Micro-Encapsulation of Photonic Ink Containing Charge-Stabilized Superparamagnetic Iron Oxide Nanoparticles in Non-Polar Medium

Color-tunable surfaces are of great interest in industries such as displays, automobiles, and interiors of buildings. In this study, monodisperse superparamagnetic iron oxide nanoparticles (SPIONs) were used to prepare photonic inks with high color purity and vivid colors due to light absorption. It was then encapsulated and implemented in the form of a stable film. A photonic crystal colloidal array was prepared by stabilizing the charge of Fe3O4@SiO2 core-shell particles(130-160nm) using a charge control agent in a non-polar medium, and color conversion properties were observed. In addition, through a complex coacervation process, the SPION dispersion was processed into a double-layer microcapsule containing gelatin and polysaccharides to secure stability and color tunability by magnetic and electric fields.<br/>These microcapsules exhibited excellent mechanical strength enough to be applied to replica molding and photocuring, thus exhibiting long-term stability while maintaining flexibility and color tunability.