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Synthesis of new building blocks for bio-inspired materials in organic electronics
Viceník, Vojtěch ; Veselý, Dominik (referee) ; Richtár, Jan (advisor)
Organic electronics is a dynamically developing field addressing current challenges in many areas, including energetics and medicine. Bio-inspired materials are increasingly used in organic electronics due to their precondition of biocompatibility, functionality, and the possibility of chemical modifications. Flavins represent one of the types of bio-inspired organic materials with applications in organic electronics. This bachelor’s thesis focuses on using of bio-inspired flavin derivatives in organic electronics and the synthesis of key precursors 1,2-diketones, which are required to prepare new substituted non-condensed flavin derivatives. In the experimental part of the work, three synthetic methods of their synthesis were investigated: Sonogashira coupling, Friedel-Crafts acylation and benzoin condensation. Synthetic routes were tested, and their yields were evaluated. These key intermediates underwent reactions to form flavin derivatives.
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Conversion of a gasoline engine to burn hydrogen
Prchal, David ; Böhm, Michael (referee) ; Drápal, Lubomír (advisor)
The master’s thesis deals with the hydrogen combustion in reciprocating internal combustion engines, a topic that is becoming more important with the planned transition to low-emission mobility. basic physical properties of hydrogen, which are compared with conventional hydrocarbon fuels. Differences in terms of mixture formation, heat release rate, heat transfer, performance, emissions and other operating parameters are described. Based on the information found, a theoretical proposal for the conversion of the 1.5 TSI evo2 gasoline engine to hydrogen combustion is made, with emphasis on achieving sufficient power, a suitable torque curve, low emissions and the lowest possible conversion costs. Data from other hydrogen spark ignition engines are analysed and few different combustion models for hydrogen are developed. A simplified 1D model of the baseline engine is created and modified for hydrogen applications. A new intake cam profile is designed for the high engine load, the approximate size of the required turbocharger is recommended, intake air cooling requirements are determined and minor structural modifications to the cylinder head are proposed. The result meets the stated objectives and demonstrates that modern spark ignition internal combustion engines can be used in combination with hydrogen as a low-emission fuel with low conversion costs.
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Microbial synthesis of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)]
Dugová, Hana ; Zemanová, Jana (referee) ; Kovalčík, Adriána (advisor)
This diploma thesis studied the ability of Cupriavidus malaysiensis, Delftia acidovorans and Azohydromonas lata to produce poly(3-hydroxybutyrate-co-4-hydroxybutyrate), [P(3HB-co-4HB)], by using -butyrolactone and 1,4-butanediol as carbon substrates. The objective of this work was the production and characterisation of isolated polyhydroxyalkanoates (PHA). The theoretical part deals with the basic description and classification of polyhydroxyalkanoates. Next, the biosyntheses of the most investigated PHAs were described. The practical section of the work discusses and presents the output of the cultivation of five bacterial strains selected for the production of [P(3HB-co-4HB)], namely, Cupriavidus malaysiensis (DSM 19379), Delftia acidovorans (DSM 39), Delftia acidovorans (CCM 2410), Delftia acidovorans (CCM 283) and Azohydromonas lata (CCM 4448). The effect of the modified cultivation conditions for each of the used bacteria on the PHA production yields was discussed. The produced biomass after the cultivation was characterised spectrophotometrically, gravimetrically and by gas chromatography. Polymers were isolated from the biomass by the extraction in chloroform. The isolated polymers were characterised from the viewpoint of chemical composition, molecular weight and thermal properties by using Attenuated total reflection infrared spectroscopy, Size exclusion chromatography, Differential scanning calorimetry and Thermogravimetric analysis.
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Possibilities of waste glycerol reprocessing
Hýža, Bohumil ; Friedl, Zdeněk (referee) ; Kizlink, Juraj (advisor)
The aim of my bachelor thesis is to describe the possibilities of waste glycerol reprocessing. The thesis is purely theoretical and the information were obtained from various literary sources. Introduction of the study deals with the technological aspects of production of biodiesel by esterification of vegetable oils with methanol. Futhermore, there is described the amount of biodiesel produced in various countries around the world. In the theoretical part of the study are mentioned physical and chemical properties of glycerol and its traditional uses include the manufacture of nitroglycerin, the pharmaceutical use, etc. There are presented different technological methods for processing large quantities of glycerol too, such as steam reforming, which generates syngas which can be used for production of liquid fuels via Fischer-Tropsch synthesis. There is also desribed reduction of glycerol to propylene glycol with hydrogen. Other methods are dehydroxylation of glycerol to 1,3 - propanediol, halogenation of glycerol to produce epichlorohydrin, the catalytic dehydration of glycerol to acrolein and 3-hydroxy-propionic aldehyde, oxydehydration to polyacrylic acid, glycerol butylation over the Amberlyst catalyst and the formation of glycerol-tert-butyl ethers used as additives for fuels , polymerization of glycerol to polyglycerols, glycerol hydrothermal conversion to lactic acid catalyzed by alkali, esterification of carboxylic acids and glycerol to form glycerol esters, selective oxidation of glycerol to glyceric acid, tartronic acid and dihydroxyacetone, and glycerol as an additive for cement.
