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The tetrathiofulvalene derivatives: Their synthesis and properties
Nejedlý, Jindřich ; Starý, Ivo (advisor) ; Hocek, Michal (referee)
The goal of the diploma thesis was to prepare a spectrum of electron-rich macrocyclic derivatives of tetrathiafulvalene (TTF), which should serve as electron donors in interactions with electron-deficient acceptor molecules. A two-step synthesis was used for their preparation. First, a non-cyclic three-segment precursor was prepared by a reaction of a thiolate TTF construction block with a bis(bromomethyl)aromate. Then, a reaction of this precursor with another molecule of bis(bromomethyl)derivative closed the macrocycle. The latter reaction produced mainly [2+2] macrocycles containing two TTF and two aromatic units. In most cases, larger [4+4] macrocycles were also isolated from the reaction mixture. Besides thiolate TTF unit two other thiolate units, one with extended TTF core and other with smaller trithiafulvene ring, were used analogically in synthesis. By a combination of three thiolate blocks and five bis(bromomethyl)aromates 11 three-segment components were prepared and these were converted to 11 structural types of macrocycles with [2+2] and 7 macrocycles with [4+4] stoichiometry. The resulting macrocycles were characterized by 1 H a 13 C NMR spectroscopy and analyzed by a gel permeation chromatography. Their structures were also confirmed by high-resolution mass spectroscopy. Interaction...
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Optimizing the determination of distribution of surfactant at phase separation in polymer-surfactant system
Sátorová, Kateřina ; Pekař, Miloslav (referee) ; Mravec, Filip (advisor)
This diploma thesis is focused on the determination of distribution a surfactant at phase separation in polymer-surfactant system. Sodium hyaluronate of three molecular weights was chosen as a polymer, CTAB was used as a surfactant. The experiments were performed in an environment of 0,15 M NaCl. The measurement of the CTAB concentration in samples was based on the formation of coloured complexes of CTAB and picric acid in chloroform. UV-VIS spectroscopy was used for the detection of these complexes. The content of CTAB was determined in four gels of different composition (2% Hya + 200 mM CTAB, 2 % Hya + 50 mM CTAB, 0,5 % Hya + 200 mM CTAB, 0,5 % Hya + 50 mM CTAB). All gels were gradually washed five times with 0,15 M NaCl. The content of CTAB was determined for newly prepared gels and for gels after 2 and 4 months since the preparation. Initial concentrations of CTAB and hyaluronan have greater influence on the distribution of CTAB after phase separation, than the molecular weight of hyaluronan. The content of CTAB in newly prepared gels and after 4 months since preparation is very similar and demonstrates the stability of the system.
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Dialysis study of hyaluronan-surfactant interactions
Šejnohová, Michaela ; Venerová, Tereza (referee) ; Pekař, Miloslav (advisor)
This diploma thesis is concentrated on the interactions between polyelectrolyte (hyaluronan) and cationic surfactant (CTAB). The experiments were performed in an aqueous solution and in an environment of physiological ionic strength (0,15mmoldm-3 NaCl). The determination of the surfactant concentration in solutions was based on the formation of colored complexes of CTAB and picric acid in chloroform. The concentrations of surfactant were measured by UV-VIS spectroscopy. The stability of CTAB+HyA was examined by a dialysis method. The results showed that, regardless of the environment, the presence of HyA in solution reduces the number of free molecules of CTAB which can be determined in the sample. It has been proved that there is an interaction between HyA and surfactant and that CTAB has greater affinity for HyA then for the picric acid. The stability of CTAB+HyA was determined by dialysis of 120 hours. After that time, the concentrations of the retentate and permeate were settled. The results showed that in the membrane remains a certain amount of CTAB bounded to hyaluronan. The system can be suitable for the preparation of targeted carriers of biologically active substances.
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Comparative study of interaction between surfactant and hyaluronan and different polyelectrolytes.
