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Hydrogels amino-dextran-surfactant: phase diagram
Daňková, Kristýna ; Hurčíková, Andrea (referee) ; Pekař, Miloslav (advisor)
This bachelor thesis deals with a study about hydrogel systems based on the physical interactions of the oppositely charged particles, specifically interactions between positive polyelectrolyte and negative detergent. The phase diagrams were created based on the visual evaluation of results of the laboratory experiment, which is a part of this thesis, for in advance chosen concentration of the polymer diethylaminoethyl-dextran hydrochloride and detergents sodium dodecyl sulphate and sodium tetradecyl sulphate. These phase diagrams characterize incurred dextran systems.
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Influence of molecular weight of polymers on phase-separated hydrogels
Kolomá, Nikola ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on study of individual systems of hyaluronan mixtures. All mixtures of hyaluronans they were ready at molecular weights of 15-30 kDa, 80-150 kDa, or 1500-1750 kDa. These individual molecular weights were combined in different ratios most often in ratios of 70:30, 50:50 and 30:70. Septonex surfactant was used for all mixed samples and CTAB was used for last experiment too. At first the gel samples were prepared by a dry route of individual powders with accurately calculated batches. All solutions were prepared wet route with stock of exactly calculated concentration. Physical gels were prepared by combinations of Septonex and hyaluronan with the different molecular weights. In solution formed irregular shapes which we could describe as "marbles" or "beads". After the sample was to stand, the individual „marbles“ of the gel were formed whole mass. Was done too many experiments with physical gels, which has been carried out behavior of mixtures hyaluronans with different molecular weights. All physical and chemical properties were observed by the eye, described and in the and were photographed. Was used hydrophil dye in experiments and served for better visualize comparison samples between themselves. The last experiment was rheological measurement with which is possible characterize viscosity od individual samples.
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Interaction of hyaluronan with surfactant CAE
Trtek, Jan ; Pekař, Miloslav (referee) ; Hurčíková, Andrea (advisor)
The diploma thesis is focused on the study of interactions between hyaluronan of various molecular weights with CAE surfactant. This surfactant does not have the exact composition and there is not known their molecular weight. One of the main parameters needed to describe the interactions between surfactant and hyaluronan, there is the determination of critical micellar concentration. The value of critical micellar concentration of CAE is not known yet. All measurements were made for solutions in aqueous solution and 0.15 M NaCl. The determination of the molecular weight of this surfactant was performed by the technique SEC-MALS-dRI. High resolution ultrasonic spectroscopy was chosen to determine the critical micellar concentration and tensiometry was chosen as a complementary method. The interactions of CAE surfactant with polysaccharide of hyaluronan were showed by high resolution ultrasonic spectroscopy and densitometry. Compressibility was calculated from ultrasonic velocity and density.
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Hyaluronan-Micelle Aggregates and their Potential for Nanomedicine Applications
Pilgrová, Tereza ; Burgert, Ladislav (referee) ; Reháková, Milena (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the study of preparation and characterization of hyaluronan-micelle aggregates. The theoretical part deals with drug delivery systems, characterization of used materials and methods especially fluorescence spectroscopy, dynamic light scattering and turbidimetry. Methods of determination of measured data are summarized in the experimental section. The result section is divided into two subsections dedicated to different preparation methods of hyaluronan-surfactant complexes. Induced aggregates of hyaluronan with Septonex are characterized in terms of their origin and stability, and the results are compared with previously studied surfactants CTAB. In the second part are discussed so-called decorated micelles, their formation, properties and stability.
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Surfactant organogels as delivery systems for medical and cosmetic oils
Koláčková, Petra ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
The aim of this thesis was to investigate the possible using of surfactant organogels in the cosmetic industry. Mainly, we focused on the ability of sugar surfactants to bind with medical (cosmetic) oil. With further heating, we observed transformation to the organogels. During the preparation of sugar surfactants, we decided to use the transesterification method. Another target was to verify functionality of this method and then proposed modifications to this process. Using Nuclear Magnetic Resonance, we checked the chemical structure of our sugar-based surfactants.
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Phase separation in dilute solutions of polymers and surfactants
Klementová, Tereza ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This bachelor's thesis deals with conditions of phase separation in system of polyelectrolyte (sodium hyaluronate) and cationic surfactant (cetyltrimethylammonium bromide). Separated phase was studied by fluorescence measurement with Nile red as a fluorescence probe and there were also specified rheological properties using flow tests and frequency oscillatory tests. Behaviour of separated microgel was also observed in solution of NaCl.