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Non - freezing heat transfer liquids on the polyol platform
Solný, Tomáš ; Čáslavský, Josef (referee) ; Kotlík, Josef (advisor)
This diploma thesis is focused on the evaluation of changes in non-freezing heat transfer liquid composed of mixture of polyols and water, used in the real solar thermic system. On the base of the research a new heat transfer liquid is proposed on the platform of 1,3-polyols. The emphasis is put on the non-toxic properties of such system revealing the two chemical candidates for a new heat transfer liquid: 1,3-propanediol and glycerol. These chemicals are mixed together with water using different volume concentrations and properties of such liquids are evaluated.
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Microviscosity probes in study of aggregation in a biopolymer-surfactant system.
Vašíčková, Kamila ; Vala, Martin (referee) ; Mravec, Filip (advisor)
The effect of cationic surfactant concentration and ionic strength on anisotropy of fluorescence of probes diphenylhexatrien and fluorescein has been investigated in the system of cationic surfactant and in the system of cationic surfactant and hyaluronan. The investigation has been done by fluorescence emission spectroscopy. Obtained anisotropy gives information about microviscosity of investigated systems. Subsequently the system of cationic surfactant and hyaluronan has been investigated by 9-(2-carboxy-2cyanovinyl)julolidine, 4-(dicyanovinyl)julolidine and 1,3-bispyrenylpropane probes. The information about the microviscosity of the system gives the integral under the emission curve of 9-(2-carboxy2-cyanovinyl)julolidine and 4-(dicyanovinyl)julolidine and the ratio between excimer and monomer of 1,3-bispyrenylpropane. It has been discovered that the ionic strength influences the anisotropy of diphenylhexatrien and fluorescein only in the fist addition of salt (concentration 0,025 mol dm-3) and that addition of hyaluronan influences the anisotropy of diphenylhexatrien and fluorescein only in samples without addition of salt. Results of measurment with 9-(2-carboxy2-cyanovinyl)julolidine and 4(dicyanovinyl)julolidine describe the formation of aggregates of catinoc surfactant with hyaluronan and characterize these aggregates from the point of microviscosity.
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Optimization of turbocharger operation to reduce thermal instability in the exhaust
Kraicinger, Vít ; Ušiak, Michal (referee) ; Böhm, Michael (advisor)
This diploma thesis deals with the reduction of instability of exhaust gas temperatures with the help of optimized turbocharger operation, for the operation of the catalyst in the optimal temperature range. The introduction describes the individual effects on exhaust gas temperatures and the effect of this temperature on emissions. Furthermore, the work describes the turbocharger's function and individual parts, especially the types of regulations used. The 1.5 TSI EA211-EVO drive unit from Volkswagen is selected for the simulations and the optimization itself. Furthermore, the work contains the creation of two models with different turbocharger control (WG, VNT), and their subsequent optimization to approximate the real speed characteristics and adjustment for the possibility of simulations of transient phenomena. At the end of the work, the mentioned optimization of turbocharger operation on the emission WLTP cycle and the subsequent comparison of the reduction of exhaust temperature instability is performed.
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Incorporation of small organic hydrophilic substances into vesicular systems
Janoušková, Vendula ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This bachelor thesis deals with the study of the encapsulation efficiency of hydrophilic drugs and their releasing from the aqueous core depending on the different composition of the components of individual liposomal systems. The hydrophilic fluorescent probe called pyranine was chosen as a model drug. The aim was to prepare liposomes which would be suitable for inhalation administration in terms of their properties. These liposomes would provide passive targeting with prolonged release time without causing negative side effects on the organism. We have succeeded in developing a standard operating procedure for the incorporation of hydrophilic drugs. Liposomal systems have been prepared consisting of the addition of various components as cholesterol, phosphatidic acid, pegylated phosphatidylethanolamine and trimethylchitosan. Furthermore, we were able to characterize the individual liposomal systems in terms of size, stability and encapsulation efficiency which are important physicochemical properties for further application potential.
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Advanced materials for organic photonics
Zvěřina, Libor ; Salyk, Ota (referee) ; Weiter, Martin (advisor)
The theoretical part of this bachelor’s thesis deals with principles, structure and optimization of organic solar cells and properties of low-molecular advanced materials – diketopyrrolopyrroles, which are used in photovoltaics. In the experimental part six derivatives of diketopyrrolopyrrole were analysed by optical characterisation. It was found that N-substitution does not influence optical properties. Length of conjugated system showed to be the key parameter. The longer conjugation is, the smaller band gap and the greater absorption intensity are obtained. Based on the previous study, four materials were chosen to prepare solar cells. Influence of thermal annealing and gradual-annealing was studied. Current density, fill factor and photovoltaic conversion efficiency were increased by annealing. Gradual-annealing have not lead to further improvement. Finally, solar cells were optimized by 1,8-diiodooctane as an additive. It was found that effect of thermal annealing can be replaced with the additive. The best photovoltaic conversion efficiency was measured on the cell with 0,2 vol. % of additive in active bulk heterojunction.
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