Synthesis and characterization of titania coated polystyrene core-shell spheres for electronic ink

As an electrophoretic core material for the electronic ink display application, polystyrene-TiO2 composite particles were synthesized. Cationic polystyrene (cPS) cores were initially prepared by surfactant-free emulsion polymerization using a cationic initiator, azodiisobutyramidine dihydrochloride (AIBA), and then the coating reaction was performed in ethanol at room temperature by hydrolyzing titanium tetraisopropoxide (TIP) in the presence of cationic polystyrene spheres at two different TIP concentrations. TiO2 coatings on polystyrene particles were characterized by FT-IR, zeta-potential measurement, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS).