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Effect of controlled degradation on the structure of high-impact polypropylene
Pragerová, Barbora ; Kratochvíla,, Jan (referee) ; CSc, Zdeněk Buráň, (advisor)
This thesis deals with the effect of controlled degradation on the structure of ethylene-propylene copolymers. The studied samples were produced in reactor as a heterophase mixture of homopolymer PP and~E/P copolymer on Ziegler-Natta catalysts. Two samples were degraded to a higher melt flow index using peroxides. These materials were then compared with reactor-prepared samples of the same melt flow index. In total, six samples of E/P copolymers were investigated, i.e. two series of three comparison samples each. For all samples, the melt flow index and the soluble fraction in xylene were determined (using the standard method according to XS-ISO 16152 and also XS-FIPA). Furthermore, in order to obtain detailed information about the structure of these materials, the granular samples were first subjected to TREF (Temperature rising elution fractionation. Each sample was separated into three fractions for which the molecular weight distribution was then determined by gel permeation chromatography (GPC). Nuclear magnetic resonance C13 NMR provided additional information. Changes in the structure of the E/P copolymers after controlled degradation were evaluated, and these degraded materials were also compared with their reactor equivalents produced directly with a higher melt flow index.
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Use of thin layer chromatography for fractionation of humic substances isolated from oxyhumolite
Hegrová, Nela ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The main goal of this thesis was to optimize the fractionation of humic substances (HS) using the method of Thin-layer chromatography, so that it can be used for physico-chemical characterization of the obtained individual organic fractions. Due to the high content of HS in the natural oxyhumolite matrix this oxidized brown coal was selected as a source of these biocolloid compounds which were isolated according to the international IHSS procedure. The sample of native oxyhumolite and oxyhumolite after extraction was characterized by thermal techniques such as thermogravimetric (TGA) and elemental analysis (EA). The above-mentioned oxyhumolite samples were further analyzed by Fourier transform infrared spectroscopy, mainly for deeper understanding of their structure in terms of an organic matrix containing HS. Characterization of isolated HSs was performed by the following thermochemical and spectrometric techniques, elemental analysis, thermogravimetry, ultraviolet and visible electromagnetic absorption (UV/Vis) molecular spectroscopy, Fourier transform infrared spectroscopy and steady-state fluorescence spectroscopy. Molecular absorption spectroscopy (UV/Vis) and steady-state fluorescence spectroscopy were used for physicochemical characterization of individual organic fractions.
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Formulation and testing of rifampicin-loaded branched polyesters nanoparticles
Balciarová, Andrea ; Dittrich, Milan (advisor) ; Šnejdrová, Eva (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: doc. RNDr. Milan Dittrich, CSc. Student: Andrea Balciarová Title of Thesis: Formulation and testing of rifampicin-loaded branched polyesters nanoparticles In presented thesis, the main attention in theoretical part is focused on nanoparticles for targeted drug delivery, their types, structure and carriers used for their preparation. Moreover, in this part there is an overview of physicochemical characteristics and preparation methods of polymeric nanoparticles applicable in formulation of pharmaceutical products. The experimental part is concerned on studying the influence of the concentration of biodegradable polymers, the presence of cationic surfactants and rifampicin as model drug substance on nanoparticles΄ size and zeta-potential. The main attention is given to nanoparticles decoration with anionic biopolymers, hyaluronic acid and xanthan gum. The simple method of preparation which is usable in nanosystems formulation that influence biological functions purposefully was tried and tested in different contexts.
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Use of thin layer chromatography for fractionation and characterization of organic matter isolated from alginite
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This diploma thesis is focused on the study of structure and physicochemical properties of organic fractions of humic substances, which were obtained by the method of thin-layer chromatography. Humic substances, which were used in this study, were isolated from a sample of Slovak alginite based on the procedure of the International Humic Substances Society (IHSS). The following analytical techniques were selected for the characterization of isolated humic substances: thermogravimetric and elemental analysis, molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR) and steady-state fluorescence spectroscopy. Each organic fraction of humic substances were characterized by molecular absorption spectroscopy (UV/Vis) and steady-state fluorescence spectroscopy. Using steady-state fluorescence spectroscopy, humic substances were found to be composed of fluorophores of humic and non-humic (protein) character. Organic fractions corresponding to the humic fluorophores were characterized by a higher content of oxygen substituents on the aromatic nukleus, a higher degree of aromaticity and also a higher molecular weight. The aim of this diploma thesis was to design and optimize the process of organic matter fractionation for the purpose of detailed understanding of the structure and properties of humic substances, which were isolated from the sedimentary rock alginite. Based on this, the practical applicability of the thin layer chromatography method to significantly reduce the molecular heterogenity of the studied humic substances was evaluated.