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Effect of crowding agents on DNA-surfactant interaction
Sovová, Šárka ; Hurčíková, Andrea (referee) ; Pekař, Miloslav (advisor)
Tato diplomová práce se zabývá vlivem zaplňovacích činidel na interakce v systému DNA-tenzid. DNA o velikosti 4017 párů bází byla připravena polymerázovou řetězovou reakcí, jako templát byl použit plasmid pSB-E1g. Polyetylen glykol (PEG) byl použit jako zaplňovací činidlo a jeho vliv na DNA-tenzid interakce byl zkoumán experimenty založenými na fluorescenci a gelové elektroforéze. Také byl studován vliv iontové síly za použití NaBr na interakce DNA-tenzid za použití zaplňovacího činidla. Data byla vyhodnocena a evaluována v této práci. V úvahu byl brán i možný vliv polyetylen glykolu na kritickou micelarní koncentraci (CMC) tenzidu, bylo provedeno měření CMC pomocí ultrazvuku s vysokým rozlišením, avšak nebyl zjištěn žádný značný vliv zaplňovacího činidla na CMC tenzidu. Část této práce bude zahrnuta v publikaci s anglickým názvem Combined role of macromolecular crowding and cationic surfactant in efficient DNA condensation.
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Heat insulating moulded refractory materials
Novotný, Radoslav ; Lang, Karel (referee) ; Raschman,, Pavel (referee) ; Havlica, Jaromír (advisor)
Doctoral thesis is focused on the study, research and development of heat insulating moulded refractory materials. The replacement of shaped instead of unshaped refractories is recently and strongly industrially demanded and belongs to ongoing research topics. With the increasing demand of energy savings, the excellent insulation properties are essential. The insulating properties of castables are the result of targeted porosity formation. The porosity is coming from the controlled air intrusion into material resulted to foamed structure. The foaming process was achieved by mixing of separately prepared aqueous foam into raw castable slurry or by in situ foaming of intensively mixed castable slurry with the surfactant additive. Nevertheless, the study of foam behaviour and the influence of additives on binder hydration and setting processes (i.e. calciumaluminate cement) was substantial for successful preparation of the experimental samples. The two types of the experimental samples were prepared. The first one was based on mixing of kaolin slurry with pre-prepared aqueous foam, whereas the de-aglomeration ability of kaolin specie was utilized to water-particle film formation. In situ foaming of multicomponent system is the second one. The both processes brought some negative attributes, so the optimal properties of prepared castables were achieved by their combination.
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Interactions between Hyaluronan and Surface Active Substances
Krouská, Jitka ; Burgert,, Ladislav (referee) ; Lehocký,, Marián (referee) ; Vikegard,, Peter (referee) ; Pekař, Miloslav (advisor)
Vliv hyaluronanu na micelizaci tenzidů byl studován různými fyzikálně-chemickými metodami. Byly zvoleny dva kationaktivní tenzidy, a to tetradecyltrimethylammonium bromid (TTAB) a cetyltrimethylammonium bromid (CTAB). Metoda izotermické titrační kalorimetrie byla využita pro stanovení entalpie micelizace, tenziometrie popisuje povrchové vlastnosti daných vzorků. Byl sledován také vliv různé molekulové hmotnosti použitého hyaluronanu a délka alkylového řetězce tenzidu na agregační chování daného systému. Výsledkem jsou hodnoty kritické micelární nebo agregační koncentrace tenzidu. V neposlední řadě se diskutuje využití agregátů hyaluronan-tenzid jako možné nosiče pro cílenou distribuci léčiv.
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Solubilization properties of polyelctrolyte - surfactant complexes
Malá, Michaela ; Pekař, Miloslav (referee) ; Venerová, Tereza (advisor)
In this diploma thesis has been studied system of hydrogels based on interaction between polyelectrolyte and surfactants, especially their solubilizing properties. As a surfactant was used ionic cationic cetyltrimethylammonium bromide (CTAB). As a polyelectrolyte was chosen native anionic hyaluronan with various molecular weight - 0,3; 0,9; 1,6 MDa and with different concentration - 2%, 4%, 6% wt. Solubilization experiments were realized with hydrophobic dye sudan red G. The whole system was prepared in the simpliest model system of physiological solution 0,15 M NaCl and in water. At the prepared gels was investigated their stability, influence of the environment, molecular weight and concentration on solubilization. Gels were prepared in rate hyaluronan-surfactant 1:1. The purpose of this diploma thesis was to find and optimize the appropriate procedure for determining solubilization capacity by using UV-VIS spectrophotometry.
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