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Mechanical and Transport Properties of Hybrid Hydrogel Systems
Klímová, Eliška ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This master´s thesis deals with the study on mechanical and transport properties of hybrid hydrogel systems. Considering applications of hydrogels, especially in chemical industry, pharmacy, or eventually medical applications, for the study gellan and alginate-based hydrogels were selected. In order to compare individual characteristics physical and hybrid hydrogels were prepared. Gellan hydrogels were prepared in deionization aqua solution, calcium chloride dihydrate and tween 80 solution. Alginate hydrogels were prepared in calcium chloride dihydrate solution as well, and polyacrylamide with N,N´–methylenbisacrylamide. For the study of mechanical properties moisture analyser and rheology measurements were selected. Transport properties were studied using the diffusion experiments combined with UV-VIS spectroscopic detection. Concluding of this thesis is summarization of measured values, which provides comprehensive review of the problematics. It was discovered that the conveniently selected concentrations of structural components of hydrogel matrix and the additives can influence both the mechanical as well as the transport properties of studied hydrogels.
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Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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Mechanical and Transport Properties of Hybrid Hydrogel Systems
Klímová, Eliška ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This master´s thesis deals with the study on mechanical and transport properties of hybrid hydrogel systems. Considering applications of hydrogels, especially in chemical industry, pharmacy, or eventually medical applications, for the study gellan and alginate-based hydrogels were selected. In order to compare individual characteristics physical and hybrid hydrogels were prepared. Gellan hydrogels were prepared in deionization aqua solution, calcium chloride dihydrate and tween 80 solution. Alginate hydrogels were prepared in calcium chloride dihydrate solution as well, and polyacrylamide with N,N´–methylenbisacrylamide. For the study of mechanical properties moisture analyser and rheology measurements were selected. Transport properties were studied using the diffusion experiments combined with UV-VIS spectroscopic detection. Concluding of this thesis is summarization of measured values, which provides comprehensive review of the problematics. It was discovered that the conveniently selected concentrations of structural components of hydrogel matrix and the additives can influence both the mechanical as well as the transport properties of studied hydrogels.
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Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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