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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Ionogenní fluorescenční sondy ve výzkumu koloidních systémů / Ionogenic fluorescence probes in research of colloidal system

Střondalová, Hana January 2013 (has links)
This diploma thesis studied the interaction of ionic and amphiphilic fluorescent probes with polyelectrolytes. The research of such colloidal system could be helpful in deeper understanding of interactions between polyelectrolytes and surfactants. The aim of this thesis was to determine whether ionic or amphiphilic probes are suitable for this research. Two polyelectrolytes, sodium polystyrene sulfonate and hyaluronan were used in this study. Interactions of polyelectrolytes with fluorescent probes (4-Di-2-Asp, methylene blue, dodecyl acridine orange, DiO and DiA) were studied in this work. Then cationic surfactant cetyltrimethylamonium bromide was added to this system. Samples were studied using fluorescence and UV/VIS spectroscopy. Emission and absorption spectra of these probes were recorded. This experiment was based on hypothesis that due to positive charge these probes will bind to the negatively charged polyelectrolyte. Formation of dimers or other aggegates was presumed for fluorescent probes dodecyl acridine orange and methylene blue. When 4-Di-2-Asp was used,changes in fluorescence intensity and absorption spectra in connection with possible formation of aggregates was supposed to be observed. It should be noted that formation of dimers for 4-Di-2-Asp is not described in literature. The formation of dimers wasn't clearly demonstrated during the measurement. Formation of dimers was observed only with dodecyl acridine orange. Probes DiO and DiA were used only in the study of the interaction with polyelectrolytes. These fluorescent probes showed up as inappropriate, because they adsorbed on tube walls. When cationic surfactant was added to hyaluronan-fluorescent probe system, surfactant pushed away fluorescent probe and bonded electrostatically to negatively charged groups of polyelectrolyte.

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