Preparation of Nanoscale Pigment Particles



Pigment particles on the nanoscale, required for applications such as transparent thin films, inks, and coatings, can be prepared by the polyol process. The fabrication of nanoscale particles of major commercial pigments, e.g., CoAl2O4 (blue), Cr2O3 (dark green), and α-Fe2O3 (red) (see Figure), is complicated by the fact that their body color is strongly related to their degree of crystallinity. The polyol method yields crystalline and colloidally stable pigments.