Weerinda Mens

Iron oxide particles were synthesized using a spinning disc reactor (SDR) to investigate how disc surface architecture, including smooth, grooved, and spiral, and thin-film hydrodynamics control material properties. Magnetite (Fe3O4) formed in all configurations. Smooth surfaces under stable laminar flow produced the highest saturation magnetization (106.89 emu/g) and high crystallinity. This high magnetic performance is due to a nucleation-dominated regime and low surface spin disorder within the thin film. In contrast, grooved and spiral surfaces intensified micromixing and generated unimodal size distributions but induced secondary flows that increased particle collision and aggregation. Hydrodynamic modeling identified 200 mL/min as the optimal flow rate, which provides a balance between maximum turbulent energy dissipation and micromixing time to maximize magnetic performance. Compared to conventional mechanical stirring and homogenization, the SDR achieved a tenfold increase in yield efficiency (1.375 × 10-3 g/J). These results indicate that tailored surface hydrodynamics make the SDR a high-throughput and energy-efficient alternative for producing magnetic materials.