Stiborský, Filip ; Pravda,, Martin (referee) ; Pekař, Miloslav (advisor)
In this diploma thesis, the interactions between polyelectrolyte and surfactant at low and also at high concentration were studied. There was used pyrene as fluorescent probe during the fluorescence spectroscopy measurement, a cationic surfactant cetyltrimethylammonium bromide and as a main polyelectolyte has been chosen sodium polystyrene sulfonate at 1 MDa molecular size. In the medium containing 0.15 M NaCl we could observed a creation of the complexes – precipitates in the surrounding of CMC concentration and behind of this concentration. In the mixtures containing sodium polystyrene sulfonate and hyaluronan together, there was stronger tend to keep aggregation properties of sodium polystyrene sulfonate during difference concentration ratios. Beyond CMC concentration, hyaluronan starts to influence the aggregation properties of the system as well.
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Diaphragm discharge in organic dye solutions
Pajurková, Jana ; Možíšková, Petra (referee) ; Kozáková, Zdenka (advisor)
This Diploma thesis was focused on the degradation of dyes Saturn Red L4B (Direct Red 79) and Saturn Blue LB (Direct Blue 106) by DC diaphragm discharge (DC-DD). Supplied power was between 160 and 180 W. Conductivity and pH were changing at each electrode area during the DC diaphragm discharge, therefore the effect of pH and conductivity changes on the dye solution itself were examined. All samples were measured by UV-VIS spectrometer in the wavelength range of 300–800 nm. No significant dependence of dye absorption spectra on conductivity was observed, while pH significantly affected the absorption curves of dyes. Ageing of dye spectra showed significant changes of Saturn Red L4B. Next task was the comparison of dyes destruction efficiency by DC-DD, audiofrequency diaphragm discharge (AF-DD) and electrolysis. Dye decomposition by AF-DD was not observed at set conditions (voltage of 80–120 V, current of 2.2 A and frequency of 2 kHz). In the case of DC diaphragm discharge the electrolysis played an important role. Decomposition efficiency of the dyes by electrolysis was up to 15 %. The pumping effect in the DC diaphragm discharge was also investigated. Although the individual electrode areas were linked only by a small pinhole in a nonconductive barrier (the pinhole diameter of 0.3 mm), solutions of the anode and cathode compartment interacted with each other up to 10 %. Finally, the degradation products of Saturn Red L4B treated by DC-DD in two electrodes parts are also described. Decomposition products were determined by high performance liquid chromatography (HPLC) combined with the mass spectrometer.
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Diaphragm discharge in organic dye solutions with focus on electrolytic decomposition
Davidová, Jaroslava ; Brablec, Antonín (referee) ; Kozáková, Zdenka (advisor)
This Diploma thesis is focused on physical and chemical effects which contribute to the decomposition of organic dyes by diaphragm discharge generated in water solutions. Due to the application of DC high voltage source in continuous regime, there is an effect of electrolysis contributing to the dye decomposition by diaphragm discharge. The aim of this work was to find out when the electrolysis is running (or when is the moment of discharge breakdown) and which factors influence the breakdown. The other goal was decomposition of selected textile and food organic dyes by electrolysis itself. In the theoretical part, theory about creation of electrical discharges in aqueous solutions is noted and various types of underwater discharges are described. Background researches about underwater electrical discharges used in the world are mentioned as well as the use of diaphragm discharges and various ways how to remove organic dyes from wastewater. Finally, theories of electrolysis, UV-VIS spectroscopy and basis of other analytical methods useful for detection of organic molecules are described. Experimental part is oriented to experiment procedure which was carried out in a reactor with separated electrode areas. Separation was made by dielectric diaphragm with a pinhole in the centre. Its initial diameter was 0.4 mm. Used chemicals and course of experiments are described in this part, too. First, the breakdown moment in the reactor was investigated (i. e. determination, when only electrolysis was operating) by formation of hydrogen peroxide and measurement of dynamic (time resolved) electrical characteristics. Next, decomposition of selected dyes by electrolysis was carried out. As the decomposition was related to decolorization of the solution, UV-VIS spectroscopy in the range of 350–700 nm was used for determination of dye concentration. Next part focused on results presents various factors which had an effect on breakdown of diaphragm discharge. These factors are kind of used electrolyte, initial conductivity of solution, kind of dye, temperature of solution and type of reactor (or solution volume). From the result, the most important factor is initial solution conductivity. After the determination of the breakdown moment, the electrolysis of organic dyes was performed. The applied current was 10 mA, initial conductivity was 500 µS/cm and used electrolyte was NaCl. Moreover comparison of dye decomposition in dependence on the different applied power was realized. From this comparison one can assume, there is no significant contribution of electrolysis (the efficiency is approximately 15 %) to the diaphragm discharge in aqueous solution.
