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Preparation and characterisation of polysaccharide hydrogels
Kulíšková, Kateřina ; Kadlec, Martin (referee) ; Smilek, Jiří (advisor)
This bachelor thesis deals with the study of preparation and characterization of alginate hydrogels. It focuses mainly on the ionic crosslinking of alginate using divalent metal cations Ca2+, Cu2+, Zn2+, Ba2+, Fe2+ together with the trivalent cation Fe3+ in order to compare the crosslinking abilities of different oxidation states. The exogenous method was used for the preparation of alginate hydrogels and the prepared hydrogels were thus studied in the form of millimetre spheres. In the experimental part, optimization was performed to find out the optimum gelation time, which resulted in the crosslinking of the hydrogels throughout their volume. Ca2+ ions were used as a reference due to their wide application and the extensive experience with these ions at the faculty. The knowledge from the optimization was applied to the preparation of the other ions samples. The viscoelastic properties of the hydrogels were investigated by rheological measurements in the form of amplitude and squeeze tests. All ions, except Fe2+, were found to crosslink the hydrogels throughout the volume. Based on the complex modulus, the order of ions was determined according to the degree of crosslinking, The degree of crosslinking also has major impact on the degree of syneresis.
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