[Truncated] The use of a variable frequency AC-magnetometry system to measure the change of the hydrodynamic radius of a magnetic particle and so detect biomolecules in solution has been theoretically investigated. The same system has been tested with magnetic fluids intended for use in hyperthermia research. It is shown to be effective in predicting the relative heating ability of magnetic fluids. This can be used in hyperthermia research as an alternative measure of the heating ability of magnetic fluids. To find magnetic particles with the required characteristics for use in the magnetic AC-susceptibility based biosensor, the magnetic and structural properties of a range of magnetic particles were investigated. The magnetic and structural characteristics of cobalt nanoparticles in polysiloxane based carrier fluids have been studied. The differences between the magnetic properties of silica-coated and non-silica-coated cobalt particles are discussed. The fluids were shown to contain mostly unblocked particles when in the fluid state and there is evidence for multiple magnetic forms of cobalt in the dispersions. The non silica-coated cobalt particles oxidise over time while the silica-coated cobalt particles are much more stable against oxidation. Small angle neutron scattering is used to determine the clustering properties of the particles in the fluid.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2002|