| Small magnetic particles have drawn considerable attention due to a wide range of innovative uses, including recording media, pigments, and magnetic fluids. New opportunities present themselves in the medical field, for example in drug delivery, cell separation, hyperthermia, cancer therapy, and aneurysm treatment. This thesis addresses some fundamental aspects of magnetic particle synthesis, transport, and aggregation and outlines their relevance to potential applications.; A study has been carried on a single step aerosol route synthesis of gamma iron oxide. A flame aerosol reactor is used to unravel the effects of temperature, fuel to oxidant mixing ratio, and temperature gradients on product size and quality. A modified, high throughput, nano-differential mobility analyzer is used to classify particles into narrow size regimes. Tantalum doped magnetic iron oxide nanoparticles are also synthesized to obtain a desired set of physical properties.; Various applications of magnetic particles require their effective capture in an external magnetic field. Controlled experiments are performed on the capture of micrometer and sub-micrometer sized ferromagnetic particles in a magnetic field. The results are compared to the predictions of the developed model. The variation of capture efficiency with change in several parameters, such as the magnet field strength, residence time, and particle size is established.; Aggregation of particles affects their size and morphology. To study the aggregation of magnetic particles, expressions are derived for the collision frequency function for particles whose dipoles are either randomly oriented or aligned in magnetic fields. Non-dimensional parameter constraints for the validity of these expressions are derived. These expressions are then used in a monodisperse population balance model to determine the growth rate of particles in a magnetic field. |
