Fabrication of polystyrene-encapsulated magnetic iron oxide nanoparticles via batch and microfluidic-assisted production

The magnetic properties of nanoparticles make them ideal for use in various applications, especially in biomedical applications. Herein, we describe the fabrication of iron oxide nanoparticles encapsulated in polystyrene (PS) using two methods: a conventional batch and microfluidic synthesis. In particular, we present a simple synthesis method of magnetic composite nanoparticles, based on the use of a microfluidic elongational flow method in a continuous-flow apparatus where magnetite particles are embedded in a polystyrene matrix. Compared to conventional batch synthesis, microfluidics-based synthesis enables precise reaction control, enhanced mixing and rapid chemical reactions, allowing flow synthesis of particles in a controllable, sustainable, and cost-saving manner that is attractive to industry. The composite particles show a high encapsulation of magnetite nanoparticles, but with an inhomogeneous size distribution; instead, the sample obtained with microfluidic approach shows a homogenous composite particle size distribution although the magnetite content is lower compared to the miniemulsion batch methods.