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Solubilizattion properties of polysaccharides
Lenartová, Radka ; Foglarová, Marcela (referee) ; Pekař, Miloslav (advisor)
In this diploma thesis were studied solubilization properties of polysaccharides by using hydrophobic solutes (Sudan Orange G, Sudan Red G, (±)-alpha-Tocopherol, Pyrene, Perylene, Nile red), which were represented by alkyl derivates of hyaluronan. At first, a behaviour of individual hydrophobic solutes was investigated in variously polar solvents (Methanol, 1 Propanol, Chloroforme, Cyklohexane, n Heptane) and in the environment of varying ionic strength (water, 0.1 M and 0.4 M NaCl). Afterwards, solubilization properties of Sodium Dodecyl Sulfate model solubilizated the hydrophobic solutes into a core of micelles was examinate. We were interested in the solubilization capacity as the mol of solubilized molecules per mol micelles of surfactant corresponding with a state of micelles saturation. In the case of the solubilization of (±)-alpha-Tocopherol into the core of micelles, it was not possible to determine the solubilization capacity. So we changed the determination of universally solubilization power. The solubilization power is defined as mol of molecules solubilized per mol surfactant relative to the quantity solubilizate at the micelles saturation. Model system of Sodium Dodecyl Sulfate as a simple surfactant carrying a negative charge as the alkyl derivates of hyaluronan was selected bacause of its characteristics.The surfactant forms unimolar micelles and its critical micelle concentrations and aggregation numbers are tabelated for the investigated microenvironment. The main aim of the study was investigating of hydrophobic domains of alkyl derivates of hyaluronan as free places for incorporation hydropbobic solutes in the microenvironment of varying ionic strength. The critical aggregation concentrations were determined by the Pyrene 1:3 ratio method. For the research of micropolarity of alkyl derivates hyaluronan’s domains were selected two concentrations of derivates for the next research of solubilization experiments - the first concentration near the critical aggregation concentration and the second concentration above it. The effect of concentration of Pyrene on a core polarity of derivates was investigated. We discovered the influence of the concentration and the other we found a stationary area of the concentration. In the end we investigated the influence of preparation of solutions of derivates of hyaluronan on the core polarity by the concentration of pyrene which corresponds to the stationary area. The study of solubilization properties of alkyl derivates of hyaluronan is not a simple case as we assumed. When we measured spectra of the absorbance, higher concentration of derivates of hyaluronan belittle absorbance of solubilizates. At the experiment of solubilization with Sudan Red G we found out that Sudan Red G is not able to solubilizate into the hydrophobic core of micelles of hyaluronan’s derivates because of lipophilic or steric effects. We had to change Perylene as a new solubilizate. From the measured emission spectra we found saturation micelles. We can express the solubilization power of hyaluronan’s derivates for the concentration of Perylene. The main aim of the diploma thesis was to determine optimal way of the preparation of hyaluronan’s derivates solutions with required degree of solubilization.
