Synthesis of Composite Nanoparticles with Magnetic Properties
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There is a lot of research being done in inorganic nanoparticles for use in biomedicine as magnetic resonance imaging contrast-agents, where especially gadolinium is very interesting because of its 7 unpaired electrons. In this work a noval rout of synthesising cubic-shaped Fe3O4 nanoparticles, by using a sodium oleate batch from J. T. Baker, have been found. The synthesis rout differs from earlier reported methods by making a precursor of metal composite oleate before the thermal decomposition reaction. This general and novel route of synthesis have been used to synthesise cation-substituded MXFe3-XO4 (M = Co, Gd) nanoparticles. Several compositions of cobalt iron oxide have been made with highly monodisperse cubic-shape and good size control, with particle size ranging from 4,46 nm to 13,29 nm. The same synthesis rout have been used to synthesis GdXFe3-XO4 particles with the compositions Fe:Gd = 1:0,1 and 1:0,5 where the different compositions gave spherical and cubic-shaped nanoparticles respectively, and the size range was between 1,2 nm and 7,4 nm. The synthesis rout has been proven to be able to synthesise Gd2O3, where the reaction time have been optimized to 4 hours. Samples of both the gadolinium iron oxide compositions and the pure gadolinium oxide have been phase-transferred to an aqueous media before their contrast-agent abilities were tested with MRI analysis. The MRI showed the samples increases the signal in the surrounding protons in both T1-weighted and T2-weighted images showing potential for further use of this synthesis rout in the production of MRI contrast-agent.