Encapsulation of Organic Pigment Particles Via Miniemulsion Polymerization

Different organic yellow, magenta, and blue pigment nanoparticles can be efficiently encapsulated by cosonicating pigment dispersions and monomer miniemulsions in the pigment to monomer weight ratio of 80:20, followed by polymerization. As polymers polystyrene, different polyacrylates or copolymers could be used. Efficient encapsulation was proven by means of ultracentrifugation, electron microscopic methods, and streaming potential titration. Comparing the reaction kinetics of a typical styrene miniemulsion polymerization with the corresponding “ad‐miniemulsion polymerizations” proceeding on the surface of pigment particles, an influence of the pigments' molecular structure was observed. magnified image