Patent ID: 8653185

Claim:
A method of forming an ionically-charged, encapsulated colorant nanoparticle, comprising: forming in-situ ionically-charged polyurethane monomers; forming an emulsion including the ionically-charged polyurethane monomers and colorant nanoparticles; and polymerizing or crosslinking the ionically-charged polyurethane monomers in the emulsion, the polymerizing or crosslinking chemically attaching the ionically-charged polyurethane monomers to a surface of the colorant nanoparticle to form an ionically-charged encapsulation layer on the surface; wherein prior to forming in-situ the ionically-charged polyurethane monomers, the method further includes tagging a diol or polyol reactant used to form the polyurethane monomers.