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Complex physicochemical analysis of natural medicinal water
Machátová, Nikol ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis is focused on the study of the content humic substances in natural medicinal water. Humic substances extracted from this water were characterized by UV-VIS and FTIR spectroscopy, hereafter microbiological tests were performed. The main aim was determine the content HS using the norm ČSN 75 7536 and the calibration curves of standard fulvic acid Suwannee River. Another part of this bachelor thesis was focused on spectrometric characterization HS after different degree of purification. Humic substances were characterized by absorption coefficients and FTIR spectroscopy.
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Electrolytic properties of hyaluronan solutions
Suchá, Šárka ; Smilek, Jiří (referee) ; Chytil, Martin (advisor)
This batchelor thesis deals with electrolytic properties of hyaluronan in aqueous solutions. In this study measuring of conductance, acid-base and conductrometric titration, and UV-VIS spectroscopy were used. The measuring of conductance was made on the solutions of different concentrations of hyaluronic acid and of different ionic strength. Acid-base titrations were performed in water solution and conductometric titrations were performed in 0,3mmol.dm–3 solution of sodium chloride. UV-VIS spectra of hyaluronic acid were measured in solution with addition of acid, base and in buffer solution. Values of pKa obtained from the above mentioned measurements was between 2,8–6,5.
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Study of influence of organic dye structure on their decomposition in the diaphragm discharge in liquids
Pajurková, Jana ; Fasurová, Naděžda (referee) ; Kozáková, Zdenka (advisor)
The main goal of presented thesis is to study the influence of organic dyes structure on its degradation in diaphragm discharge in liquids. Diaphragm discharge is a kind of non-thermal plasma that can be generated in liquids by the application of high voltage. In plasma channels (so-called streamers), many physical and chemical processes are formed. High electrical field, shock waves and last but not least emission of electromagnetic waves in the range of visible and ultra-violet radiation appear among physical processes. The most important chemical process is generation of active species. These species initiate chemical reactions and could attack molecules of organic compounds contained in water solution. The reason why organic dyes were chosen in this study is its visible destruction, because it is related to its decolouration. Further, UV-VIS spectroscopy for the determination of concentration during the experiment can be used. Organic dyes are good models of organic substance often contained in waste water and for which removal classical biological, chemical and physical methods aren’t sufficient. Selected dyes were mostly from the group of azo-dyes: Acid Red 14, Acid Red 18, Acid Yellow 23, Direct Blue 53, Direct Red 79, Direct Red 80, Direct Yellow 29, Food Yellow 3 and further, Acid Blue 74 (indigotic dye) and Direct Blue 106 (oxazine dye). Experiments were carried out in a special batch discharge reactor with the anode and the cathode spaces divided by a non-conductive barrier, where the diaphragm with a pin-hole was placed. Measurement showed different removal in the anode and cathode space. We have supposed it was caused by different streamers features and energetic conditions. Dyes were decomposed with higher efficiency in the anode space where the final concentration reached 40 % of the initial concentration while it remained about 90 % in the cathode space. In this thesis the influence of dyes structure on the dye decomposition by electrical discharge was investigated. Dyes consisted of small molecules and dyes with many substitutes bounded on aromatic ring were decomposed more easily than dyes consisted of big molecules. The shift of characteristic wavelength on both directions (to shorter as well as longer wavelength) was observed during the experiments especially when the Direct dyes were decomposed. This phenomenon was probably due to the formation of intermediate product, which have different characteristic wavelength than the primary compound. In general, colourfulness is given by long conjugated systems of double bonds with substitutes bounded on an aromatic ring. Each change in the molecule structure provides the colour change and this could be the possible reason of the shift of characteristic wavelength. The other task was the comparison of degradation process efficiency by the mean of electrolysis and diaphragm discharge. Results showed that electrolysis (30 W) was more convenient for degradation of dyes consisted of small molecules while diaphragm discharge (130170 W) suited for complex molecules. For degradation of small molecules, oxidation on the anode assumed to be the most effective process that is initiated by electrolysis. For degradation of big molecules, attack of active species produced by the discharge is necessary.
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