesses of the prepared layers and their resistance were determined, as well as tests of shelf life and reaction of dosimeters to ozone. According to the tests which were performed, guidelines for quality control of light dosimeters printing were compiled.
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