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Study of Inkjet Inks Degradative Processes
Samcová, Kateřina ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis follows the degradation of inkjet print by ultraviolet radiation and ozone effect for different types of papers. Colour test charts for the evaluation of accelerated ageing effect of ultraviolet light and gas fading were designed. These test charts were printed by dye-based inks on selected receiving media and exposed to ozone-enriched environment, UV radiation and their combination. The colorimetric values L* a* b* were calculated from spectral data of all patches of the test charts. The ozone effect on the prints was evaluated in the terms of total colour difference and dye concentration. The degradation of dye caused by ozone was observed also in a long-term period, after the contact of sample with ozone was terminated. Results of printed samples accelerated ageing by UV radiation and those that were influenced by the ozone effect were evaluated in the same way. It was found out that UV radiation and ozone treatment have a different effect on the degradation of dyes. The degradation rate is also strongly influenced by the receiving layer composition of papers used for inkjet printing. Also the catalytic effect of dyes was evaluated.
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Evaluation of Inkjet printout degradation
Blažková, Michaela ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with the study of inkjet print degradation on handmade paper modified by polymer layer containing light stabilizers and inorganic filler. The polymer layer coated on the medium consisted of polyvinylalcohol, titanium dioxide and light stabilizer. The influence of light promoted degradation and light stabilizers was observed. The experiments were carried out on Q-SUN Xenon Test Chamber device, Model Xe-1-B/S. Colorimetric values of test chart were measured and the influence of different light stabilizers on the color difference between original and faded sample was evaluated.
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Dielectric layers fabricated by material printing
Olejníková, Marie ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This master‘s thesis deals with the use of the material printing method for fabrication of dielectric films. Final high- dielectric composite film consisted of BaTiO3 based inkjet-printed layer and spin-coated polyvinylpyrrolidone (PVP) layer. The effect of ball-milling on BaTiO3 suspension was studied by DLS a XRD methods. Printing formulation and parameters of inkjet printing were optimized with respect to the surface morphology of printed BaTiO3 films using contact profilometry method. Impedance analysis was used to determine the value of effective dielectric constant of the final dielectric composite film using thin film capacitor structure. Effective dielectric constant of composite dielectric film was 4,9 ± 0,4.
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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.
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Barrier properties of varnishes for protection of photographs
Lokotschová, Radka ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
In this diploma thesis the basic principles of inkjet print, ink composition, print media and degradation mechanisms of ink dyes are summarized. The thesis deals with study of varnish barrier properties in coloured inkjet prints. Permeability of water vapour and oxygen (parts of atmosphere) depending on different coatings are tested there. In addition the influence of ozone on degradation of dyes was studied, while ozone was permeating through barrier varnish layer of inkjet print. Ozone plays an important role in degradation processes of the inkjet prints and it also causes a gas-fading. Concentrations of acting ozone were established by iodometric titration. Simultaneously kinetics of degradation of Orange 7 was studied on indicator papers.
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Evaluation of pollutant impact on photographic images
Brablc, Tomáš ; Reháková, Milena (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with the impact of pollutants on colour photography made by inkjet printing technology. There are summarized basic principles of inkjet printing, composition of inks and negative factors influencing the printout quality. The ozone was studied in the experimental part, because it has the stongest degrading effect of all common pollutants. The accelerated ageing test with changing the concentration of ozone and the time of exposure was performed. The test scales were made by using two different inks. The L*a*b* values and optical densities of selected fields were calculated from the reflectance spectra of 918 colour fileds. The colour gamut and its volume were calculated from the L*a*b* values. The changes of colour gamut volume correlated with the changes of optical densities. It emerged that using the colour gamut as the instrument of evaluation of the inkjet printout dyes degradation rate is eligible and it is suitable to recommend this method for the ozone accelerated tests.
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Inkjet prints ageing by ozone and light
Pasečná, Klára ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
This thesis is focused on the effect of ozone on ink-jet prints. The knowledge about print technologies, materials for ink-jet printing, influence of environmental factors on the prints degradation and the methods of print lifetime estimation are discussed in the theoretical part of the thesis. Test-charts of 108 samples of C, M, Y primary colours and their overprints were prepared. I used two types of papers designed for ink-jet printing. These samples were exposed the effect of ozone in various concentrations to perform an accelerated aging experiment. Optical density values, La*b* coordinates, colour difference values were calculated from the measured spectral data. Changes of colours of the ink due to ozone exposure were determined and discussed. The validity of the reciprocal law due to ozone exposure was studied, too. The reciprocal behaviour was not confirmed for both types of the studied papers.
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Study of Inkjet Inks Degradative Processes
Samcová, Kateřina ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis follows the degradation of inkjet print by ultraviolet radiation and ozone effect for different types of papers. Colour test charts for the evaluation of accelerated ageing effect of ultraviolet light and gas fading were designed. These test charts were printed by dye-based inks on selected receiving media and exposed to ozone-enriched environment, UV radiation and their combination. The colorimetric values L* a* b* were calculated from spectral data of all patches of the test charts. The ozone effect on the prints was evaluated in the terms of total colour difference and dye concentration. The degradation of dye caused by ozone was observed also in a long-term period, after the contact of sample with ozone was terminated. Results of printed samples accelerated ageing by UV radiation and those that were influenced by the ozone effect were evaluated in the same way. It was found out that UV radiation and ozone treatment have a different effect on the degradation of dyes. The degradation rate is also strongly influenced by the receiving layer composition of papers used for inkjet printing. Also the catalytic effect of dyes was evaluated.
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Study of thin film organic materials thickness
Hegerová, Lucie ; Veselý, Michal (referee) ; Zmeškal, Oldřich (advisor)
The diploma thesis deals with the determination of thickness and refractive index of thin organic films using image analysis. In the theoretical part there are described principles of the methods, which are used to prepare the films (spin coating, inkjet printing, vapour deposition), the characteristics of thin films, ways of finding out the thickness and refractive index of substances (weight methods, electric methods, method based on measurement of absorption coefficient of light, interference microscopy, ellipsometry) and also image analysis (harmonic and wavelet analysis). Interference microscope Epival - Interpako (Carl Zeiss Jena), digital camera Nikon Coolpix 5400 and computer were used for the determination of thickness and refractive index. The thicknesses of layers were set on the basis of interference images of edges and grooves – both from the side of the metal contact and the side of underlying glass. The refractive indices of thin layers were then set using the recorded figures. In the final part of the thesis there are discussed the results of interference images photographed along the full length of the aluminium contact which are used for measuring electrical characteristics of DPP structures. The produces are thicknesses and refractive indices of individual layers.
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Evaluation of Inkjet printout degradation
Blažková, Michaela ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
This diploma thesis deals with the study of inkjet print degradation on handmade paper modified by polymer layer containing light stabilizers and inorganic filler. The polymer layer coated on the medium consisted of polyvinylalcohol, titanium dioxide and light stabilizer. The influence of light promoted degradation and light stabilizers was observed. The experiments were carried out on Q-SUN Xenon Test Chamber device, Model Xe-1-B/S. Colorimetric values of test chart were measured and the influence of different light stabilizers on the color difference between original and faded sample was evaluated.
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