| Autor: |
Thoma, Andrea |
| Přispěvatelé: |
Lueken, Heiko |
| Jazyk: |
němčina |
| Rok vydání: |
2000 |
| Předmět: |
|
| Zdroj: |
Aachen : Publikationsserver der RWTH Aachen University 93 S. : Ill., graph. Darst. (2000). = Aachen, Techn. Hochsch., Diss., 2000 |
| Popis: |
The dissertation deals with the development of a dispersion process for the production of both non-magnetic and magnetic alginate beads. A combination of three different emulsifiers and silicon oil as dispersion medium is used for bead production. For bead characterization the iron and calcium content as well as the mean bead size and size distribution are determined. Light, electron and scanning force microscopy are used to describe bead morphology and surface structure. SQUID magnetometer measurements are used to determine the magnetic behaviour of the solid beads. The beads stability within a chelating agent is established by the release of the incorporated magnetite relative to the concentration of the chelating agent. To stabilize the bead chemically towards those agents, three different methods are compared. A surface coat of polyethylenimine offers the best protection. The polyethylenimin coat enables the magnetic alginate beads to separate (magnetic separation) the azo dye Kongored from its solutions. The second part of this dissertation describes studies of heating characteristics of ferrofluids and their influence on lymphocytes and HeLa cells. The ferrofluids are characterized through the determination of their iron content, particle size and inductive heating behaviour in a high frequency magnetic field. Their specific adsorption rates are determined. Cytotoxicology studies on lymphocytes enable a rough differentiation between the tested fluids concerning their cytotoxic effects. By incubing HeLa cells with a ferrofluid solution it is possible to determine the adsorbed iron content per cell in relation to the incubation period. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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