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Application of thin layer chromatography (TLC) for fractionation of humic substances.
Hegrová, Nela ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
The main aim of this Bachelor thesis was to suggest and optimize a method of fractionation of organic matter of humic substances using thin-layer chromatography (TLC). HS Pahokee Peat standards have been characterized by thermochemical and spectrometric techniques such as thermogravimetry, elemental analysis, UV-Vis and Fourier-transform infrared spectrometry. Molecular absorption spectrometry in the ultraviolet and visible range of electromagnetic radiation and steady-state fluorescence spectrometry were used for physicochemical characterization of organic fractions. Using fluorescence spectrometry, humic substances were found to be composed of fluorophores of humic and non-humic (protein) character. Organic fractions corresponding to the humic fluorphores were characterized by a higher aromaticity, average molecular weight and higher content of oxygen substituents on the aromatic nucleus. In contrast, the organic fractions corresponding to the protein constitutional units were distinguished by low values of the humification index. These tell us about microbial origin of these organic substances during the genesis of HS Pahokee Peat.
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Effect of catalystic system on the structure of E/P copolymers
Kolomazník, Vít ; Kratochvíla,, Jan (referee) ; CSc, Zdeněk Buráň, (advisor)
Thesis is focused on structural study of ethylene-propylene copolymers (E/P copolymers) produced by gas phase polymerization. Goal of work was to determine the effect of used catalysts on the distribution of ethylene units in the resulting material. Three E/P copolymers were prepared on commercial Ziegler Natta catalysts with diether or phthalate based internal donors. The copolymers were fractionated according crystallization ability and molar mass. Next, the mass content and the distribution of the ethylene units in the copolymer were determined in each fraction by nuclear magnetic resonance (NMR). Together with other structural analytical methods, phthalate internal donor has been found to produce ethylene blocks under certain conditions, while the diether ID lacks this ability.
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Formulation and testing of rifampicin-loaded branched polyesters nanoparticles
Balciarová, Andrea ; Dittrich, Milan (advisor) ; Šnejdrová, Eva (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: doc. RNDr. Milan Dittrich, CSc. Student: Andrea Balciarová Title of Thesis: Formulation and testing of rifampicin-loaded branched polyesters nanoparticles In presented thesis, the main attention in theoretical part is focused on nanoparticles for targeted drug delivery, their types, structure and carriers used for their preparation. Moreover, in this part there is an overview of physicochemical characteristics and preparation methods of polymeric nanoparticles applicable in formulation of pharmaceutical products. The experimental part is concerned on studying the influence of the concentration of biodegradable polymers, the presence of cationic surfactants and rifampicin as model drug substance on nanoparticles΄ size and zeta-potential. The main attention is given to nanoparticles decoration with anionic biopolymers, hyaluronic acid and xanthan gum. The simple method of preparation which is usable in nanosystems formulation that influence biological functions purposefully was tried and tested in different contexts.
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Formulation and testing of rifampicin-loaded branched polyesters nanoparticles
Balciarová, Andrea ; Dittrich, Milan (advisor) ; Šnejdrová, Eva (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: doc. RNDr. Milan Dittrich, CSc. Student: Andrea Balciarová Title of Thesis: Formulation and testing of rifampicin-loaded branched polyesters nanoparticles In presented thesis, the main attention in theoretical part is focused on nanoparticles for targeted drug delivery, their types, structure and carriers used for their preparation. Moreover, in this part there is an overview of physicochemical characteristics and preparation methods of polymeric nanoparticles applicable in formulation of pharmaceutical products. The experimental part is concerned on studying the influence of the concentration of biodegradable polymers, the presence of cationic surfactants and rifampicin as model drug substance on nanoparticles΄ size and zeta-potential. The main attention is given to nanoparticles decoration with anionic biopolymers, hyaluronic acid and xanthan gum. The simple method of preparation which is usable in nanosystems formulation that influence biological functions purposefully was tried and tested in different contexts.
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